Finish implementation of ZipFile, use it in Expand (AKA <unzip>).

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@274743 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/taskdefs/Expand.java

@@ -56,16 +56,13 @@ package org.apache.tools.ant.taskdefs;
 
 import java.io.File;
 import java.io.FileInputStream;
-import java.io.RandomAccessFile;
 import java.io.FileOutputStream;
 import java.io.FileNotFoundException;
 import java.io.InputStream;
 import java.io.IOException;
-import java.util.Arrays;
 import java.util.Date;
+import java.util.Enumeration;
 import java.util.Vector;
-import java.util.zip.ZipInputStream;
-import java.util.zip.ZipEntry;
 import org.apache.tools.ant.BuildException;
 import org.apache.tools.ant.DirectoryScanner;
 import org.apache.tools.ant.Project;
@@ -74,6 +71,8 @@ import org.apache.tools.ant.types.FileSet;
 import org.apache.tools.ant.types.PatternSet;
 import org.apache.tools.ant.types.selectors.SelectorUtils;
 import org.apache.tools.ant.util.FileUtils;
+import org.apache.tools.zip.ZipEntry;
+import org.apache.tools.zip.ZipFile;
 
 /**
  * Unzip a file.
@@ -154,37 +153,13 @@ public class Expand extends Task {
      */
     protected void expandFile(FileUtils fileUtils, File srcF, File dir) {
         log("Expanding: " + srcF + " into " + dir, Project.MSG_INFO);
-        ZipInputStream zis = null;
-        FileInputStream fis = null;
-        RandomAccessFile raf = null;
-        byte[] buff = new byte[MARKER_SIZE];
+        ZipFile zf = null;
         try {
-            raf = new RandomAccessFile(srcF, "r");
-            long offset = 0;
-            int more = raf.read(buff);
-            boolean foundMarker = false;
-            while (more != -1 || offset < MAX_LOOKAHEAD) {
-                if (Arrays.equals(buff, ZIPMARKER)) {
-                    foundMarker = true;
-                    break;
-                }
-                raf.seek(++offset);
-                more = raf.read(buff);
-            }
-            raf.close();
-            raf = null;
-
-            fis = new FileInputStream(srcF);
-            if (foundMarker && offset > 0) {
-                log("found a preamble of " + offset 
-                    + " bytes, probably a self-extracting archive");
-                fis.skip(offset);
-            }
-            
-            zis = new ZipInputStream(fis);
-            ZipEntry ze = null;
-            while ((ze = zis.getNextEntry()) != null) {
-                extractFile(fileUtils, srcF, dir, zis,
+            zf = new ZipFile(srcF, "UTF8");
+            Enumeration enum = zf.getEntries();
+            while (enum.hasMoreElements()) {
+                ZipEntry ze = (ZipEntry) enum.nextElement();
+                extractFile(fileUtils, srcF, dir, zf.getInputStream(ze),
                             ze.getName(), new Date(ze.getTime()),
                             ze.isDirectory());
             }
@@ -194,14 +169,9 @@ public class Expand extends Task {
             throw new BuildException("Error while expanding " + srcF.getPath(),
                                      ioe);
         } finally {
-            if (raf != null) {
-                try {
-                    raf.close();
-                } catch (IOException e) {}
-            }
-            if (zis != null) {
+            if (zf != null) {
                 try {
-                    zis.close();
+                    zf.close();
                 } catch (IOException e) {}
             }
         }

src/main/org/apache/tools/zip/ZipFile.java

@@ -63,6 +63,8 @@ import java.util.Calendar;
 import java.util.Date;
 import java.util.Enumeration;
 import java.util.Hashtable;
+import java.util.zip.Inflater;
+import java.util.zip.InflaterInputStream;
 import java.util.zip.ZipException;
 
 /**
@@ -202,7 +204,22 @@ public class ZipFile {
      */
     public InputStream getInputStream(ZipEntry ze)
         throws IOException, ZipException {
-        return null;
+        Long start = (Long) dataOffsets.get(ze);
+        if (start == null) {
+            return null;
+        }
+        BoundedInputStream bis = 
+            new BoundedInputStream(start.longValue(), ze.getCompressedSize());
+        switch (ze.getMethod()) {
+            case ZipEntry.STORED:
+                return bis;
+            case ZipEntry.DEFLATED:
+                bis.addDummy();
+                return new InflaterInputStream(bis, new Inflater(true));
+            default:
+                throw new ZipException("Found unsupported compression method "
+                                       + ze.getMethod());
+        }
     }
 
     private static final int CFH_LEN =
@@ -414,4 +431,72 @@ public class ZipFile {
         }
     }
 
+    /**
+     * InputStream that delegates requests to the underlying
+     * RandomAccessFile, making sure that only bytes from a certain
+     * range can be read.
+     */
+    private class BoundedInputStream extends InputStream {
+        private long start, remaining;
+        private long loc;
+        private boolean addDummyByte = false;
+
+        BoundedInputStream(long start, long remaining) {
+            this.start = start;
+            this.remaining = remaining;
+            loc = start;
+        }
+
+        public int read() throws IOException {
+            if (remaining-- <= 0) {
+                if (addDummyByte) {
+                    addDummyByte = false;
+                    return 0;
+                }
+                return -1;
+            }
+            synchronized (archive) {
+                archive.seek(loc++);
+                return archive.read();
+            }
+        }
+
+        public int read(byte[] b, int off, int len) throws IOException {
+            if (remaining <= 0) {
+                if (addDummyByte) {
+                    addDummyByte = false;
+                    b[off] = 0;
+                    return 1;
+                }
+                return -1;
+            }
+
+            if (len <= 0) {
+                return 0;
+            }
+            
+            if (len > remaining) {
+                len = (int) remaining;
+            }
+            int ret = -1;
+            synchronized (archive) {
+                archive.seek(loc);
+                ret = archive.read(b, off, len);
+            }
+            if (ret > 0) {
+                loc += ret;
+                remaining -= ret;
+            }
+            return ret;
+        }
+
+        /**
+         * Inflater needs an extra dummy byte for nowrap - see
+         * Inflater's javadocs.
+         */
+        void addDummy() {
+            addDummyByte = true; 
+        }
+    }
+
 }

src/testcases/org/apache/tools/ant/taskdefs/UnzipTest.java

@@ -138,9 +138,7 @@ public class UnzipTest extends BuildFileTest {
      * PR 16213
      */
     public void testSelfExtractingArchive() {
-        expectLogContaining("selfExtractingArchive",
-                            "found a preamble of 38439 bytes, "
-                            + "probably a self-extracting archive");
+        executeTarget("selfExtractingArchive");
     }