Fixed all compilation errors;

source/contract/contract-samples/src/main/java/com/jd/blockchain/contract/ReadContractImpl.java

@@ -1,7 +1,7 @@
 package com.jd.blockchain.contract;
 
 import com.jd.blockchain.crypto.HashDigest;
-import com.jd.blockchain.ledger.KVDataEntry;
+import com.jd.blockchain.ledger.TypedKVEntry;
 
 @Contract
 public class ReadContractImpl implements EventProcessingAware, ReadContract {
@@ -24,7 +24,7 @@ public class ReadContractImpl implements EventProcessingAware, ReadContract {
     @Override
     @ContractEvent(name = "read-key")
     public String read(String address, String key) {
-        KVDataEntry[] kvDataEntries = eventContext.getLedger().getDataEntries(ledgerHash, address, key);
+        TypedKVEntry[] kvDataEntries = eventContext.getLedger().getDataEntries(ledgerHash, address, key);
 
         if (kvDataEntries != null && kvDataEntries.length == 1) {
             return kvDataEntries[0].getValue().toString();
@@ -35,7 +35,7 @@ public class ReadContractImpl implements EventProcessingAware, ReadContract {
     @Override
     @ContractEvent(name = "version-key")
     public Long readVersion(String address, String key) {
-        KVDataEntry[] kvDataEntries = eventContext.getLedger().getDataEntries(ledgerHash, address, key);
+        TypedKVEntry[] kvDataEntries = eventContext.getLedger().getDataEntries(ledgerHash, address, key);
 
         if (kvDataEntries != null && kvDataEntries.length == 1) {
             return kvDataEntries[0].getVersion();

source/contract/contract-samples/src/main/java/com/jd/blockchain/contract/TransferContractImpl.java

@@ -2,7 +2,7 @@ package com.jd.blockchain.contract;
 
 import com.alibaba.fastjson.JSON;
 import com.jd.blockchain.crypto.HashDigest;
-import com.jd.blockchain.ledger.KVDataEntry;
+import com.jd.blockchain.ledger.TypedKVEntry;
 import com.jd.blockchain.ledger.KVDataVO;
 import com.jd.blockchain.ledger.KVInfoVO;
 
@@ -14,7 +14,7 @@ public class TransferContractImpl implements EventProcessingAware, TransferContr
 
     @Override
     public String create(String address, String account, long money) {
-        KVDataEntry[] kvDataEntries = eventContext.getLedger().getDataEntries(ledgerHash, address, account);
+        TypedKVEntry[] kvDataEntries = eventContext.getLedger().getDataEntries(ledgerHash, address, account);
         // 肯定有返回值，但若不存在则返回version=-1
         if (kvDataEntries != null && kvDataEntries.length > 0) {
             long currVersion = kvDataEntries[0].getVersion();
@@ -32,13 +32,13 @@ public class TransferContractImpl implements EventProcessingAware, TransferContr
     @Override
     public String transfer(String address, String from, String to, long money) {
         // 首先查询余额
-        KVDataEntry[] kvDataEntries = eventContext.getLedger().getDataEntries(ledgerHash, address, from, to);
+        TypedKVEntry[] kvDataEntries = eventContext.getLedger().getDataEntries(ledgerHash, address, from, to);
         if (kvDataEntries == null || kvDataEntries.length != 2) {
             throw new IllegalStateException(String.format("%s -> %s - %s may be not created !!!", address, from, to));
         } else {
             // 判断from账号中钱数量是否足够
             long fromMoney = 0L, toMoney = 0L, fromVersion = 0L, toVersion = 0L;
-            for (KVDataEntry kvDataEntry : kvDataEntries) {
+            for (TypedKVEntry kvDataEntry : kvDataEntries) {
                 if (kvDataEntry.getKey().equals(from)) {
                     fromMoney = (long) kvDataEntry.getValue();
                     fromVersion = kvDataEntry.getVersion();
@@ -62,7 +62,7 @@ public class TransferContractImpl implements EventProcessingAware, TransferContr
 
     @Override
     public long read(String address, String account) {
-        KVDataEntry[] kvDataEntries = eventContext.getLedger().getDataEntries(ledgerHash, address, account);
+        TypedKVEntry[] kvDataEntries = eventContext.getLedger().getDataEntries(ledgerHash, address, account);
         if (kvDataEntries == null || kvDataEntries.length == 0) {
             return -1;
         }
@@ -71,7 +71,7 @@ public class TransferContractImpl implements EventProcessingAware, TransferContr
 
     @Override
     public String readAll(String address, String account) {
-        KVDataEntry[] kvDataEntries = eventContext.getLedger().getDataEntries(ledgerHash, address, account);
+        TypedKVEntry[] kvDataEntries = eventContext.getLedger().getDataEntries(ledgerHash, address, account);
         // 获取最新的版本号
         if (kvDataEntries == null || kvDataEntries.length == 0) {
             return "";
@@ -91,7 +91,7 @@ public class TransferContractImpl implements EventProcessingAware, TransferContr
 
         KVInfoVO kvInfoVO = new KVInfoVO(kvDataVOS);
 
-        KVDataEntry[] allEntries = eventContext.getLedger().getDataEntries(ledgerHash, address, kvInfoVO);
+        TypedKVEntry[] allEntries = eventContext.getLedger().getDataEntries(ledgerHash, address, kvInfoVO);
 
         return JSON.toJSONString(allEntries);
     }

source/gateway/src/main/java/com/jd/blockchain/gateway/web/BlockBrowserController.java

@@ -25,7 +25,7 @@ import com.jd.blockchain.gateway.PeerService;
 import com.jd.blockchain.gateway.service.DataRetrievalService;
 import com.jd.blockchain.ledger.BlockchainIdentity;
 import com.jd.blockchain.ledger.ContractInfo;
-import com.jd.blockchain.ledger.KVDataEntry;
+import com.jd.blockchain.ledger.TypedKVEntry;
 import com.jd.blockchain.ledger.KVInfoVO;
 import com.jd.blockchain.ledger.LedgerAdminInfo;
 import com.jd.blockchain.ledger.LedgerBlock;
@@ -261,7 +261,7 @@ public class BlockBrowserController implements BlockchainExtendQueryService {
 	@RequestMapping(method = { RequestMethod.GET,
 			RequestMethod.POST }, path = "ledgers/{ledgerHash}/accounts/{address}/entries")
 	@Override
-	public KVDataEntry[] getDataEntries(@PathVariable("ledgerHash") HashDigest ledgerHash,
+	public TypedKVEntry[] getDataEntries(@PathVariable("ledgerHash") HashDigest ledgerHash,
 			@PathVariable("address") String address, @RequestParam("keys") String... keys) {
 		return peerService.getQueryService().getDataEntries(ledgerHash, address, keys);
 	}
@@ -269,7 +269,7 @@ public class BlockBrowserController implements BlockchainExtendQueryService {
 	@RequestMapping(method = { RequestMethod.GET,
 			RequestMethod.POST }, path = "ledgers/{ledgerHash}/accounts/{address}/entries-version")
 	@Override
-	public KVDataEntry[] getDataEntries(@PathVariable("ledgerHash") HashDigest ledgerHash,
+	public TypedKVEntry[] getDataEntries(@PathVariable("ledgerHash") HashDigest ledgerHash,
 			@PathVariable("address") String address, @RequestBody KVInfoVO kvInfoVO) {
 		return peerService.getQueryService().getDataEntries(ledgerHash, address, kvInfoVO);
 	}
@@ -277,7 +277,7 @@ public class BlockBrowserController implements BlockchainExtendQueryService {
 	@RequestMapping(method = { RequestMethod.GET,
 			RequestMethod.POST }, path = "ledgers/{ledgerHash}/accounts/address/{address}/entries")
 	@Override
-	public KVDataEntry[] getDataEntries(@PathVariable("ledgerHash") HashDigest ledgerHash,
+	public TypedKVEntry[] getDataEntries(@PathVariable("ledgerHash") HashDigest ledgerHash,
 			@PathVariable("address") String address,
 			@RequestParam(name = "fromIndex", required = false, defaultValue = "0") int fromIndex,
 			@RequestParam(name = "count", required = false, defaultValue = "-1") int count) {

source/ledger/ledger-core/src/main/java/com/jd/blockchain/ledger/core/DataAccount.java

@@ -2,8 +2,8 @@ package com.jd.blockchain.ledger.core;
 
 import com.jd.blockchain.binaryproto.BinaryProtocol;
 import com.jd.blockchain.ledger.BytesValue;
-import com.jd.blockchain.ledger.KVDataEntry;
-import com.jd.blockchain.ledger.KVDataObject;
+import com.jd.blockchain.ledger.TypedKVEntry;
+import com.jd.blockchain.ledger.TypedKVData;
 import com.jd.blockchain.ledger.MerkleProof;
 import com.jd.blockchain.ledger.TypedValue;
 import com.jd.blockchain.utils.Bytes;

source/ledger/ledger-core/src/main/java/com/jd/blockchain/ledger/core/LedgerQueryService.java

@@ -8,8 +8,9 @@ import com.jd.blockchain.crypto.HashDigest;
 import com.jd.blockchain.ledger.BlockchainIdentity;
 import com.jd.blockchain.ledger.BytesValue;
 import com.jd.blockchain.ledger.ContractInfo;
-import com.jd.blockchain.ledger.KVDataEntry;
-import com.jd.blockchain.ledger.KVDataObject;
+import com.jd.blockchain.ledger.TypedKVEntry;
+import com.jd.blockchain.ledger.TypedValue;
+import com.jd.blockchain.ledger.TypedKVData;
 import com.jd.blockchain.ledger.KVDataVO;
 import com.jd.blockchain.ledger.KVInfoVO;
 import com.jd.blockchain.ledger.LedgerAdminInfo;
@@ -22,12 +23,15 @@ import com.jd.blockchain.ledger.ParticipantNode;
 import com.jd.blockchain.ledger.TransactionState;
 import com.jd.blockchain.ledger.UserInfo;
 import com.jd.blockchain.transaction.BlockchainQueryService;
+import com.jd.blockchain.utils.ArrayUtils;
 import com.jd.blockchain.utils.Bytes;
+import com.jd.blockchain.utils.DataEntry;
+import com.jd.blockchain.utils.DataIterator;
 import com.jd.blockchain.utils.QueryUtil;
 
 public class LedgerQueryService implements BlockchainQueryService {
 
-	private static final KVDataEntry[] EMPTY_ENTRIES = new KVDataEntry[0];
+	private static final TypedKVEntry[] EMPTY_ENTRIES = new TypedKVEntry[0];
 
 	private HashDigest[] ledgerHashs;
 
@@ -278,7 +282,7 @@ public class LedgerQueryService implements BlockchainQueryService {
 	}
 
 	@Override
-	public KVDataEntry[] getDataEntries(HashDigest ledgerHash, String address, String... keys) {
+	public TypedKVEntry[] getDataEntries(HashDigest ledgerHash, String address, String... keys) {
 		if (keys == null || keys.length == 0) {
 			return EMPTY_ENTRIES;
 		}
@@ -287,7 +291,8 @@ public class LedgerQueryService implements BlockchainQueryService {
 		DataAccountQuery dataAccountSet = ledger.getDataAccountSet(block);
 		DataAccount dataAccount = dataAccountSet.getAccount(Bytes.fromBase58(address));
 
-		KVDataEntry[] entries = new KVDataEntry[keys.length];
+		
+		TypedKVEntry[] entries = new TypedKVEntry[keys.length];
 		long ver;
 		for (int i = 0; i < entries.length; i++) {
 			final String currKey = keys[i];
@@ -295,17 +300,17 @@ public class LedgerQueryService implements BlockchainQueryService {
 			ver = dataAccount == null ? -1 : dataAccount.getDataset().getVersion(currKey);
 
 			if (ver < 0) {
-				entries[i] = new KVDataObject(currKey, -1, null);
+				entries[i] = new TypedKVData(currKey, -1, null);
 			} else {
 				BytesValue value = dataAccount.getDataset().getValue(currKey, ver);
-				entries[i] = new KVDataObject(currKey, ver, value);
+				entries[i] = new TypedKVData(currKey, ver, value);
 			}
 		}
 
 		return entries;
 	}
 
-	public KVDataEntry[] getDataEntries(HashDigest ledgerHash, String address, KVInfoVO kvInfoVO) {
+	public TypedKVEntry[] getDataEntries(HashDigest ledgerHash, String address, KVInfoVO kvInfoVO) {
 		// parse kvInfoVO;
 		List<String> keyList = new ArrayList<>();
 		List<Long> versionList = new ArrayList<>();
@@ -335,22 +340,22 @@ public class LedgerQueryService implements BlockchainQueryService {
 		DataAccountQuery dataAccountSet = ledger.getDataAccountSet(block);
 		DataAccount dataAccount = dataAccountSet.getAccount(Bytes.fromBase58(address));
 
