extract a common base class for resource decorators

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@718542 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/types/resources/ContentTransformingResource.java

@@ -22,8 +22,6 @@ import java.io.IOException;
 import java.io.OutputStream;
 
 import org.apache.tools.ant.BuildException;
-import org.apache.tools.ant.types.Resource;
-import org.apache.tools.ant.types.Reference;
 import org.apache.tools.ant.types.ResourceCollection;
 import org.apache.tools.ant.util.FileUtils;
 
@@ -36,12 +34,10 @@ import org.apache.tools.ant.util.FileUtils;
  *
  * @since Ant 1.8
  */
-public abstract class ContentTransformingResource extends Resource {
+public abstract class ContentTransformingResource extends ResourceDecorator {
 
     private static final int BUFFER_SIZE = 8192;
 
-    private Resource resource;
-
     /** no arg constructor */
     public ContentTransformingResource() {
     }
@@ -51,91 +47,7 @@ public abstract class ContentTransformingResource extends Resource {
      * @param other the resource to wrap.
      */
     public ContentTransformingResource(ResourceCollection other) {
-        addConfigured(other);
-    }
-
-    /**
-     * Sets the resource to wrap using a single-element collection.
-     * @param a the resource to wrap as a single element Resource collection.
-     */
-    public void addConfigured(ResourceCollection a) {
-        checkChildrenAllowed();
-        if (resource != null) {
-            throw new BuildException("you must not specify more than one resource");
-        }
-        if (a.size() != 1) {
-            throw new BuildException("only single argument resource collections are supported");
-        }
-        resource = (Resource) a.iterator().next();
-    }
-
-    /**
-     * Get the name of the resource.
-     * @return the name of the wrapped resource.
-     */
-    public String getName() {
-        return getResource().getName();
-    }
-
-    /**
-     * Overridden, not allowed to set the name of the resource.
-     * @param name not used.
-     * @throws BuildException always.
-     */
-    public void setName(String name) throws BuildException {
-        throw new BuildException("you can't change the name of a " + getDataTypeName());
-    }
-
-    /**
-     * The exists attribute tells whether a file exists.
-     * @return true if this resource exists.
-     */
-    public boolean isExists() {
-        return getResource().isExists();
-    }
-
-    /**
-     * Set the exists attribute.
-     * @param exists if true, this resource exists.
-     */
-    public void setExists(boolean exists) {
-        throw new BuildException("you can't change the exists state of a " + getDataTypeName());
-    }
-
-    /**
-     * Tells the modification time in milliseconds since 01.01.1970 .
-     *
-     * @return 0 if the resource does not exist to mirror the behavior
-     * of {@link java.io.File File}.
-     */
-    public long getLastModified() {
-        return getResource().getLastModified();
-    }
-
-    /**
-     * Override setLastModified.
-     * @param lastmodified not used.
-     * @throws BuildException always.
-     */
-    public void setLastModified(long lastmodified) throws BuildException {
-        throw new BuildException("you can't change the timestamp of a " + getDataTypeName());
-    }
-
-    /**
-     * Tells if the resource is a directory.
-     * @return boolean flag indicating if the resource is a directory.
-     */
-    public boolean isDirectory() {
-        return getResource().isDirectory();
-    }
-
-    /**
-     * Override setDirectory.
-     * @param directory not used.
-     * @throws BuildException always.
-     */
-    public void setDirectory(boolean directory) throws BuildException {
-        throw new BuildException("you can't change the directory state of a " + getDataTypeName());
+        super(other);
     }
 
     /**
@@ -166,40 +78,6 @@ public abstract class ContentTransformingResource extends Resource {
         }
     }
 
-    /**
-     * Override setSize.
-     * @param size not used.
-     * @throws BuildException always.
-     */
-    public void setSize(long size) throws BuildException {
-        throw new BuildException("you can't change the size of a " + getDataTypeName());
-    }
-
-    /**
-     * Delegates to a comparison of names.
-     * @param other the object to compare to.
-     * @return a negative integer, zero, or a positive integer as this Resource
-     *         is less than, equal to, or greater than the specified Resource.
-     */
-    public int compareTo(Object other) {
-        if (other == this) {
-            return 0;
-        }
-        if (other instanceof ContentTransformingResource) {
-            return getResource().compareTo(
-                ((ContentTransformingResource) other).getResource());
-        }
-        return getResource().compareTo(other);
-    }
-
-    /**
-     * Get the hash code for this Resource.
-     * @return hash code as int.
-     */
-    public int hashCode() {
-        return (getClass().hashCode() << 4) | getResource().hashCode();
-    }
-
     /**
      * Get an InputStream for the Resource.
      * @return an InputStream containing this Resource's content.
@@ -232,25 +110,6 @@ public abstract class ContentTransformingResource extends Resource {
         return out;
     }
 
