at.spardat.xma.xdelta.JarDelta Maven / Gradle / Ivy
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/*
* Copyright (c) 2003, 2007 s IT Solutions AT Spardat GmbH.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*
*/
package at.spardat.xma.xdelta;
import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.util.Enumeration;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;
import java.util.zip.ZipOutputStream;
import com.nothome.delta.Delta;
import com.nothome.delta.DiffWriter;
import com.nothome.delta.GDiffWriter;
/**
* This class calculates the binary difference of two zip files by applying {@link com.nothome.delta.Delta}
* to all files contained in both zip files. All these binary differences are stored in the output zip file.
* New files are simply copied to the output zip file. Additionally all files contained in the target zip
* file are listed in META-INF/file.list.
* Use {@link JarPatcher} to apply the output zip file.
*
* @author gruber
*/
public class JarDelta {
/**
* Computes the binary differences of two zip files. For all files contained in source and target which
* are not equal, the binary difference is caluclated by using
* {@link com.nothome.delta.Delta#computeDelta(com.nothome.delta.SeekableSource, InputStream, int, DiffWriter)}.
* If the files are equal, nothing is written to the output for them.
* Files contained only in target and files to small for {@link com.nothome.delta.Delta} are copied to output.
* Files contained only in source are ignored.
* At last a list of all files contained in target is written to META-INF/file.list in output.
*
* @param source the original zip file
* @param target a modification of the original zip file
* @param output the zip file where the patches have to be written to
* @throws IOException if an error occures reading or writing any entry in a zip file
*/
public void computeDelta(ZipFile source, ZipFile target, ZipOutputStream output) throws IOException {
try {
ByteArrayOutputStream listBytes = new ByteArrayOutputStream();
PrintWriter list = new PrintWriter(new OutputStreamWriter(listBytes));
for(Enumeration enumer=target.entries();enumer.hasMoreElements();) {
ZipEntry targetEntry = (ZipEntry)enumer.nextElement();
ZipEntry sourceEntry = source.getEntry(targetEntry.getName());
list.println(targetEntry.getName());
if(targetEntry.isDirectory()) {
if(sourceEntry==null) {
ZipEntry outputEntry = new ZipEntry(targetEntry);
output.putNextEntry(outputEntry);
}
continue;
}
int targetSize = (int)targetEntry.getSize();
byte[] targetBytes = new byte[targetSize];
InputStream targetStream = target.getInputStream(targetEntry);
for(int erg=targetStream.read(targetBytes);erg
* usage JarDelta source target output
*/
public static void main(String[] args) throws IOException {
if (args.length != 3) {
System.err.println("usage JarDelta source target output");
return;
}
new JarDelta().computeDelta(new ZipFile(args[0]),new ZipFile(args[1]),new ZipOutputStream(new FileOutputStream(args[2])));
}
}