-		KVDataEntry[] entries = new KVDataEntry[keys.length];
+		TypedKVEntry[] entries = new TypedKVEntry[keys.length];
 		long ver = -1;
 		for (int i = 0; i < entries.length; i++) {
 //			ver = dataAccount.getDataVersion(Bytes.fromString(keys[i]));
 //			dataAccount.getBytes(Bytes.fromString(keys[i]),1);
 			ver = versions[i];
 			if (ver < 0) {
-				entries[i] = new KVDataObject(keys[i], -1, null);
+				entries[i] = new TypedKVData(keys[i], -1, null);
 			} else {
 				if (dataAccount.getDataset().getDataCount() == 0
 						|| dataAccount.getDataset().getValue(keys[i], ver) == null) {
 					// is the address is not exist; the result is null;
-					entries[i] = new KVDataObject(keys[i], -1, null);
+					entries[i] = new TypedKVData(keys[i], -1, null);
 				} else {
 					BytesValue value = dataAccount.getDataset().getValue(keys[i], ver);
-					entries[i] = new KVDataObject(keys[i], ver, value);
+					entries[i] = new TypedKVData(keys[i], ver, value);
 				}
 			}
 		}
@@ -359,14 +364,22 @@ public class LedgerQueryService implements BlockchainQueryService {
 	}
 
 	@Override
-	public KVDataEntry[] getDataEntries(HashDigest ledgerHash, String address, int fromIndex, int count) {
+	public TypedKVEntry[] getDataEntries(HashDigest ledgerHash, String address, int fromIndex, int count) {
 		checkLedgerHash(ledgerHash);
 		LedgerBlock block = ledger.getLatestBlock();
 		DataAccountQuery dataAccountSet = ledger.getDataAccountSet(block);
 		DataAccount dataAccount = dataAccountSet.getAccount(Bytes.fromBase58(address));
 
-		int pages[] = QueryUtil.calFromIndexAndCount(fromIndex, count, (int) dataAccount.getDataset().getDataCount());
-		return dataAccount.getDataset()..getDataEntries(pages[0], pages[1]);
+//		int pages[] = QueryUtil.calFromIndexAndCount(fromIndex, count, (int) dataAccount.getDataset().getDataCount());
+//		return dataAccount.getDataset().getDataEntry(key, version).getDataEntries(pages[0], pages[1]);
+		
+		DataIterator<String, TypedValue> iterator = dataAccount.getDataset().iterator();
+		iterator.skip(fromIndex);
+		DataEntry<String, TypedValue>[] dataEntries = iterator.next(count);
+		
+		TypedKVEntry[] typedKVEntries = ArrayUtils.castTo(dataEntries, TypedKVEntry.class,
+				e -> e == null ? null : new TypedKVData(e.getKey(), e.getVersion(), e.getValue()));
+		return typedKVEntries;
 	}
 
 	@Override

source/ledger/ledger-core/src/main/java/com/jd/blockchain/ledger/core/MerkleAccountSet.java

@@ -136,7 +136,12 @@ public class MerkleAccountSet implements Transactional, MerkleProvable, AccountQ
 	 * @return
 	 */
 	public boolean contains(Bytes address) {
-		long latestVersion = getVersion(address);
+		InnerMerkleAccount acc = latestAccountsCache.get(address);
+		if (acc != null) {
+			// 无论是新注册未提交的，还是缓存已提交的账户实例，都认为是存在；
+			return true;
+		}
+		long latestVersion = merkleDataset.getVersion(address);
 		return latestVersion > -1;
 	}
 

source/ledger/ledger-core/src/main/java/com/jd/blockchain/ledger/core/MerkleDataSet.java

@@ -10,10 +10,12 @@ import com.jd.blockchain.storage.service.ExPolicyKVStorage.ExPolicy;
 import com.jd.blockchain.storage.service.VersioningKVStorage;
 import com.jd.blockchain.storage.service.utils.BufferedKVStorage;
 import com.jd.blockchain.storage.service.utils.VersioningKVData;
+import com.jd.blockchain.utils.ArrayUtils;
 import com.jd.blockchain.utils.Bytes;
-import com.jd.blockchain.utils.Transactional;
 import com.jd.blockchain.utils.DataEntry;
+import com.jd.blockchain.utils.DataIterator;
 import com.jd.blockchain.utils.Dataset;
+import com.jd.blockchain.utils.Transactional;
 import com.jd.blockchain.utils.io.BytesUtils;
 
 /**
@@ -39,6 +41,9 @@ public class MerkleDataSet implements Transactional, MerkleProvable, Dataset<Byt
 	private final Bytes dataKeyPrefix;
 	private final Bytes merkleKeyPrefix;
 
+	@SuppressWarnings("unchecked")
+	private static final DataEntry<Bytes, byte[]>[] EMPTY_ENTRIES = new DataEntry[0];
+
 	private BufferedKVStorage bufferedStorage;
 
 	private VersioningKVStorage valueStorage;
@@ -162,11 +167,16 @@ public class MerkleDataSet implements Transactional, MerkleProvable, Dataset<Byt
 		return merkleTree.getDataCount();
 	}
 
+	/**
+	 * 返回理论上允许的最大数据索引；
+	 * 
+	 * @return
+	 */
 	public long getMaxIndex() {
 		return merkleTree.getMaxSn();
 	}
 
-	public byte[][] getLatestValues(int fromIndex, int count) {
+	public byte[][] getLatestValues(long fromIndex, int count) {
 		if (count > LedgerConsts.MAX_LIST_COUNT) {
 			throw new IllegalArgumentException("Count exceed the upper limit[" + LedgerConsts.MAX_LIST_COUNT + "]!");
 		}
@@ -182,13 +192,16 @@ public class MerkleDataSet implements Transactional, MerkleProvable, Dataset<Byt
 		return values;
 	}
 
-	public DataEntry<Bytes, byte[]>[] getLatestDataEntries(int fromIndex, int count) {
+	public DataEntry<Bytes, byte[]>[] getLatestDataEntries(long fromIndex, int count) {
 		if (count > LedgerConsts.MAX_LIST_COUNT) {
 			throw new IllegalArgumentException("Count exceed the upper limit[" + LedgerConsts.MAX_LIST_COUNT + "]!");
 		}
 		if (fromIndex < 0 || (fromIndex + count) > merkleTree.getDataCount()) {
 			throw new IllegalArgumentException("Index out of bound!");
 		}
+		if (count == 0) {
+			return EMPTY_ENTRIES;
+		}
 		@SuppressWarnings("unchecked")
 		DataEntry<Bytes, byte[]>[] values = new DataEntry[count];
 		byte[] bytesValue;
@@ -201,6 +214,19 @@ public class MerkleDataSet implements Transactional, MerkleProvable, Dataset<Byt
 		return values;
 	}
 
+	public DataEntry<Bytes, byte[]> getLatestDataEntry(long index) {
+		if (index < 0 || index + 1 > merkleTree.getDataCount()) {
+			throw new IllegalArgumentException("Index out of bound!");
+		}
+		byte[] bytesValue;
+		MerkleDataNode dataNode = merkleTree.getData(index);
+		Bytes dataKey = encodeDataKey(dataNode.getKey());
+		bytesValue = valueStorage.get(dataKey, dataNode.getVersion());
+		DataEntry<Bytes, byte[]> entry = new VersioningKVData<Bytes, byte[]>(dataNode.getKey(), dataNode.getVersion(),
+				bytesValue);
+		return entry;
+	}
+
 	/**
 	 * get the data at the specific index;
 	 * 
@@ -505,6 +531,16 @@ public class MerkleDataSet implements Transactional, MerkleProvable, Dataset<Byt
 		return new VersioningKVData<Bytes, byte[]>(key, version, value);
 	}
 
+	@Override
+	public DataIterator<Bytes, byte[]> iterator() {
+		return new AscDataInterator(getDataCount());
+	}
+
+	@Override
+	public DataIterator<Bytes, byte[]> iteratorDesc() {
+		return new DescDataInterator(getDataCount());
+	}
+
 	public MerkleDataEntry getMerkleEntry(Bytes key, long version) {
 		DataEntry<Bytes, byte[]> dataEntry = getDataEntry(key, version);
 		if (dataEntry == null) {
@@ -586,4 +622,119 @@ public class MerkleDataSet implements Transactional, MerkleProvable, Dataset<Byt
 		merkleTree.cancel();
 		snGenerator = new MerkleSequenceSNGenerator(merkleTree);
 	}
+
+	// ----------------------------------------------------------
+
+	private class AscDataInterator implements DataIterator<Bytes, byte[]> {
+
+		private final long total;
+
+		private long cursor = 0;
+
+		public AscDataInterator(long total) {
+			this.total = total;
+		}
+
+		@Override
+		public void skip(long count) {
+			cursor = nextCursor(count);
+		}
+
+		private long nextCursor(long skippingCount) {
+			long c = cursor + skippingCount;
+			return c > total ? total : c;
+		}
+
+		@Override
+		public DataEntry<Bytes, byte[]> next() {
+			if (hasNext()) {
+				DataEntry<Bytes, byte[]> entry = getLatestDataEntry(cursor);
+				cursor = nextCursor(1);
+				return entry;
+			}
+			return null;
+		}
+
+		@Override
+		public DataEntry<Bytes, byte[]>[] next(int count) {
+			if (hasNext()) {
+				long from = cursor;
+				long nextCursor = nextCursor(count);
+				long c = nextCursor - cursor;
+				if (c > LedgerConsts.MAX_LIST_COUNT) {
+					throw new IllegalArgumentException(
+							"Count exceed the upper limit[" + LedgerConsts.MAX_LIST_COUNT + "]!");
+				}
+				DataEntry<Bytes, byte[]>[] entries = getLatestDataEntries(from, (int) c);
+				cursor = nextCursor;
+				return entries;
+			}
+			return EMPTY_ENTRIES;
+		}
+
+		@Override
+		public boolean hasNext() {
+			return cursor < total;
+		}
+
+	}
+
+	private class DescDataInterator implements DataIterator<Bytes, byte[]> {
+
+		private final long total;
+
+		private long cursor;
+
+		public DescDataInterator(long total) {
+			this.total = total;
+			this.cursor = total - 1;
+		}
+
+		@Override
+		public void skip(long count) {
+			cursor = nextCursor(count);
+		}
+
+		private long nextCursor(long skippingCount) {
+			long c = cursor - skippingCount;
+			return c < 0 ? -1 : c;
+		}
+
+		@Override
+		public DataEntry<Bytes, byte[]> next() {
+			if (hasNext()) {
+				DataEntry<Bytes, byte[]> entry = getLatestDataEntry(cursor);
+				cursor = nextCursor(1);
+				return entry;
+			}
+			return null;
+		}
+
+		@Override
+		public DataEntry<Bytes, byte[]>[] next(int count) {
+			if (hasNext()) {
+				long nextCursor = nextCursor(count);
+				long from = nextCursor + 1;
+				long c = cursor - nextCursor;
+				if (c > LedgerConsts.MAX_LIST_COUNT) {
+					throw new IllegalArgumentException(
+							"Count exceed the upper limit[" + LedgerConsts.MAX_LIST_COUNT + "]!");
+				}
+				DataEntry<Bytes, byte[]>[] entries = getLatestDataEntries(from, (int) c);
+				// reverse;
+				ArrayUtils.reverse(entries);
+
+				cursor = nextCursor;
+				return entries;
+			}
+			return EMPTY_ENTRIES;
+		}
+
+		@Override
+		public boolean hasNext() {
+			return cursor < total;
+		}
+
+	}
+
 }

source/ledger/ledger-core/src/main/java/com/jd/blockchain/ledger/core/handles/ContractLedgerContext.java

@@ -10,7 +10,7 @@ import com.jd.blockchain.ledger.BytesValue;
 import com.jd.blockchain.ledger.ContractInfo;
 import com.jd.blockchain.ledger.DataAccountKVSetOperation;
 import com.jd.blockchain.ledger.DataAccountRegisterOperation;
-import com.jd.blockchain.ledger.KVDataEntry;
+import com.jd.blockchain.ledger.TypedKVEntry;
 import com.jd.blockchain.ledger.KVInfoVO;
 import com.jd.blockchain.ledger.LedgerAdminInfo;
 import com.jd.blockchain.ledger.LedgerBlock;
@@ -172,17 +172,17 @@ public class ContractLedgerContext implements LedgerContext {
 	}
 