-    /**
-     * Fulfill the ResourceCollection contract.
-     * @return whether this Resource is a FileProvider.
-     */
-    public boolean isFilesystemOnly() {
-        return false;
-    }
-
-    /**
-     * Overrides the base version.
-     * @param r the Reference to set.
-     */
-    public void setRefid(Reference r) {
-        if (resource != null) {
-            throw noChildrenAllowed();
-        }
-        super.setRefid(r);
-    }
-
     /**
      * Suppress FileProvider, re-implement Appendable
      */
@@ -297,14 +156,4 @@ public abstract class ContentTransformingResource extends Resource {
     protected abstract OutputStream wrapStream(OutputStream out)
         throws IOException;
 
-    private Resource getResource() {
-        if (isReference()) {
-            return (Resource) getCheckedRef();
-        }
-        if (resource == null) {
-            throw new BuildException("no resource specified");
-        }
-        return resource;
-    }
-
 }

src/main/org/apache/tools/ant/types/resources/MappedResource.java

@@ -17,10 +17,6 @@
  */
 package org.apache.tools.ant.types.resources;
 
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.OutputStream;
-import org.apache.tools.ant.BuildException;
 import org.apache.tools.ant.types.Reference;
 import org.apache.tools.ant.types.Resource;
 import org.apache.tools.ant.util.FileNameMapper;
@@ -32,131 +28,40 @@ import org.apache.tools.ant.util.FileNameMapper;
  * <p>Strips the FileProvider interface from decorated resources since
  * it may be used to circumvent name mapping.</p>
  *
- * <p>Overwrites all setters to throw exceptions.</p>
- *
  * @since Ant 1.8.0
  */
-public class MappedResource extends Resource {
-    private final Resource wrapped;
+public class MappedResource extends ResourceDecorator {
     private final FileNameMapper mapper;
-    private final boolean isAppendable;
-    private final boolean isTouchable;
-
-    // should only be instantiated via factory, this also means we
-    // don't have to think about being a reference to a different
-    // resource
 
     /**
      * Wraps an existing resource.
      */
     public MappedResource(Resource r, FileNameMapper m) {
-        wrapped = r;
+        super(r);
         mapper = m;
-        isAppendable = wrapped.as(Appendable.class) != null;
-        isTouchable = wrapped.as(Touchable.class) != null;
     }
 
     /**
      * Maps the name.
      */
     public String getName() {
-        String[] mapped = mapper.mapFileName(wrapped.getName());
-        return mapped != null && mapped.length > 0 ? mapped[0] : null;
-    }
-
-    /**
-     * Not supported.
-     */
-    public void setName(String name) {
-        throw new BuildException(new ImmutableResourceException());
-    }
-
-    /**
-     * delegated to the wrapped resource.
-     */
-    public boolean isExists() {
-        return wrapped.isExists();
-    }
-
-    /**
-     * Not supported.
-     */
-    public void setExists(boolean exists) {
-        throw new BuildException(new ImmutableResourceException());
-    }
-
-    /**
-     * delegated to the wrapped resource.
-     */
-    public long getLastModified() {
-        return wrapped.getLastModified();
-    }
-
-    /**
-     * Not supported.
-     */
-    public void setLastModified(long lastmodified) {
-        throw new BuildException(new ImmutableResourceException());
-    }
-
-    /**
-     * delegated to the wrapped resource.
-     */
-    public boolean isDirectory() {
-        return wrapped.isDirectory();
-    }
-
-    /**
-     * Not supported.
-     */
-    public void setDirectory(boolean directory) {
-        throw new BuildException(new ImmutableResourceException());
-    }
-
-    /**
-     * delegated to the wrapped resource.
-     */
-    public long getSize() {
-        return wrapped.getSize();
-    }
-
-    /**
-     * Not supported.
-     */
-    public void setSize(long size) {
-        throw new BuildException(new ImmutableResourceException());
-    }
-
-    /**
-     * delegated to the wrapped resource.
-     */
-    public InputStream getInputStream() throws IOException {
-        return wrapped.getInputStream();
-    }
-
-    /**
-     * delegated to the wrapped resource.
-     */
-    public OutputStream getOutputStream() throws IOException {
-        return wrapped.getOutputStream();
-    }
-
-    /**
-     * delegated to the wrapped resource.
-     */
-    public boolean isFilesystemOnly() {
-        return wrapped.isFilesystemOnly();
-    }
-
-    public String toString() {
-        return "mapped " + wrapped.toString();
+        String name = getResource().getName();
+        if (isReference()) {
+            return name;
+        } else {
+            String[] mapped = mapper.mapFileName(name);
+            return mapped != null && mapped.length > 0 ? mapped[0] : null;
+        }
     }
 
