/*
* 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 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;
/**
* A compressed resource.
*
* <p>Wraps around another resource, delegates all queries (except
* getSize) to that other resource but uncompresses/compresses streams
* on the fly.</p>
*
* @since Ant 1.7
*/
public abstract class CompressedResource extends Resource {
private Resource resource;
/** no arg constructor */
public CompressedResource() {
}
/**
* Constructor with another resource to wrap.
* @param other the resource to wrap.
*/
public CompressedResource(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 compressed"
+ " resource");
}
/**
* 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 "
+ " compressed resource");
}
/**
* 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 "
+ " compressed resource");
}
/**
* 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 "
+ " compressed resource");
}
/**
* 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() {
if (isExists()) {
InputStream in = null;
try {
in = getInputStream();
byte[] buf = new byte[8192];
int size = 0;
int readNow;
while ((readNow = in.read(buf, 0, buf.length)) > 0) {
size += readNow;
}
return size;
} catch (IOException ex) {
throw new BuildException("caught exception while reading "
+ getName(), ex);
} finally {
FileUtils.close(in);
}
} else {
return 0;
}
}
/**
* 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 "
+ " compressed resource");
}
/**
* 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 CompressedResource) {
return getResource().compareTo(
((CompressedResource) other).getResource());
}
return getResource().compareTo(other);
}
/**
* Get the hash code for this Resource.
* @return hash code as int.
*/
public int hashCode() {
return getResource().hashCode();
}
/**
* 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 {
InputStream in = getResource().getInputStream();
if (in != null) {
in = wrapStream(in);
}
return in;
}
/**
* 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 {
OutputStream out = getResource().getOutputStream();
if (out != null) {
out = wrapStream(out);
}
return out;
}
/**
* Fulfill the ResourceCollection contract.
* @return whether this Resource is a FileResource.
*/
public boolean isFilesystemOnly() {
return false;
}
/**
* Get the string representation of this Resource.
* @return this Resource formatted as a String.
* @since Ant 1.7
*/
public String toString() {
return getCompressionName() + " compressed "
+ getResource().toString();
}
/**
* Overrides the base version.
* @param r the Reference to set.
*/
public void setRefid(Reference r) {
if (resource != null) {
throw noChildrenAllowed();
}
super.setRefid(r);
}
/**
* Is supposed to wrap the stream to allow decompression on the fly.
*
* @param in InputStream to wrap, will never be null.
* @return a compressed inputstream.
* @throws IOException if there is a problem.
*/
protected abstract InputStream wrapStream(InputStream in)
throws IOException;
/**
* Is supposed to wrap the stream to allow compression on the fly.
*
* @param out OutputStream to wrap, will never be null.
* @return a compressed outputstream.
* @throws IOException if there is a problem.
*/
protected abstract OutputStream wrapStream(OutputStream out)
throws IOException;
/**
* @return the name of the compression method.
*/
protected abstract String getCompressionName();
private Resource getResource() {
if (isReference()) {
return (Resource) getCheckedRef();
} else if (resource == null) {
throw new BuildException("no resource specified");
}
return resource;
}
}
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