 	@Override
-	public KVDataEntry[] getDataEntries(HashDigest ledgerHash, String address, String... keys) {
+	public TypedKVEntry[] getDataEntries(HashDigest ledgerHash, String address, String... keys) {
 		return innerQueryService.getDataEntries(ledgerHash, address, keys);
 	}
 
 	@Override
-	public KVDataEntry[] getDataEntries(HashDigest ledgerHash, String address, KVInfoVO kvInfoVO) {
+	public TypedKVEntry[] getDataEntries(HashDigest ledgerHash, String address, KVInfoVO kvInfoVO) {
 		return innerQueryService.getDataEntries(ledgerHash, address, kvInfoVO);
 	}
 
 	@Override
-	public KVDataEntry[] getDataEntries(HashDigest ledgerHash, String address, int fromIndex, int count) {
+	public TypedKVEntry[] getDataEntries(HashDigest ledgerHash, String address, int fromIndex, int count) {
 		return innerQueryService.getDataEntries(ledgerHash, address, fromIndex, count);
 	}
 

source/ledger/ledger-core/src/test/java/test/com/jd/blockchain/ledger/TxTestContractImpl.java

@@ -3,7 +3,7 @@ package test.com.jd.blockchain.ledger;
 import com.jd.blockchain.contract.ContractEventContext;
 import com.jd.blockchain.contract.ContractLifecycleAware;
 import com.jd.blockchain.contract.EventProcessingAware;
-import com.jd.blockchain.ledger.KVDataEntry;
+import com.jd.blockchain.ledger.TypedKVEntry;
 import com.jd.blockchain.utils.Bytes;
 
 public class TxTestContractImpl implements TxTestContract, ContractLifecycleAware, EventProcessingAware {
@@ -16,7 +16,7 @@ public class TxTestContractImpl implements TxTestContract, ContractLifecycleAwar
 
 	@Override
 	public boolean testReadable() {
-		KVDataEntry v1 = eventContext.getLedger().getDataEntries(eventContext.getCurrentLedgerHash(),
+		TypedKVEntry v1 = eventContext.getLedger().getDataEntries(eventContext.getCurrentLedgerHash(),
 				dataAddress.toBase58(), KEY)[0];
 		String text1 = (String) v1.getValue();
 		System.out.printf("k1=%s, version=%s \r\n", text1, v1.getVersion());
@@ -26,7 +26,7 @@ public class TxTestContractImpl implements TxTestContract, ContractLifecycleAwar
 		System.out.printf("new value = %s\r\n", newValue);
 		eventContext.getLedger().dataAccount(dataAddress).setText(KEY, newValue, v1.getVersion());
 
-		KVDataEntry v2 = eventContext.getLedger().getDataEntries(eventContext.getCurrentLedgerHash(),
+		TypedKVEntry v2 = eventContext.getLedger().getDataEntries(eventContext.getCurrentLedgerHash(),
 				dataAddress.toBase58(), KEY)[0];
 		System.out.printf("---- read new value ----\r\nk1=%s, version=%s \r\n", v2.getValue(), v2.getVersion());
 

source/ledger/ledger-core/src/test/java/test/com/jd/blockchain/ledger/core/AccountSetTest.java

@@ -48,7 +48,8 @@ public class AccountSetTest {
 
 		BlockchainKeypair userKey = BlockchainKeyGenerator.getInstance().generate();
 		accset.register(userKey.getAddress(), userKey.getPubKey());
-
+		
+		//尚未提交之前，可以检索到账户的存在，但版本仍然标记为 -1；
 		MerkleAccount userAcc = accset.getAccount(userKey.getAddress());
 		assertNotNull(userAcc);
 		assertTrue(accset.contains(userKey.getAddress()));

source/ledger/ledger-model/src/main/java/com/jd/blockchain/ledger/ContractInfo.java

@@ -6,8 +6,9 @@ import com.jd.blockchain.binaryproto.PrimitiveType;
 import com.jd.blockchain.consts.DataCodes;
 
 @DataContract(code= DataCodes.CONTRACT_ACCOUNT_HEADER)
-public interface ContractInfo extends BlockchainIdentity {
+public interface ContractInfo extends BlockchainIdentity, MerkleSnapshot {
 
     @DataField(order=4, primitiveType= PrimitiveType.BYTES)
     byte[] getChainCode();
+
 }

source/ledger/ledger-model/src/main/java/com/jd/blockchain/ledger/KVDataObject.java