     /**
-     * Not supported.
+     * Not really supported since mapper is never null.
      */
     public void setRefid(Reference r) {
-        throw new UnsupportedOperationException();
+        if (mapper != null) {
+            throw noChildrenAllowed();
+        }
+        super.setRefid(r);
     }
 
     /**
@@ -164,7 +69,7 @@ public class MappedResource extends Resource {
      */
     public Object as(Class clazz) {
         return FileProvider.class.isAssignableFrom(clazz) 
-            ? null : wrapped.as(clazz);
+            ? null : getResource().as(clazz);
     }
 
 }

src/main/org/apache/tools/ant/types/resources/ResourceDecorator.java

@@ -0,0 +1,267 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ */
+package org.apache.tools.ant.types.resources;
+
+import java.io.InputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.util.Stack;
+
+import org.apache.tools.ant.BuildException;
+import org.apache.tools.ant.Project;
+import org.apache.tools.ant.types.Resource;
+import org.apache.tools.ant.types.Reference;
+import org.apache.tools.ant.types.ResourceCollection;
+
+/**
+ * Abstract class that delegates all reading methods of Resource to
+ * its wrapped resource and deals with reference handling.
+ *
+ * <p>Overwrites all setters to throw exceptions.</p>
+ *
+ * @since Ant 1.8.0
+ */
+public abstract class ResourceDecorator extends Resource {
+
+    private Resource resource;
+
+    /** no arg constructor */
+    protected ResourceDecorator() {
+    }
+
+    /**
+     * Constructor with another resource to wrap.
+     * @param other the resource to wrap.
+     */
+    protected ResourceDecorator(ResourceCollection other) {
+        addConfigured(other);
+    }
+
+    /**
+     * Sets the resource to wrap using a single-element collection.
+     * @param a the resource to wrap as a single element Resource collection.
+     */
+    public final void addConfigured(ResourceCollection a) {
+        checkChildrenAllowed();
+        if (resource != null) {
+            throw new BuildException("you must not specify more than one"
+                                     + " resource");
+        }
+        if (a.size() != 1) {
+            throw new BuildException("only single argument resource collections"
+                                     + " are supported");
+        }
+        resource = (Resource) a.iterator().next();
+    }
+
+    /**
+     * Get the name of the resource.
+     * @return the name of the wrapped resource.
+     */
+    public String getName() {
+        return getResource().getName();
+    }
+
+    /**
+     * The exists attribute tells whether a file exists.
+     * @return true if this resource exists.
+     */
+    public boolean isExists() {
+        return getResource().isExists();
+    }
+
+    /**
+     * Tells the modification time in milliseconds since 01.01.1970 .
+     *
+     * @return 0 if the resource does not exist to mirror the behavior
+     * of {@link java.io.File File}.
+     */
+    public long getLastModified() {
+        return getResource().getLastModified();
+    }
+
+    /**
+     * Tells if the resource is a directory.
+     * @return boolean flag indicating if the resource is a directory.
+     */
+    public boolean isDirectory() {
+        return getResource().isDirectory();
+    }
+
+    /**
+     * Get the size of this Resource.
+     * @return the size, as a long, 0 if the Resource does not exist (for
+     *         compatibility with java.io.File), or UNKNOWN_SIZE if not known.
+     */
+    public long getSize() {
+        return getResource().getSize();
+    }
+
+    /**
+     * Get an InputStream for the Resource.
+     * @return an InputStream containing this Resource's content.
+     * @throws IOException if unable to provide the content of this
+     *         Resource as a stream.
+     * @throws UnsupportedOperationException if InputStreams are not
+     *         supported for this Resource type.
+     */
+    public InputStream getInputStream() throws IOException {
+        return getResource().getInputStream();
+    }
+
+    /**
+     * Get an OutputStream for the Resource.
+     * @return an OutputStream to which content can be written.
+     * @throws IOException if unable to provide the content of this