@@ -1,616 +0,0 @@
-package com.jd.blockchain.ledger;
-
-import java.math.BigInteger;
-import java.util.Date;
-
-import com.jd.blockchain.binaryproto.PrimitiveType;
-import com.jd.blockchain.utils.Bytes;
-import com.jd.blockchain.utils.io.ByteArray;
-import com.jd.blockchain.utils.io.BytesUtils;
-
-/**
- * KV数据项；
- * 
- * <p>
- * 
- * {@link KVDataObject} 被设计为只读对象；
- * 
- * @author huanghaiquan
- *
- */
-public class KVDataObject implements KVDataEntry {
-
-	private String key;
-
-	private long version;
-
-	private BytesValue bytesValue;
-
-	public KVDataObject(String key, long version, BytesValue bytesValue) {
-		this.key = key;
-		this.version = version < 0 ? -1 : version;
-		this.bytesValue = bytesValue;
-	}
-
-	/*
-	 * (non-Javadoc)
-	 * 
-	 * @see com.jd.blockchain.ledger.KVDataEntry#getKey()
-	 */
-	@Override
-	public String getKey() {
-		return key;
-	}
-
-	/*
-	 * (non-Javadoc)
-	 * 
-	 * @see com.jd.blockchain.ledger.KVDataEntry#getVersion()
-	 */
-	@Override
-	public long getVersion() {
-		return version;
-	}
-
-	/*
-	 * (non-Javadoc)
-	 * 
-	 * @see com.jd.blockchain.ledger.KVDataEntry#getType()
-	 */
-	@Override
-	public DataType getType() {
-		return bytesValue == null ? DataType.NIL : bytesValue.getType();
-	}
-
-	@Override
-	public Object getValue() {
-		if (bytesValue == null) {
-			return null;
-		}
-
-		switch (getType()) {
-		case NIL:
-			return null;
-		case TEXT:
-			return bytesValue.getBytes().toUTF8String();
-		case BYTES:
-			return ByteArray.toHex(bytesValue.getBytes().toBytes());
-		case INT64:
-			return BytesUtils.toLong(bytesValue.getBytes().toBytes());
-		case JSON:
-			return bytesValue.getBytes().toUTF8String();
-		case XML:
-			return bytesValue.getBytes().toUTF8String();
-
-		default:
-			throw new IllegalStateException("Unsupported value type[" + getType() + "] to resolve!");
-		}
-	}
-
-	/**
-	 * 是否为空值；
-	 * <p>
-	 * 
-	 * 仅当数据类型 {@link #getType()} 为 {@link PrimitiveType#NIL} 时返回 true，其它情况返回 false；
-	 * <p>
-	 * 
-	 * @return
-	 */
-	public boolean isNil() {
-		return bytesValue == null || DataType.NIL == bytesValue.getType();
-	}
-
-	/**
-	 * 字节数组形式的原始内容；
-	 * 
-	 * @return
-	 */
-	Bytes bytesArray() {
-		return bytesValue.getBytes();
-	}
-
-	/**
-	 * 返回 8 位整数值；
-	 * <p>
-	 * 
-	 * 仅当数据类型 {@link #getType()} 为 {@link PrimitiveType#INT8} 有效；
-	 * <p>
-	 * 
-	 * 无效类型将引发 {@link IllegalStateException} 异常；
-	 * 
-	 * @return
-	 */
-	public byte tinyValue() {
-		if (DataType.INT8 == getType()) {
-			return bytesValue.getBytes().toBytes()[0];
-		}
-		throw new IllegalStateException(String.format("Expected type [%s], but [%s]", DataType.INT8, getType()));
-	}
-
-	/**
-	 * 返回 16 位整数值；
-	 * <p>
-	 * 
-	 * 仅当数据类型 {@link #getType()} 为 {@link PrimitiveType#INT16} 有效；
-	 * <p>
-	 * 
-	 * 无效类型将引发 {@link IllegalStateException} 异常；
-	 * 
-	 * @return
-	 */
-	public short shortValue() {
-		if (DataType.INT16 == getType()) {
-			return BytesUtils.toShort(bytesValue.getBytes().toBytes(), 0);
-		}
-		throw new IllegalStateException(String.format("Expected type [%s], but [%s]", DataType.INT16, getType()));
-	}
-
-	/**
-	 * 返回 32 位整数值；
-	 * <p>
-	 * 
-	 * 仅当数据类型 {@link #getType()} 为 {@link PrimitiveType#INT32} 有效；
-	 * <p>
-	 * 
-	 * 无效类型将引发 {@link IllegalStateException} 异常；
-	 * 
-	 * @return
-	 */
-	public int intValue() {
-		if (DataType.INT32 == getType()) {
-			return BytesUtils.toInt(bytesValue.getBytes().toBytes(), 0);
-		}
-		throw new IllegalStateException(String.format("Expected type [%s], but [%s]", DataType.INT32, getType()));
-	}
-
-	/**
-	 * 返回 64 位整数值；
-	 * <p>
-	 * 
-	 * 仅当数据类型 {@link #getType()} 为 {@link PrimitiveType#INT64} 有效；
-	 * <p>
-	 * 
-	 * 无效类型将引发 {@link IllegalStateException} 异常；
-	 * 
-	 * @return
-	 */
-	public long longValue() {
-		if (DataType.INT64 == getType()) {
-			return BytesUtils.toLong(bytesValue.getBytes().toBytes(), 0);
-		}
-		throw new IllegalStateException(String.format("Expected type [%s], but [%s]", DataType.INT64, getType()));
-
-	}
-
-	/**
-	 * 返回大整数值；
-	 * <p>
-	 * 
-	 * 仅当数据类型 {@link #getType()} 为 {@link PrimitiveType#BIG_INT} 有效；
-	 * <p>
-	 * 
-	 * 无效类型将引发 {@link IllegalStateException} 异常；
-	 * 
-	 * @return
-	 */
-	public BigInteger bigIntValue() {
-		if (DataType.BIG_INT == getType()) {
-			return new BigInteger(bytesValue.getBytes().toBytes());
-		}
-		throw new IllegalStateException(
-				String.format("Expected type [%s], but [%s]", DataType.BIG_INT, getType()));
-	}
-
-	/**
-	 * 返回布尔值；
-	 * <p>
-	 * 
-	 * 仅当数据类型 {@link #getType()} 为 {@link PrimitiveType#BIG_INT} 有效；
-	 * <p>
-	 * 
-	 * 无效类型将引发 {@link IllegalStateException} 异常；
-	 * 
-	 * @return
-	 */
-	public boolean boolValue() {
-		if (DataType.BOOLEAN == getType()) {
-			return BytesUtils.toBoolean(bytesValue.getBytes().toBytes()[0]);
-		}
-		throw new IllegalStateException(
-				String.format("Expected type [%s], but [%s]", DataType.BOOLEAN, getType()));
-	}
-
-	/**
-	 * 返回日期时间值；
-	 * <p>
-	 * 
-	 * 仅当数据类型 {@link #getType()} 为 {@link PrimitiveType#TIMESTAMP} 有效；
-	 * <p>
-	 * 
-	 * 无效类型将引发 {@link IllegalStateException} 异常；
-	 * 
-	 * @return
-	 */
-	public Date datetimeValue() {
-		if (DataType.TIMESTAMP == getType()) {
-			long ts = BytesUtils.toLong(bytesValue.getBytes().toBytes());
-			return new Date(ts);
-		}
-		throw new IllegalStateException(
-				String.format("Expected type [%s], but [%s]", DataType.TIMESTAMP, getType()));
-	}
-
-	/**
-	 * 返回大整数值；
-	 * <p>
-	 * 
-	 * 仅当数据类型 {@link #getType()} 为 {@link PrimitiveType#TEXT} /
-	 * {@link PrimitiveType#JSON} / {@link PrimitiveType#XML} 有效；
-	 * <p>
-	 * 
-	 * 无效类型将引发 {@link IllegalStateException} 异常；
-	 * 
-	 * @return
-	 */
-	public String stringValue() {
-		DataType type = getType();
-		if (DataType.TEXT == type || DataType.JSON == type || DataType.XML == type) {
-			return bytesValue.getBytes().toUTF8String();
-		}
-		throw new IllegalStateException(String.format("Expected type [%s] or [%s] or [%s] , but [%s]",
-				PrimitiveType.TEXT, DataType.JSON, DataType.XML, type));
-	}
-
-//	// ----------------
-//	public KVDataEntry nextVersionNil() {
-//		return nilState(key, version + 1);
-//	}
-//
-//	public KVDataEntry nextVersionBoolean(boolean value) {
-//		return booleanState(key, version + 1, value);
-//	}
-//
-//	public KVDataEntry nextVersionTiny(byte value) {
-//		return tinyState(key, version + 1, value);
-//	}
-//
-//	public KVDataEntry nextVersionShort(short value) {
-//		return shortState(key, version + 1, value);
-//	}
-//
-//	public KVDataEntry nextVersionInt(int value) {
-//		return intState(key, version + 1, value);
-//	}
-//
-//	public KVDataEntry nextVersionLong(long value) {
-//		return longState(key, version + 1, value);
-//	}
-//
-//	public KVDataEntry nextVersionDatetime(Date value) {
-//		return datetimeState(key, version + 1, value);
-//	}
-//
-//	public KVDataEntry nextVersionJson(String value) {
-//		return jsonState(key, version + 1, value);
-//	}
-//
-//	public KVDataEntry nextVersionXml(String value) {
-//		return xmlState(key, version + 1, value);
-//	}
-//
-//	public KVDataEntry nextVersionBigInt(BigInteger value) {
-//		return bigIntState(key, version + 1, value);
-//	}
-//
-//	public KVDataEntry nextVersionText(boolean encrypted, String value) {
-//		return textState(key, version + 1, encrypted, value);
-//	}
-//
-//	public KVDataEntry nextVersionBytes(boolean encrypted, byte[] value) {
-//		return bytesState(key, version + 1, encrypted, value);
-//	}
-//
-//	public KVDataEntry nextVersionImage(boolean encrypted, byte[] value) {
-//		return imageState(key, version + 1, encrypted, value);
-//	}
-//
-//	public KVDataEntry nextVersionVideo(boolean encrypted, byte[] value) {
-//		return videoState(key, version + 1, encrypted, value);
-//	}
-//
-//	public KVDataEntry nextVersionLocation(boolean encrypted, byte[] value) {
-//		return locationState(key, version + 1, encrypted, value);
-//	}
-//	// ----------------
-//
-//	public KVDataEntry newNil() {
-//		return nilState(key, version);
-//	}
-//
-//	public KVDataEntry newBoolean(boolean value) {
-//		return booleanState(key, version, value);
-//	}
-//
-//	public KVDataEntry newTiny(byte value) {
-//		return tinyState(key, version, value);
-//	}
-//
-//	public KVDataEntry newShort(short value) {
-//		return shortState(key, version, value);
-//	}
-//
-//	public KVDataEntry newInt(int value) {
-//		return intState(key, version, value);
-//	}
-//
-//	public KVDataObject newLong(long value) {
-//		return longState(key, version, value);
-//	}
-//
-//	public KVDataEntry newDatetime(Date value) {
-//		return datetimeState(key, version, value);
-//	}
-//
-//	public KVDataEntry newJson(String value) {
-//		return jsonState(key, version, value);
-//	}
-//
-//	public KVDataEntry newXml(String value) {
-//		return xmlState(key, version, value);
-//	}
-//
-//	public KVDataEntry newBigInt(BigInteger value) {
-//		return bigIntState(key, version, value);
-//	}
-//
-//	public KVDataEntry newText(boolean encrypted, String value) {
-//		return textState(key, version, encrypted, value);
-//	}
-//
-//	public KVDataEntry newBytes(boolean encrypted, byte[] value) {
-//		return bytesState(key, version, encrypted, value);
-//	}
-//
-//	public KVDataEntry newImage(boolean encrypted, byte[] value) {
-//		return imageState(key, version, encrypted, value);
-//	}
-//
-//	public KVDataEntry newVideo(boolean encrypted, byte[] value) {
-//		return videoState(key, version, encrypted, value);
-//	}
-//
-//	public KVDataEntry newLocation(boolean encrypted, byte[] value) {
-//		return locationState(key, version, encrypted, value);
-//	}
-//
-//	// ----------------
-//
-//	public KVDataEntry newNil(long version) {
-//		return nilState(key, version);
-//	}
-//
-//	public KVDataEntry newBoolean(long version, boolean value) {
-//		return booleanState(key, version, value);
-//	}
-//
-//	public KVDataEntry newTiny(long version, byte value) {
-//		return tinyState(key, version, value);
-//	}
-//
-//	public KVDataEntry newShort(long version, short value) {
-//		return shortState(key, version, value);
-//	}
-//
-//	public KVDataEntry newInt(long version, int value) {
-//		return intState(key, version, value);
-//	}
-//
-//	public KVDataEntry newLong(long version, long value) {
-//		return longState(key, version, value);
-//	}
-//
-//	public KVDataEntry newDatetime(long version, Date value) {
-//		return datetimeState(key, version, value);
-//	}
-//
-//	public KVDataEntry newJson(long version, String value) {
-//		return jsonState(key, version, value);
-//	}
-//
-//	public KVDataEntry newXml(long version, String value) {
-//		return xmlState(key, version, value);
-//	}
-//
-//	public KVDataEntry newBigInt(long version, BigInteger value) {
-//		return bigIntState(key, version, value);
-//	}
-//
-//	public KVDataEntry newText(long version, boolean encrypted, String value) {
-//		return textState(key, version, encrypted, value);
-//	}
-//
-//	public KVDataEntry newBytes(long version, boolean encrypted, byte[] value) {
-//		return bytesState(key, version, encrypted, value);
-//	}
-//
-//	public KVDataEntry newImage(long version, boolean encrypted, byte[] value) {
-//		return imageState(key, version, encrypted, value);
-//	}
-//
-//	public KVDataEntry newVideo(long version, boolean encrypted, byte[] value) {
-//		return videoState(key, version, encrypted, value);
-//	}
-//
-//	public KVDataEntry newLocation(long version, boolean encrypted, byte[] value) {
-//		return locationState(key, version, encrypted, value);
-//	}
-//
-//	// ----------------
-//
-//	public static KVDataEntry booleanState(String key, boolean value) {
-//		return booleanState(key, -1, value);
-//	}
-//
-//	public static KVDataEntry tinyState(String key, byte value) {
-//		return tinyState(key, -1, value);
-//	}
-//
-//	public static KVDataEntry shortState(String key, short value) {
-//		return shortState(key, -1, value);
-//	}
-//
-//	public static KVDataEntry intState(String key, int value) {
-//		return intState(key, -1, value);
-//	}
-//
-//	public static KVDataEntry longState(String key, long value) {
-//		return longState(key, -1, value);
-//	}
-//
-//	public static KVDataEntry datetimeState(String key, Date value) {
-//		return datetimeState(key, -1, value);
-//	}
-//
-//	public static KVDataEntry jsonState(String key, String value) {
-//		return jsonState(key, -1, value);
-//	}
-//
-//	public static KVDataEntry xmlState(String key, String value) {
-//		return xmlState(key, -1, value);
-//	}
-//
-//	public static KVDataEntry bigIntState(String key, BigInteger value) {
-//		return bigIntState(key, -1, value);
-//	}
-//
-//	public static KVDataObject textState(String key, String value) {
-//		return textState(key, -1, false, value);
-//	}
-//
-//	public static KVDataEntry bytesState(String key, byte[] value) {
-//		return bytesState(key, -1, false, value);
-//	}
-//
-//	public static KVDataEntry imageState(String key, byte[] value) {
-//		return imageState(key, -1, false, value);
-//	}
-//
-//	public static KVDataEntry videoState(String key, byte[] value) {
-//		return videoState(key, -1, false, value);
-//	}
-//
-//	public static KVDataEntry locationState(String key, byte[] value) {
-//		return locationState(key, -1, false, value);
-//	}
-//
-//	// ----------------
-//
-//	public static KVDataEntry textState(String key, boolean encrypted, String value) {
-//		return textState(key, -1, encrypted, value);
-//	}
-//
-//	public static KVDataEntry bytesState(String key, boolean encrypted, byte[] value) {
-//		return bytesState(key, -1, encrypted, value);
-//	}
-//
-//	public static KVDataEntry imageState(String key, boolean encrypted, byte[] value) {
-//		return imageState(key, -1, encrypted, value);
-//	}
-//
-//	public static KVDataEntry videoState(String key, boolean encrypted, byte[] value) {
-//		return videoState(key, -1, encrypted, value);
-//	}
-//
-//	public static KVDataEntry locationState(String key, boolean encrypted, byte[] value) {
-//		return locationState(key, -1, encrypted, value);
-//	}
-//
-//	// ----------------------
-//
-//	public static KVDataEntry nilState(String key) {
-//		return new KVDataObject(key, ValueType.NIL, -1, false, BytesUtils.EMPTY_BYTES);
-//	}
-//
-//	public static KVDataEntry nilState(String key, long version) {
-//		return new KVDataObject(key, ValueType.NIL, version, false, BytesUtils.EMPTY_BYTES);
-//	}
-//
-//	public static KVDataEntry booleanState(String key, long version, boolean value) {
-//		byte[] v = { value ? (byte) 1 : (byte) 0 };
-//		return new KVDataObject(key, ValueType.BOOLEAN, version, false, v);
-//	}
-//
-//	public static KVDataEntry tinyState(String key, long version, byte value) {
-//		byte[] v = { value };
-//		return new KVDataObject(key, ValueType.INT8, version, false, v);
-//	}
-//
-//	public static KVDataEntry shortState(String key, long version, short value) {
-//		byte[] v = BytesUtils.toBytes(value);
-//		return new KVDataObject(key, ValueType.INT16, version, false, v);
-//	}
-//
-//	public static KVDataEntry intState(String key, long version, int value) {
-//		byte[] v = BytesUtils.toBytes(value);
-//		return new KVDataObject(key, ValueType.INT32, version, false, v);
-//	}
-//
-//	public static KVDataObject longState(String key, long version, long value) {
-//		byte[] v = BytesUtils.toBytes(value);
-//		return new KVDataObject(key, ValueType.INT64, version, false, v);
-//	}
-//
-//	public static KVDataEntry datetimeState(String key, long version, Date value) {
-//		byte[] v = BytesUtils.toBytes(value.getTime());
-//		return new KVDataObject(key, ValueType.DATETIME, version, false, v);
-//	}
-//
-//	public static KVDataObject textState(String key, long version, boolean encrypted, String value) {
-//		try {
-//			byte[] v = value.getBytes("UTF-8");
-//			return new KVDataObject(key, ValueType.TEXT, version, encrypted, v);
-//		} catch (UnsupportedEncodingException e) {
-//			throw new IllegalStateException(e.getMessage(), e);
-//		}
-//	}
-//
-//	public static KVDataEntry jsonState(String key, long version, String value) {
-//		try {
-//			byte[] v = value.getBytes("UTF-8");
-//			return new KVDataObject(key, ValueType.JSON, version, false, v);
-//		} catch (UnsupportedEncodingException e) {
-//			throw new IllegalStateException(e.getMessage(), e);
-//		}
-//	}
-//
-//	public static KVDataEntry xmlState(String key, long version, String value) {
-//		try {
-//			byte[] v = value.getBytes("UTF-8");
-//			return new KVDataObject(key, ValueType.XML, version, false, v);
-//		} catch (UnsupportedEncodingException e) {
-//			throw new IllegalStateException(e.getMessage(), e);
-//		}
-//	}
-//
-//	public static KVDataEntry bigIntState(String key, long version, BigInteger value) {
-//		byte[] v = value.toByteArray();
-//		return new KVDataObject(key, ValueType.BIG_INT, version, false, v);
-//	}
-//
-//	public static KVDataEntry bytesState(String key, long version, boolean encrypted, byte[] value) {
-//		return new KVDataObject(key, ValueType.BYTES, version, encrypted, value);
-//	}
-//
-//	public static KVDataEntry imageState(String key, long version, boolean encrypted, byte[] value) {
-//		return new KVDataObject(key, ValueType.IMG, version, encrypted, value);
-//	}
-//
-//	public static KVDataEntry videoState(String key, long version, boolean encrypted, byte[] value) {
-//		return new KVDataObject(key, ValueType.VIDEO, version, encrypted, value);
-//	}
-//
-//	public static KVDataEntry locationState(String key, long version, boolean encrypted, byte[] value) {
-//		return new KVDataObject(key, ValueType.LOCATION, version, encrypted, value);
-//	}
-
-}

source/ledger/ledger-model/src/main/java/com/jd/blockchain/ledger/TypedKVData.java

@@ -0,0 +1,78 @@
+package com.jd.blockchain.ledger;
+
+/**
+ * 强类型的“键-值”数据对象；
+ * 
+ * <p>
+ * 
+ * {@link TypedKVData} 被设计为只读对象；
+ * 
+ * @author huanghaiquan
+ *
+ */
+public class TypedKVData implements TypedKVEntry {
+
+	private String key;
+
+	private long version;
+
+	private DataType type;
+
+	private Object value;
+
+	public TypedKVData(String key, long version, DataType type, Object value) {
+		this.key = key;
+		this.version = version;
+		this.type = type;
+		this.value = value;
+	}
+
+	public TypedKVData(String key, long version, BytesValue bytesValue) {
+		this.key = key;
+		this.version = version;
+		TypedValue typedValue;
+		if (bytesValue != null && bytesValue instanceof TypedValue) {
+			typedValue = (TypedValue) bytesValue;
+		} else {
+			typedValue = TypedValue.wrap(bytesValue);
+		}
+		this.type = typedValue.getType();
+		this.value = typedValue.getValue();
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * 
+	 * @see com.jd.blockchain.ledger.KVDataEntry#getKey()
+	 */
+	@Override
+	public String getKey() {
+		return key;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * 
+	 * @see com.jd.blockchain.ledger.KVDataEntry#getVersion()
+	 */
+	@Override
+	public long getVersion() {
+		return version;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * 
+	 * @see com.jd.blockchain.ledger.KVDataEntry#getType()
+	 */
+	@Override
+	public DataType getType() {
+		return type;
+	}
+
+	@Override
+	public Object getValue() {
+		return value;
+	}
+
+}

source/ledger/ledger-model/src/main/java/com/jd/blockchain/ledger/KVDataEntry.java → source/ledger/ledger-model/src/main/java/com/jd/blockchain/ledger/TypedKVEntry.java

@@ -1,6 +1,6 @@
 package com.jd.blockchain.ledger;
 
-public interface KVDataEntry {
+public interface TypedKVEntry {
 
 	/**
 	 * 键名；
@@ -33,4 +33,12 @@ public interface KVDataEntry {
 	 */
 	Object getValue();
 	
+	default long longValue() {
+		if (getType() == DataType.INT64) {
+			Object value = getValue();
+			return value == null ? 0 : (long) value;
+		}
+		throw new IllegalStateException(String.format("Expected type [%s], but [%s]", DataType.INT64, getType()));
+	}
+	
 }

source/ledger/ledger-model/src/main/java/com/jd/blockchain/ledger/TypedValue.java

@@ -16,9 +16,9 @@ import com.jd.blockchain.utils.io.BytesUtils;
  *
  */
 public class TypedValue implements BytesValue {
-	
+
 	public static final BytesValue NIL = new TypedValue();
-	
+
 	private DataType type;
 	private Bytes value;
 
@@ -31,16 +31,19 @@ public class TypedValue implements BytesValue {
 		this.type = type;
 		this.value = bytes;
 	}
-	
+
 	private TypedValue(BytesValue bytesValue) {
-		this.type = bytesValue.getType();
-		this.value = bytesValue.getBytes();
+		if (bytesValue == null) {
+			this.type = DataType.NIL;
+		} else {
+			this.type = bytesValue.getType();
+			this.value = bytesValue.getBytes();
+		}
 	}
-	
+
 	private TypedValue() {
 		this.type = DataType.NIL;
 	}
-	
 
 	@Override
 	public DataType getType() {
@@ -229,8 +232,7 @@ public class TypedValue implements BytesValue {
 		if (DataType.BIG_INT == type) {
 			return toBigInteger();
 		}
-		throw new IllegalStateException(
-				String.format("Type [%s] cannot be convert to BigInteger!", type));
+		throw new IllegalStateException(String.format("Type [%s] cannot be convert to BigInteger!", type));
 	}
 
 	private BigInteger toBigInteger() {
@@ -280,8 +282,7 @@ public class TypedValue implements BytesValue {
 		if (DataType.TIMESTAMP == type) {
 			return toDatetime();
 		}
-		throw new IllegalStateException(
-				String.format("Type [%s] cannot be convert to datetime!", type));
+		throw new IllegalStateException(String.format("Type [%s] cannot be convert to datetime!", type));
 	}
 
 	private Date toDatetime() {
@@ -346,8 +347,7 @@ public class TypedValue implements BytesValue {
 		if (DataType.HASH_DIGEST == type) {
 			return toHashDegist();
 		}
-		throw new IllegalStateException(
-				String.format("Type [%s] cannot be convert to hash digest!", type));
+		throw new IllegalStateException(String.format("Type [%s] cannot be convert to hash digest!", type));
 	}
 
 	private HashDigest toHashDegist() {
@@ -375,14 +375,13 @@ public class TypedValue implements BytesValue {
 		if (DataType.SIGNATURE_DIGEST == type) {
 			return toSignatureDigest();
 		}
-		throw new IllegalStateException(
-				String.format("Type [%s] cannot be convert to signature digest!", type));
+		throw new IllegalStateException(String.format("Type [%s] cannot be convert to signature digest!", type));
 	}
 
 	private SignatureDigest toSignatureDigest() {
 		return new SignatureDigest(toBytesArray());
 	}
-	
+
 	public static TypedValue wrap(BytesValue value) {
 		return new TypedValue(value);
 	}

source/ledger/ledger-model/src/main/java/com/jd/blockchain/transaction/BlockchainQueryService.java

@@ -5,7 +5,7 @@ import org.springframework.cglib.core.Block;
 import com.jd.blockchain.crypto.HashDigest;
 import com.jd.blockchain.ledger.BlockchainIdentity;
 import com.jd.blockchain.ledger.ContractInfo;
-import com.jd.blockchain.ledger.KVDataEntry;
+import com.jd.blockchain.ledger.TypedKVEntry;
 import com.jd.blockchain.ledger.KVInfoVO;
 import com.jd.blockchain.ledger.LedgerAdminInfo;
 import com.jd.blockchain.ledger.LedgerBlock;
@@ -264,9 +264,9 @@ public interface BlockchainQueryService {
 	 * @param keys
 	 * @return
 	 */
-	KVDataEntry[] getDataEntries(HashDigest ledgerHash, String address, String... keys);
+	TypedKVEntry[] getDataEntries(HashDigest ledgerHash, String address, String... keys);
 
-	KVDataEntry[] getDataEntries(HashDigest ledgerHash, String address, KVInfoVO kvInfoVO);
+	TypedKVEntry[] getDataEntries(HashDigest ledgerHash, String address, KVInfoVO kvInfoVO);
 
 	/**
 	 * 返回指定数据账户中KV数据的总数； <br>
@@ -287,7 +287,7 @@ public interface BlockchainQueryService {
 	 *                   如果参数值为 -1，则返回全部的记录；<br>
 	 * @return
 	 */
-	KVDataEntry[] getDataEntries(HashDigest ledgerHash, String address, int fromIndex, int count);
+	TypedKVEntry[] getDataEntries(HashDigest ledgerHash, String address, int fromIndex, int count);
 
 	/**
 	 * 返回合约账户信息；

source/peer/src/main/java/com/jd/blockchain/peer/web/LedgerQueryController.java

@@ -3,7 +3,6 @@ package com.jd.blockchain.peer.web;
 import java.util.ArrayList;
 import java.util.List;
 
-import com.jd.blockchain.ledger.*;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.RequestBody;
@@ -14,6 +13,22 @@ import org.springframework.web.bind.annotation.RestController;
 
 import com.jd.blockchain.contract.ContractException;
 import com.jd.blockchain.crypto.HashDigest;
+import com.jd.blockchain.ledger.BlockchainIdentity;
+import com.jd.blockchain.ledger.BytesValue;
+import com.jd.blockchain.ledger.ContractInfo;
+import com.jd.blockchain.ledger.KVDataVO;
+import com.jd.blockchain.ledger.KVInfoVO;
+import com.jd.blockchain.ledger.LedgerAdminInfo;
+import com.jd.blockchain.ledger.LedgerBlock;
+import com.jd.blockchain.ledger.LedgerInfo;
+import com.jd.blockchain.ledger.LedgerMetadata;
+import com.jd.blockchain.ledger.LedgerTransaction;
+import com.jd.blockchain.ledger.ParticipantNode;
+import com.jd.blockchain.ledger.TransactionState;
+import com.jd.blockchain.ledger.TypedKVData;
+import com.jd.blockchain.ledger.TypedKVEntry;
+import com.jd.blockchain.ledger.TypedValue;
+import com.jd.blockchain.ledger.UserInfo;
 import com.jd.blockchain.ledger.core.ContractAccountQuery;
 import com.jd.blockchain.ledger.core.DataAccount;
 import com.jd.blockchain.ledger.core.DataAccountQuery;
@@ -23,7 +38,10 @@ import com.jd.blockchain.ledger.core.ParticipantCertData;
 import com.jd.blockchain.ledger.core.TransactionQuery;
 import com.jd.blockchain.ledger.core.UserAccountQuery;
 import com.jd.blockchain.transaction.BlockchainQueryService;
+import com.jd.blockchain.utils.ArrayUtils;
 import com.jd.blockchain.utils.Bytes;
+import com.jd.blockchain.utils.DataEntry;
+import com.jd.blockchain.utils.DataIterator;
 import com.jd.blockchain.utils.QueryUtil;
 
 @RestController
@@ -72,7 +90,7 @@ public class LedgerQueryController implements BlockchainQueryService {
 		}
 		return null;
 	}
-	
+
 	@RequestMapping(method = RequestMethod.GET, path = "ledgers/{ledgerHash}/admininfo")
 	@Override
 	public LedgerAdminInfo getLedgerAdminInfo(@PathVariable(name = "ledgerHash") HashDigest ledgerHash) {
@@ -337,7 +355,7 @@ public class LedgerQueryController implements BlockchainQueryService {
 	@RequestMapping(method = { RequestMethod.GET,
 			RequestMethod.POST }, path = "ledgers/{ledgerHash}/accounts/{address}/entries")
 	@Override
-	public KVDataEntry[] getDataEntries(@PathVariable(name = "ledgerHash") HashDigest ledgerHash,
+	public TypedKVEntry[] getDataEntries(@PathVariable(name = "ledgerHash") HashDigest ledgerHash,
 			@PathVariable(name = "address") String address, @RequestParam("keys") String... keys) {
 		if (keys == null || keys.length == 0) {
 			return null;
@@ -347,15 +365,15 @@ public class LedgerQueryController implements BlockchainQueryService {
 		DataAccountQuery dataAccountSet = ledger.getDataAccountSet(block);
 		DataAccount dataAccount = dataAccountSet.getAccount(Bytes.fromBase58(address));
 
-		KVDataEntry[] entries = new KVDataEntry[keys.length];
+		TypedKVEntry[] entries = new TypedKVEntry[keys.length];
 		long ver;
 		for (int i = 0; i < entries.length; i++) {
 			ver = dataAccount.getDataset().getVersion(keys[i]);
 			if (ver < 0) {
-				entries[i] = new KVDataObject(keys[i], -1, null);
+				entries[i] = new TypedKVData(keys[i], -1, null);
 			} else {
 				BytesValue value = dataAccount.getDataset().getValue(keys[i], ver);
-				entries[i] = new KVDataObject(keys[i], ver, value);
+				entries[i] = new TypedKVData(keys[i], ver, value);
 			}
 		}
 
@@ -365,7 +383,7 @@ public class LedgerQueryController implements BlockchainQueryService {
 	@RequestMapping(method = { RequestMethod.GET,
 			RequestMethod.POST }, path = "ledgers/{ledgerHash}/accounts/{address}/entries-version")
 	@Override
-	public KVDataEntry[] getDataEntries(@PathVariable(name = "ledgerHash") HashDigest ledgerHash,
+	public TypedKVEntry[] getDataEntries(@PathVariable(name = "ledgerHash") HashDigest ledgerHash,
 			@PathVariable(name = "address") String address, @RequestBody KVInfoVO kvInfoVO) {
 		// parse kvInfoVO;
 		List<String> keyList = new ArrayList<>();
@@ -396,21 +414,21 @@ public class LedgerQueryController implements BlockchainQueryService {
 		DataAccountQuery dataAccountSet = ledger.getDataAccountSet(block);
 		DataAccount dataAccount = dataAccountSet.getAccount(Bytes.fromBase58(address));
 