+     *         Resource as a stream.
+     * @throws UnsupportedOperationException if OutputStreams are not
+     *         supported for this Resource type.
+     */
+    public OutputStream getOutputStream() throws IOException {
+        return getResource().getOutputStream();
+    }
+
+    /**
+     * Fulfill the ResourceCollection contract.
+     * @return whether this Resource is a FileProvider.
+     */
+    public boolean isFilesystemOnly() {
+        return as(FileProvider.class) != null;
+    }
+
+    /**
+     * Overrides the base version.
+     * @param r the Reference to set.
+     */
+    public void setRefid(Reference r) {
+        if (resource != null) {
+            throw noChildrenAllowed();
+        }
+        super.setRefid(r);
+    }
+
+    public Object as(Class clazz) {
+        return getResource().as(clazz);
+    }
+
+    /**
+     * Delegates to a comparison of names.
+     * @param other the object to compare to.
+     * @return a negative integer, zero, or a positive integer as this Resource
+     *         is less than, equal to, or greater than the specified Resource.
+     */
+    public int compareTo(Object other) {
+        if (other == this) {
+            return 0;
+        }
+        if (other instanceof ResourceDecorator) {
+            return getResource().compareTo(
+                ((ResourceDecorator) other).getResource());
+        }
+        return getResource().compareTo(other);
+    }
+
+    /**
+     * Get the hash code for this Resource.
+     * @return hash code as int.
+     */
+    public int hashCode() {
+        return (getClass().hashCode() << 4) | getResource().hashCode();
+    }
+
+    /**
+     * De-references refids if any, ensures a wrapped resource has
+     * been specified.
+     */
+    protected final Resource getResource() {
+        if (isReference()) {
+            return (Resource) getCheckedRef();
+        }
+        if (resource == null) {
+            throw new BuildException("no resource specified");
+        }
+        return resource;
+    }
+
+    protected void dieOnCircularReference(final Stack stack,
+                                          final Project project)
+        throws BuildException {
+        if (isChecked()) {
+            return;
+        }
+        if (isReference()) {
+            super.dieOnCircularReference(stack, project);
+        } else {
+            stack.push(resource);
+            invokeCircularReferenceCheck(resource, stack, project);
+            stack.pop();
+            setChecked(true);
+        }
+    }
+
+    // disable modification
+
+    /**
+     * Overridden, not allowed to set the name of the resource.
+     * @param name not used.
+     * @throws BuildException always.
+     */
+    public void setName(String name) throws BuildException {
+        throw new BuildException("you can't change the name of a "
+                                 + getDataTypeName());
+    }
+
+    /**
+     * Set the exists attribute.
+     * @param exists if true, this resource exists.
+     */
+    public void setExists(boolean exists) {
+        throw new BuildException("you can't change the exists state of a "
+                                 + getDataTypeName());
+    }
+
+    /**
+     * Override setLastModified.
+     * @param lastmodified not used.
+     * @throws BuildException always.
+     */
+    public void setLastModified(long lastmodified) throws BuildException {
+        throw new BuildException("you can't change the timestamp of a "
+                                 + getDataTypeName());
+    }
+
+    /**
+     * Override setDirectory.
+     * @param directory not used.
+     * @throws BuildException always.
+     */
+    public void setDirectory(boolean directory) throws BuildException {
+        throw new BuildException("you can't change the directory state of a "
+                                 + getDataTypeName());
+    }
+
+    /**
+     * Override setSize.
+     * @param size not used.
+     * @throws BuildException always.
+     */
+    public void setSize(long size) throws BuildException {
+        throw new BuildException("you can't change the size of a "
+                                 + getDataTypeName());
+    }
+}