-		KVDataEntry[] entries = new KVDataEntry[keys.length];
+		TypedKVEntry[] entries = new TypedKVEntry[keys.length];
 		long ver = -1;
 		for (int i = 0; i < entries.length; i++) {
 //			ver = dataAccount.getDataVersion(Bytes.fromString(keys[i]));
 			ver = versions[i];
 			if (ver < 0) {
-				entries[i] = new KVDataObject(keys[i], -1, null);
+				entries[i] = new TypedKVData(keys[i], -1, null);
 			} else {
 				if (dataAccount.getDataset().getDataCount() == 0
 						|| dataAccount.getDataset().getValue(keys[i], ver) == null) {
 					// is the address is not exist; the result is null;
-					entries[i] = new KVDataObject(keys[i], -1, null);
+					entries[i] = new TypedKVData(keys[i], -1, null);
 				} else {
 					BytesValue value = dataAccount.getDataset().getValue(keys[i], ver);
-					entries[i] = new KVDataObject(keys[i], ver, value);
+					entries[i] = new TypedKVData(keys[i], ver, value);
 				}
 			}
 		}
@@ -421,7 +439,7 @@ public class LedgerQueryController implements BlockchainQueryService {
 	@RequestMapping(method = { RequestMethod.GET,
 			RequestMethod.POST }, path = "ledgers/{ledgerHash}/accounts/address/{address}/entries")
 	@Override
-	public KVDataEntry[] getDataEntries(@PathVariable(name = "ledgerHash") HashDigest ledgerHash,
+	public TypedKVEntry[] getDataEntries(@PathVariable(name = "ledgerHash") HashDigest ledgerHash,
 			@PathVariable(name = "address") String address,
 			@RequestParam(name = "fromIndex", required = false, defaultValue = "0") int fromIndex,
 			@RequestParam(name = "count", required = false, defaultValue = "-1") int count) {
@@ -431,15 +449,21 @@ public class LedgerQueryController implements BlockchainQueryService {
 		DataAccountQuery dataAccountSet = ledger.getDataAccountSet(block);
 		DataAccount dataAccount = dataAccountSet.getAccount(Bytes.fromBase58(address));
 
-		int pages[] = QueryUtil.calFromIndexAndCount(fromIndex, count, (int) dataAccount.getDataset().getDataCount());
-		return dataAccount.getDataEntries(pages[0], pages[1]);
+//		int pages[] = QueryUtil.calFromIndexAndCount(fromIndex, count, (int) dataAccount.getDataset().getDataCount());
+//		return dataAccount.getDataEntries(pages[0], pages[1]);
+
+		DataIterator<String, TypedValue> iterator = dataAccount.getDataset().iterator();
+		iterator.skip(fromIndex);
+		DataEntry<String, TypedValue>[] dataEntries = iterator.next(count);
+		TypedKVEntry[] typedKVEntries = ArrayUtils.castTo(dataEntries, TypedKVEntry.class,
+				e -> e == null ? null : new TypedKVData(e.getKey(), e.getVersion(), e.getValue()));
+		return typedKVEntries;
 	}
 
 	@RequestMapping(method = RequestMethod.GET, path = "ledgers/{ledgerHash}/accounts/address/{address}/entries/count")
 	@Override
 	public long getDataEntriesTotalCount(@PathVariable(name = "ledgerHash") HashDigest ledgerHash,
 			@PathVariable(name = "address") String address) {
-
 		LedgerQuery ledger = ledgerService.getLedger(ledgerHash);
 		LedgerBlock block = ledger.getLatestBlock();
 		DataAccountQuery dataAccountSet = ledger.getDataAccountSet(block);
@@ -451,7 +475,7 @@ public class LedgerQueryController implements BlockchainQueryService {
 	@RequestMapping(method = RequestMethod.GET, path = "ledgers/{ledgerHash}/contracts/address/{address}")
 	@Override
 	public ContractInfo getContract(@PathVariable(name = "ledgerHash") HashDigest ledgerHash,
-									@PathVariable(name = "address") String address) {
+			@PathVariable(name = "address") String address) {
 		LedgerQuery ledger = ledgerService.getLedger(ledgerHash);
 		LedgerBlock block = ledger.getLatestBlock();
 		ContractAccountQuery contractAccountSet = ledger.getContractAccountSet(block);

source/sdk/sdk-base/src/main/java/com/jd/blockchain/sdk/converters/ClientResolveUtil.java

@@ -39,14 +39,14 @@ import com.jd.blockchain.utils.io.BytesUtils;
 
 public class ClientResolveUtil {
 
-	public static KVDataEntry[] read(KVDataEntry[] kvDataEntries) {
+	public static TypedKVEntry[] read(TypedKVEntry[] kvDataEntries) {
 		if (kvDataEntries == null || kvDataEntries.length == 0) {
 			return kvDataEntries;
 		}
-		KVDataEntry[] resolveKvDataEntries = new KVDataEntry[kvDataEntries.length];
+		TypedKVEntry[] resolveKvDataEntries = new TypedKVEntry[kvDataEntries.length];
 		// kvDataEntries是代理对象，需要处理
 		for (int i = 0; i < kvDataEntries.length; i++) {
-			KVDataEntry kvDataEntry = kvDataEntries[i];
+			TypedKVEntry kvDataEntry = kvDataEntries[i];
 			String key = kvDataEntry.getKey();
 			long version = kvDataEntry.getVersion();
 			DataType dataType = kvDataEntry.getType();
@@ -330,7 +330,7 @@ public class ClientResolveUtil {
 
 	}
 
-	public static class KvData implements KVDataEntry {
+	public static class KvData implements TypedKVEntry {
 
 		private String key;
 

source/sdk/sdk-base/src/main/java/com/jd/blockchain/sdk/proxy/BlockchainServiceProxy.java

@@ -3,7 +3,7 @@ package com.jd.blockchain.sdk.proxy;
 import com.jd.blockchain.crypto.HashDigest;
 import com.jd.blockchain.ledger.BlockchainIdentity;
 import com.jd.blockchain.ledger.ContractInfo;
-import com.jd.blockchain.ledger.KVDataEntry;
+import com.jd.blockchain.ledger.TypedKVEntry;
 import com.jd.blockchain.ledger.KVInfoVO;
 import com.jd.blockchain.ledger.LedgerAdminInfo;
 import com.jd.blockchain.ledger.LedgerBlock;
@@ -161,20 +161,20 @@ public abstract class BlockchainServiceProxy implements BlockchainService {
 	}
 
 	@Override
-	public KVDataEntry[] getDataEntries(HashDigest ledgerHash, String address, String... keys) {
-		KVDataEntry[] kvDataEntries = getQueryService(ledgerHash).getDataEntries(ledgerHash, address, keys);
+	public TypedKVEntry[] getDataEntries(HashDigest ledgerHash, String address, String... keys) {
+		TypedKVEntry[] kvDataEntries = getQueryService(ledgerHash).getDataEntries(ledgerHash, address, keys);
 		return ClientResolveUtil.read(kvDataEntries);
 	}
 
 	@Override
-	public KVDataEntry[] getDataEntries(HashDigest ledgerHash, String address, KVInfoVO kvInfoVO) {
-		KVDataEntry[] kvDataEntries = getQueryService(ledgerHash).getDataEntries(ledgerHash, address, kvInfoVO);
+	public TypedKVEntry[] getDataEntries(HashDigest ledgerHash, String address, KVInfoVO kvInfoVO) {
+		TypedKVEntry[] kvDataEntries = getQueryService(ledgerHash).getDataEntries(ledgerHash, address, kvInfoVO);
 		return ClientResolveUtil.read(kvDataEntries);
 	}
 
 	@Override
-	public KVDataEntry[] getDataEntries(HashDigest ledgerHash, String address, int fromIndex, int count) {
-		KVDataEntry[] kvDataEntries = getQueryService(ledgerHash).getDataEntries(ledgerHash, address, fromIndex, count);
+	public TypedKVEntry[] getDataEntries(HashDigest ledgerHash, String address, int fromIndex, int count) {
+		TypedKVEntry[] kvDataEntries = getQueryService(ledgerHash).getDataEntries(ledgerHash, address, fromIndex, count);
 		return ClientResolveUtil.read(kvDataEntries);
 	}
 

source/sdk/sdk-base/src/main/java/com/jd/blockchain/sdk/proxy/HttpBlockchainQueryService.java

@@ -504,13 +504,13 @@ public interface HttpBlockchainQueryService extends BlockchainExtendQueryService
 	 */
 	@HttpAction(method=HttpMethod.POST, path="ledgers/{ledgerHash}/accounts/{address}/entries")
 	@Override
-	KVDataEntry[] getDataEntries(@PathParam(name="ledgerHash", converter=HashDigestToStringConverter.class) HashDigest ledgerHash,
+	TypedKVEntry[] getDataEntries(@PathParam(name="ledgerHash", converter=HashDigestToStringConverter.class) HashDigest ledgerHash,
                                  @PathParam(name="address") String address,
                                  @RequestParam(name="keys", array = true) String... keys);
 
 	@HttpAction(method=HttpMethod.POST, path="ledgers/{ledgerHash}/accounts/{address}/entries-version")
 	@Override
-	KVDataEntry[] getDataEntries(@PathParam(name="ledgerHash", converter=HashDigestToStringConverter.class) HashDigest ledgerHash,
+	TypedKVEntry[] getDataEntries(@PathParam(name="ledgerHash", converter=HashDigestToStringConverter.class) HashDigest ledgerHash,
 								 @PathParam(name="address") String address,
 								 @RequestBody KVInfoVO kvInfoVO);
 
@@ -531,7 +531,7 @@ public interface HttpBlockchainQueryService extends BlockchainExtendQueryService
 	 */
 	@HttpAction(method = HttpMethod.POST, path = "ledgers/{ledgerHash}/accounts/address/{address}/entries")
 	@Override
-	KVDataEntry[] getDataEntries(@PathParam(name = "ledgerHash") HashDigest ledgerHash,
+	TypedKVEntry[] getDataEntries(@PathParam(name = "ledgerHash") HashDigest ledgerHash,
 										@PathParam(name = "address") String address,
 										@RequestParam(name = "fromIndex", required = false) int fromIndex,
 										@RequestParam(name = "count", required = false) int count);

source/sdk/sdk-samples/src/main/java/com/jd/blockchain/contract/samples/AssetContractImpl.java

@@ -9,8 +9,8 @@ import com.jd.blockchain.contract.ContractException;
 import com.jd.blockchain.contract.EventProcessingAware;
 import com.jd.blockchain.crypto.HashDigest;
 import com.jd.blockchain.ledger.BlockchainIdentity;
-import com.jd.blockchain.ledger.KVDataEntry;
-import com.jd.blockchain.ledger.KVDataObject;
+import com.jd.blockchain.ledger.TypedKVEntry;
+import com.jd.blockchain.ledger.TypedKVData;
 import com.jd.blockchain.utils.Bytes;
 
 /**
@@ -47,16 +47,16 @@ public class AssetContractImpl implements EventProcessingAware, AssetContract {
 		}
 
 		// 查询当前值；
-		KVDataEntry[] kvEntries = eventContext.getLedger().getDataEntries(currentLedgerHash(), ASSET_ADDRESS, KEY_TOTAL,
+		TypedKVEntry[] kvEntries = eventContext.getLedger().getDataEntries(currentLedgerHash(), ASSET_ADDRESS, KEY_TOTAL,
 				assetHolderAddress);
 
 		// 计算资产的发行总数；
-		KVDataObject currTotal = (KVDataObject) kvEntries[0];
+		TypedKVData currTotal = (TypedKVData) kvEntries[0];
 		long newTotal = currTotal.longValue() + amount;
 		eventContext.getLedger().dataAccount(ASSET_ADDRESS).setInt64(KEY_TOTAL, newTotal, currTotal.getVersion());
 		
 		// 分配到持有者账户；
-		KVDataObject holderAmount = (KVDataObject) kvEntries[1];
+		TypedKVData holderAmount = (TypedKVData) kvEntries[1];
 		long newHodlerAmount = holderAmount.longValue() + amount;
 		eventContext.getLedger().dataAccount(ASSET_ADDRESS)
 				.setInt64(assetHolderAddress, newHodlerAmount, holderAmount.getVersion()).setText("K2", "info2", -1)
@@ -77,10 +77,10 @@ public class AssetContractImpl implements EventProcessingAware, AssetContract {
 		checkSignerPermission(fromAddress);
 
 		// 查询现有的余额；
-		KVDataEntry[] origBalances = eventContext.getLedger().getDataEntries(currentLedgerHash(), ASSET_ADDRESS,
+		TypedKVEntry[] origBalances = eventContext.getLedger().getDataEntries(currentLedgerHash(), ASSET_ADDRESS,
 				fromAddress, toAddress);
-		KVDataEntry fromBalanceKV = origBalances[0];
-		KVDataEntry toBalanceKV = origBalances[1];
+		TypedKVEntry fromBalanceKV = origBalances[0];
+		TypedKVEntry toBalanceKV = origBalances[1];
 		long fromBalance = fromBalanceKV.getVersion() == -1 ? 0 : (long) fromBalanceKV.getValue();
 		long toBalance = toBalanceKV.getVersion() == -1 ? 0 : (long) toBalanceKV.getValue();
 

source/sdk/sdk-samples/src/main/java/com/jd/blockchain/sdk/samples/SDKDemo_Query.java

@@ -4,7 +4,7 @@ import com.jd.blockchain.crypto.Crypto;
 import com.jd.blockchain.crypto.HashDigest;
 import com.jd.blockchain.ledger.BlockchainKeyGenerator;
 import com.jd.blockchain.ledger.BlockchainKeypair;
-import com.jd.blockchain.ledger.KVDataEntry;
+import com.jd.blockchain.ledger.TypedKVEntry;
 import com.jd.blockchain.ledger.LedgerBlock;
 import com.jd.blockchain.ledger.LedgerTransaction;
 import com.jd.blockchain.ledger.Transaction;
@@ -67,7 +67,7 @@ public class SDKDemo_Query {
 		// 获取数据；
 		String commerceAccount = "GGhhreGeasdfasfUUfehf9932lkae99ds66jf==";
 		String[] objKeys = new String[] { "x001", "x002" };
-		KVDataEntry[] kvData = service.getDataEntries(LEDGER_HASH, commerceAccount, objKeys);
+		TypedKVEntry[] kvData = service.getDataEntries(LEDGER_HASH, commerceAccount, objKeys);
 
 		long payloadVersion = kvData[0].getVersion();
 

source/sdk/sdk-samples/src/main/java/com/jd/blockchain/sdk/samples/SDK_Contract_Demo.java

@@ -6,7 +6,7 @@ import static com.jd.blockchain.transaction.ContractReturnValue.decode;
 import com.jd.blockchain.contract.TransferContract;
 import com.jd.blockchain.ledger.BlockchainKeyGenerator;
 import com.jd.blockchain.ledger.BlockchainKeypair;
-import com.jd.blockchain.ledger.KVDataEntry;
+import com.jd.blockchain.ledger.TypedKVEntry;
 import com.jd.blockchain.ledger.PreparedTransaction;
 import com.jd.blockchain.ledger.TransactionResponse;
 import com.jd.blockchain.ledger.TransactionTemplate;
@@ -106,11 +106,11 @@ public class SDK_Contract_Demo extends SDK_Base_Demo {
 	}
 
 	private long readByKvOperation(String address, String account) {
-		KVDataEntry[] kvDataEntries = blockchainService.getDataEntries(ledgerHash, address, account);
+		TypedKVEntry[] kvDataEntries = blockchainService.getDataEntries(ledgerHash, address, account);
 		if (kvDataEntries == null || kvDataEntries.length == 0) {
 			throw new IllegalStateException(String.format("Ledger %s Service inner Error !!!", ledgerHash.toBase58()));
 		}
-		KVDataEntry kvDataEntry = kvDataEntries[0];
+		TypedKVEntry kvDataEntry = kvDataEntries[0];
 		if (kvDataEntry.getVersion() == -1) {
 			return 0L;
 		}

source/sdk/sdk-samples/src/main/java/com/jd/blockchain/sdk/samples/SDK_Contract_Random_Demo.java

@@ -79,11 +79,11 @@ public class SDK_Contract_Random_Demo extends SDK_Base_Demo {
 	}
 
 	private long readByKvOperation(String address, String account) {
-		KVDataEntry[] kvDataEntries = blockchainService.getDataEntries(ledgerHash, address, account);
+		TypedKVEntry[] kvDataEntries = blockchainService.getDataEntries(ledgerHash, address, account);
 		if (kvDataEntries == null || kvDataEntries.length == 0) {
 			throw new IllegalStateException(String.format("Ledger %s Service inner Error !!!", ledgerHash.toBase58()));
 		}
-		KVDataEntry kvDataEntry = kvDataEntries[0];
+		TypedKVEntry kvDataEntry = kvDataEntries[0];
 		if (kvDataEntry.getVersion() == -1) {
 			return 0L;
 		}

source/sdk/sdk-samples/src/main/java/com/jd/blockchain/sdk/samples/SDK_InsertData_Demo.java

@@ -107,9 +107,9 @@ public class SDK_InsertData_Demo extends SDK_Base_Demo {
 //		KVDataEntry[] kvData = blockchainService.getDataEntries(ledgerHash, commerceAccount, objKeys);
 
 		// 获取数据账户下所有的KV列表
-		KVDataEntry[] kvData = blockchainService.getDataEntries(ledgerHash, commerceAccount, 0, 100);
+		TypedKVEntry[] kvData = blockchainService.getDataEntries(ledgerHash, commerceAccount, 0, 100);
 		if (kvData != null && kvData.length > 0) {
-			for (KVDataEntry kvDatum : kvData) {
+			for (TypedKVEntry kvDatum : kvData) {
 				System.out.println("kvData.key=" + kvDatum.getKey());
 				System.out.println("kvData.version=" + kvDatum.getVersion());
 				System.out.println("kvData.type=" + kvDatum.getType());

source/sdk/sdk-samples/src/test/java/test/com/jd/blockchain/sdk/test/SDK_GateWay_Query_Test_.java

@@ -24,7 +24,7 @@ import com.jd.blockchain.ledger.BlockchainKeyGenerator;
 import com.jd.blockchain.ledger.BlockchainKeypair;
 import com.jd.blockchain.ledger.DigitalSignature;
 import com.jd.blockchain.ledger.EndpointRequest;
-import com.jd.blockchain.ledger.KVDataEntry;
+import com.jd.blockchain.ledger.TypedKVEntry;
 import com.jd.blockchain.ledger.LedgerBlock;
 import com.jd.blockchain.ledger.LedgerInfo;
 import com.jd.blockchain.ledger.LedgerTransaction;
@@ -149,8 +149,8 @@ public class SDK_GateWay_Query_Test_ {
 
 		String commerceAccount = "GGhhreGeasdfasfUUfehf9932lkae99ds66jf==";
 		String[] objKeys = new String[] { "x001", "x002" };
-		KVDataEntry[] kvData = service.getDataEntries(ledgerHash, commerceAccount, objKeys);
-		for (KVDataEntry kvDatum : kvData) {
+		TypedKVEntry[] kvData = service.getDataEntries(ledgerHash, commerceAccount, objKeys);
+		for (TypedKVEntry kvDatum : kvData) {
 			System.out.println("kvData.key=" + kvDatum.getKey());
 			System.out.println("kvData.version=" + kvDatum.getVersion());
 			System.out.println("kvData.value=" + kvDatum.getValue());

source/test/test-integration/src/main/java/test/com/jd/blockchain/intgr/IntegrationTest.java

@@ -26,7 +26,7 @@ import com.jd.blockchain.ledger.BlockchainKeyGenerator;
 import com.jd.blockchain.ledger.BlockchainKeypair;
 import com.jd.blockchain.ledger.BytesValue;
 import com.jd.blockchain.ledger.DataAccountKVSetOperation;
-import com.jd.blockchain.ledger.KVDataEntry;
+import com.jd.blockchain.ledger.TypedKVEntry;
 import com.jd.blockchain.ledger.LedgerBlock;
 import com.jd.blockchain.ledger.LedgerInfo;
 import com.jd.blockchain.ledger.LedgerInitProperties;
@@ -216,8 +216,8 @@ public class IntegrationTest {
 		ledgerOfNode0.retrieveLatestBlock(); // 更新内存
 
 		// 先验证应答
-		KVDataEntry[] kvDataEntries = blockchainService.getDataEntries(ledgerHash, dataAccountAddress, dataKey);
-		for (KVDataEntry kvDataEntry : kvDataEntries) {
+		TypedKVEntry[] kvDataEntries = blockchainService.getDataEntries(ledgerHash, dataAccountAddress, dataKey);
+		for (TypedKVEntry kvDataEntry : kvDataEntries) {
 			String valHexText = (String) kvDataEntry.getValue();
 			byte[] valBytes = HexUtils.decode(valHexText);
 			String valText = new String(valBytes);

source/test/test-integration/src/test/java/test/com/jd/blockchain/intgr/IntegrationBase.java

@@ -286,8 +286,8 @@ public class IntegrationBase {
 		assertEquals(txResp.getContentHash(), transactionHash);
 		assertEquals(txResp.getBlockHash(), ledgerRepository.getLatestBlockHash());
 
-		KVDataEntry[] kvDataEntries = blockchainService.getDataEntries(ledgerHash, daAddress, dataKey);
-		for (KVDataEntry kvDataEntry : kvDataEntries) {
+		TypedKVEntry[] kvDataEntries = blockchainService.getDataEntries(ledgerHash, daAddress, dataKey);
+		for (TypedKVEntry kvDataEntry : kvDataEntries) {
 			assertEquals(dataKey, kvDataEntry.getKey());
 			String valHexText = (String) kvDataEntry.getValue();
 			assertEquals(dataVal, valHexText);

source/test/test-integration/src/test/java/test/com/jd/blockchain/intgr/IntegrationTestAll4Redis.java

@@ -26,7 +26,7 @@ import com.jd.blockchain.ledger.BlockchainKeyGenerator;
 import com.jd.blockchain.ledger.BlockchainKeypair;
 import com.jd.blockchain.ledger.BytesValue;
 import com.jd.blockchain.ledger.DataAccountKVSetOperation;
-import com.jd.blockchain.ledger.KVDataEntry;
+import com.jd.blockchain.ledger.TypedKVEntry;
 import com.jd.blockchain.ledger.LedgerBlock;
 import com.jd.blockchain.ledger.LedgerInfo;
 import com.jd.blockchain.ledger.LedgerInitProperties;
@@ -302,9 +302,9 @@ public class IntegrationTestAll4Redis {
 		assertEquals(txResp.getContentHash(), prepTx.getHash());
 		assertEquals(txResp.getBlockHash(), ledgerRepository.getLatestBlockHash());
 
-		KVDataEntry[] kvDataEntries = blockchainService.getDataEntries(ledgerHash, dataAccountAddress.toString(),
+		TypedKVEntry[] kvDataEntries = blockchainService.getDataEntries(ledgerHash, dataAccountAddress.toString(),
 				dataKey);
-		for (KVDataEntry kvDataEntry : kvDataEntries) {
+		for (TypedKVEntry kvDataEntry : kvDataEntries) {
 			assertEquals(dataKey, kvDataEntry.getKey());
 			String valHexText = (String) kvDataEntry.getValue();
 			byte[] valBytes = HexUtils.decode(valHexText);

source/test/test-integration/src/test/java/test/com/jd/blockchain/intgr/IntegrationTestDataAccount.java

@@ -23,7 +23,7 @@ import com.jd.blockchain.gateway.GatewayConfigProperties.KeyPairConfig;
 import com.jd.blockchain.ledger.BlockchainKeyGenerator;
 import com.jd.blockchain.ledger.BlockchainKeypair;
 import com.jd.blockchain.ledger.DataAccountKVSetOperation;
-import com.jd.blockchain.ledger.KVDataEntry;
+import com.jd.blockchain.ledger.TypedKVEntry;
 import com.jd.blockchain.ledger.LedgerBlock;
 import com.jd.blockchain.ledger.LedgerInitProperties;
 import com.jd.blockchain.ledger.PreparedTransaction;
@@ -214,7 +214,7 @@ public class IntegrationTestDataAccount {
 			e.printStackTrace();
 		}
 
-		KVDataEntry[] kvDataEntries = blockchainService.getDataEntries(ledgerHashs[0], dataAddr.toBase58(), "A", "B",
+		TypedKVEntry[] kvDataEntries = blockchainService.getDataEntries(ledgerHashs[0], dataAddr.toBase58(), "A", "B",
 				"C", "D");
 		for (int i = 0; i < kvDataEntries.length; i++) {
 			Object result = kvDataEntries[i].getValue();

source/utils/utils-common/src/main/java/com/jd/blockchain/utils/ArrayUtils.java

@@ -9,17 +9,29 @@ import java.util.*;
  */
 public abstract class ArrayUtils {
 	private ArrayUtils() {
-		
+
 	}
-	
+
+	public static <T, R> R[] castTo(T[] objs, Class<R> clazz, CastFunction<T, R> cf) {
+		if (objs == null) {
+			return null;
+		}
+		@SuppressWarnings("unchecked")
+		R[] array = (R[]) Array.newInstance(clazz, objs.length);
+		for (int i = 0; i < objs.length; i++) {
+			array[i] = cf.cast(objs[i]);
+		}
+		return array;
+	}
+
 	public static <T> T[] singleton(T obj, Class<T> clazz) {
 		@SuppressWarnings("unchecked")
 		T[] array = (T[]) Array.newInstance(clazz, 1);
 		array[0] = obj;
 		return array;
 	}
-	
-	public static <T> T[] toArray(Iterator<T> itr, Class<T> clazz){
+
+	public static <T> T[] toArray(Iterator<T> itr, Class<T> clazz) {
 		List<T> lst = new LinkedList<T>();
 		while (itr.hasNext()) {
 			T t = (T) itr.next();
@@ -30,19 +42,19 @@ public abstract class ArrayUtils {
 		lst.toArray(array);
 		return array;
 	}
-	
-	public static <T> T[] toArray(Collection<T> collection, Class<T> clazz){
+
+	public static <T> T[] toArray(Collection<T> collection, Class<T> clazz) {
 		@SuppressWarnings("unchecked")
 		T[] array = (T[]) Array.newInstance(clazz, collection.size());
 		collection.toArray(array);
 		return array;
 	}
-	
-	public static <T> List<T> asList(T[] array){
+
+	public static <T> List<T> asList(T[] array) {
 		return asList(array, 0, array.length);
 	}
-	
-	public static <T> Set<T> asSet(T[] array){
+
+	public static <T> Set<T> asSet(T[] array) {
 		if (array == null || array.length == 0) {
 			return Collections.emptySet();
 		}
@@ -52,8 +64,8 @@ public abstract class ArrayUtils {
 		}
 		return set;
 	}
-	
-	public static <T> SortedSet<T> asSortedSet(T[] array){
+
+	public static <T> SortedSet<T> asSortedSet(T[] array) {
 		if (array == null || array.length == 0) {
 			return Collections.emptySortedSet();
 		}
@@ -63,12 +75,12 @@ public abstract class ArrayUtils {
 		}
 		return set;
 	}
-	
-	public static <T> List<T> asList(T[] array, int fromIndex){
+
+	public static <T> List<T> asList(T[] array, int fromIndex) {
 		return asList(array, fromIndex, array.length);
 	}
-	
-	public static <T> List<T> asList(T[] array, int fromIndex, int toIndex){
+
+	public static <T> List<T> asList(T[] array, int fromIndex, int toIndex) {
 		if (toIndex < fromIndex) {
 			throw new IllegalArgumentException("The toIndex less than fromIndex!");
 		}
@@ -78,10 +90,33 @@ public abstract class ArrayUtils {
 		if (toIndex > array.length) {
 			throw new IllegalArgumentException("The toIndex great than the length of array!");
 		}
-		
+
 		if (fromIndex == toIndex) {
 			return Collections.emptyList();
 		}
 		return new ReadonlyArrayListWrapper<T>(array, fromIndex, toIndex);
 	}
+
+	public static interface CastFunction<T, R> {
+		public R cast(T data);
+	}
+
+	/**
+	 * Reverse all elements of the specified array; <br>
+	 * 
+	 * @param <T>
+	 * @param array
+	 */
+	public static <T> void reverse(T[] array) {
+		if (array == null || array.length < 2) {
+			return;
+		}
+		
+		T t;
+		for (int i = 0, j = array.length - 1; i < j; i++, j--) {
+			t = array[i];
+			array[i] = array[j];
+			array[j] = t;
+		}
+	}
 }

source/utils/utils-common/src/main/java/com/jd/blockchain/utils/BaseConstant.java

@@ -1,7 +1,5 @@
 package com.jd.blockchain.utils;
 
-import java.io.File;
-
 /**
  *
  * @author zhaogw

source/utils/utils-common/src/main/java/com/jd/blockchain/utils/DataEntry.java

@@ -1,7 +1,7 @@
 package com.jd.blockchain.utils;
 
 /**
- * 版本化的键值数据项；
+ * Versioning Key-Value data entry；
  * 
  * @author huanghaiquan
  *

source/utils/utils-common/src/main/java/com/jd/blockchain/utils/DataIterator.java

@@ -0,0 +1,21 @@
+package com.jd.blockchain.utils;
+
+/**
+ * 数据迭代器；
+ * 
+ * @author huanghaiquan
+ *
+ * @param <K>
+ * @param <V>
+ */
+public interface DataIterator<K, V> {
+
+	void skip(long count);
+	
+	DataEntry<K, V> next();
+
+	DataEntry<K, V>[] next(int count);
+	
+	boolean hasNext();
+	
+}

source/utils/utils-common/src/main/java/com/jd/blockchain/utils/DataTypeUtils.java

@@ -1,34 +0,0 @@
-package com.jd.blockchain.utils;
-
-import java.lang.reflect.Type;
-import java.util.HashMap;
-import java.util.Map;
-
-import org.springframework.util.TypeUtils;
-
-public abstract class DataTypeUtils {
-	
-	private static Map<Class<?>, Class<?>> wrapperTypes = new HashMap<Class<?>, Class<?>>();
-	
-	static{
-		wrapperTypes.put(long.class, Long.class);
-		wrapperTypes.put(int.class, Integer.class);
-		wrapperTypes.put(char.class, Character.class);
-		wrapperTypes.put(byte.class, Byte.class);
-		wrapperTypes.put(boolean.class, Boolean.class);
-	}
-	
-	public static boolean isAssignable(Type lhsType, Type rhsType) {
-		boolean assignable = TypeUtils.isAssignable(lhsType, rhsType);
-		if (assignable) {
-			return true;
-		}
-		if (lhsType instanceof Class) {
-			Class<?> lhsClass = (Class<?>) lhsType;
-			
-		}
-		
-		return false;
-	}
-	
-}

source/utils/utils-common/src/main/java/com/jd/blockchain/utils/Dataset.java

@@ -1,7 +1,20 @@
 package com.jd.blockchain.utils;
 
+/**
+ * Key-Value data set;
+ * 
+ * @author huanghaiquan
+ *
+ * @param <K>
+ * @param <V>
+ */
 public interface Dataset<K, V> {
-	
+
+	/**
+	 * Total count of data entries;
+	 * 
+	 * @return
+	 */
 	long getDataCount();
 
 	/**
@@ -26,17 +39,6 @@ public interface Dataset<K, V> {
 	 */
 	long setValue(K key, V value, long version);
 
-//	/**
-//	 * Return the specified version's value;<br>
-//	 * 
-//	 * If the key with the specified version doesn't exist, then return null;<br>
-//	 * If the version is specified to -1, then return the latest version's value;
-//	 * 
-//	 * @param key
-//	 * @param version
-//	 */
-//	byte[] getValue(String key, long version);
-
 	/**
 	 * Return the specified version's value;<br>
 	 * 
@@ -48,47 +50,51 @@ public interface Dataset<K, V> {
 	 */
 	V getValue(K key, long version);
 
-//	/**
-//	 * Return the latest version's value;
-//	 * 
-//	 * @param key
-//	 * @return return null if not exist;
-//	 */
-//	byte[] getValue(String key);
-
 	/**
-	 * Return the latest version's value;
+	 * Return the value of the latest version;
 	 * 
 	 * @param key
 	 * @return return null if not exist;
 	 */
 	V getValue(K key);
 
-//	/**
-//	 * Return the latest version entry associated the specified key; If the key
-//	 * doesn't exist, then return -1;
-//	 * 
-//	 * @param key
-//	 * @return
-//	 */
-//	long getVersion(String key);
-
 	/**
-	 * Return the latest version entry associated the specified key; If the key
-	 * doesn't exist, then return -1;
+	 * Return the latest version number of the specified key;
 	 * 
 	 * @param key
-	 * @return
+	 * @return The version number of the specified key; If the key doesn't exist,
+	 *         then return -1;
 	 */
 	long getVersion(K key);
 
 	/**
+	 * Return data entry
 	 * 
 	 * @param key
 	 * @return Null if the key doesn't exist!
 	 */
 	DataEntry<K, V> getDataEntry(K key);
 
+	/**
+	 * 
+	 * @param key
+	 * @param version
+	 * @return
+	 */
 	DataEntry<K, V> getDataEntry(K key, long version);
 
+	/**
+	 * Ascending iterator；
+	 * 
+	 * @return
+	 */
+	DataIterator<K, V> iterator();
+
+	/**
+	 * Descending iterator；
+	 * 
+	 * @return
+	 */
+	DataIterator<K, V> iteratorDesc();
+
 }

source/utils/utils-common/src/main/java/com/jd/blockchain/utils/DatasetHelper.java

@@ -1,8 +1,12 @@
 package com.jd.blockchain.utils;
 
+/**
+ * Helper for {@link Dataset};
+ * 
+ * @author huanghaiquan
+ *
+ */
 public class DatasetHelper {
-	
-	
 
 	public static final TypeMapper<Bytes, String> UTF8_STRING_BYTES_MAPPER = new TypeMapper<Bytes, String>() {
 
@@ -29,7 +33,7 @@ public class DatasetHelper {
 			return Bytes.fromString(t2);
 		}
 	};
-	
+
 	/**
 	 * 适配两个不同类型参数的数据集；
 	 * 
@@ -121,8 +125,8 @@ public class DatasetHelper {
 		T2 decode(T1 t1);
 
 	}
-	
-	private static class EmptyMapper<T> implements TypeMapper<T, T>{
+
+	private static class EmptyMapper<T> implements TypeMapper<T, T> {
 
 		@Override
 		public T encode(T t) {
@@ -133,7 +137,7 @@ public class DatasetHelper {
 		public T decode(T t) {
 			return t;
 		}
-		
+
 	}
 
 	private static class DatasetUpdatingMonitor<K, V> implements Dataset<K, V> {
@@ -186,6 +190,16 @@ public class DatasetHelper {
 			return dataset.getDataEntry(key, version);
 		}
 
+		@Override
+		public DataIterator<K, V> iterator() {
+			return dataset.iterator();
+		}
+
+		@Override
+		public DataIterator<K, V> iteratorDesc() {
+			return dataset.iteratorDesc();
+		}
+
 	}
 
 	/**
@@ -269,6 +283,73 @@ public class DatasetHelper {
 			return new KeyValueEntry<K2, V2>(key, v, entry.getVersion());
 		}
 
+		@Override
+		public DataIterator<K2, V2> iterator() {
+			DataIterator<K1, V1> it = dataset.iterator();
+			return new DataIteratorAdapter<K1, K2, V1, V2>(it, keyMapper, valueMapper);
+		}
+
+		@Override
+		public DataIterator<K2, V2> iteratorDesc() {
+			DataIterator<K1, V1> it = dataset.iteratorDesc();
+			return new DataIteratorAdapter<K1, K2, V1, V2>(it, keyMapper, valueMapper);
+		}
+
+	}
+
+	private static class DataIteratorAdapter<K1, K2, V1, V2> implements DataIterator<K2, V2> {
+
+		private DataIterator<K1, V1> iterator;
+
+		private TypeMapper<K1, K2> keyMapper;
+		private TypeMapper<V1, V2> valueMapper;
+
+		public DataIteratorAdapter(DataIterator<K1, V1> iterator, TypeMapper<K1, K2> keyMapper,
+				TypeMapper<V1, V2> valueMapper) {
+			this.iterator = iterator;
+			this.keyMapper = keyMapper;
+			this.valueMapper = valueMapper;
+		}
+
+		@Override
+		public void skip(long count) {
+			iterator.skip(count);
+		}
+
+		@Override
+		public DataEntry<K2, V2> next() {
+			DataEntry<K1, V1> entry = iterator.next();
+			return cast(entry);
+		}
+
+		private DataEntry<K2, V2> cast(DataEntry<K1, V1> entry) {
+			if (entry == null) {
+				return null;
+			}
+
+			K2 k = keyMapper.decode(entry.getKey());
+			V2 v = valueMapper.decode(entry.getValue());
+			return new KeyValueEntry<K2, V2>(k, v, entry.getVersion());
+		}
+
+		@SuppressWarnings("unchecked")
+		@Override
+		public DataEntry<K2, V2>[] next(int count) {
+			DataEntry<K1, V1>[] entries = iterator.next(count);
+			if (entries == null) {
+				return null;
+			}
+			if (entries.length == 0) {
+				return (DataEntry<K2, V2>[]) entries;
+			}
+			return ArrayUtils.castTo(entries, DataEntry.class, e -> cast(e));
+		}
+
+		@Override
+		public boolean hasNext() {
+			return iterator.hasNext();
+		}
+
 	}
 
 	private static class KeyValueEntry<K, V> implements DataEntry<K, V> {