org.apache.commons.compress.compressors.pack200.Pack200Utils Maven / Gradle / Ivy
Show all versions of commons-compress Show documentation
/*
* 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.commons.compress.compressors.pack200;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import java.util.jar.JarFile;
import java.util.jar.JarOutputStream;
import java.util.jar.Pack200;
/**
* Utility methods for Pack200.
*
* @ThreadSafe
* @since 1.3
*/
public class Pack200Utils {
private Pack200Utils() { }
/**
* Normalizes a JAR archive in-place so it can be safely signed
* and packed.
*
* As stated in Pack200.Packer's
* javadocs applying a Pack200 compression to a JAR archive will
* in general make its sigantures invalid. In order to prepare a
* JAR for signing it should be "normalized" by packing and
* unpacking it. This is what this method does.
*
* Note this methods implicitly sets the segment length to
* -1.
*
* @param jar the JAR archive to normalize
* @throws IOException if reading or writing fails
*/
public static void normalize(final File jar)
throws IOException {
normalize(jar, jar, null);
}
/**
* Normalizes a JAR archive in-place so it can be safely signed
* and packed.
*
* As stated in Pack200.Packer's
* javadocs applying a Pack200 compression to a JAR archive will
* in general make its sigantures invalid. In order to prepare a
* JAR for signing it should be "normalized" by packing and
* unpacking it. This is what this method does.
*
* @param jar the JAR archive to normalize
* @param props properties to set for the pack operation. This
* method will implicitly set the segment limit to -1.
* @throws IOException if reading or writing fails
*/
public static void normalize(final File jar, final Map props)
throws IOException {
normalize(jar, jar, props);
}
/**
* Normalizes a JAR archive so it can be safely signed and packed.
*
* As stated in Pack200.Packer's
* javadocs applying a Pack200 compression to a JAR archive will
* in general make its sigantures invalid. In order to prepare a
* JAR for signing it should be "normalized" by packing and
* unpacking it. This is what this method does.
*
* This method does not replace the existing archive but creates
* a new one.
*
* Note this methods implicitly sets the segment length to
* -1.
*
* @param from the JAR archive to normalize
* @param to the normalized archive
* @throws IOException if reading or writing fails
*/
public static void normalize(final File from, final File to)
throws IOException {
normalize(from, to, null);
}
/**
* Normalizes a JAR archive so it can be safely signed and packed.
*
* As stated in Pack200.Packer's
* javadocs applying a Pack200 compression to a JAR archive will
* in general make its sigantures invalid. In order to prepare a
* JAR for signing it should be "normalized" by packing and
* unpacking it. This is what this method does.
*
* This method does not replace the existing archive but creates
* a new one.
*
* @param from the JAR archive to normalize
* @param to the normalized archive
* @param props properties to set for the pack operation. This
* method will implicitly set the segment limit to -1.
* @throws IOException if reading or writing fails
*/
public static void normalize(final File from, final File to, Map props)
throws IOException {
if (props == null) {
props = new HashMap<>();
}
props.put(Pack200.Packer.SEGMENT_LIMIT, "-1");
final File tempFile = File.createTempFile("commons-compress", "pack200normalize");
try {
try (FileOutputStream fos = new FileOutputStream(tempFile);
JarFile jarFile = new JarFile(from)) {
final Pack200.Packer packer = Pack200.newPacker();
packer.properties().putAll(props);
packer.pack(jarFile, fos);
}
final Pack200.Unpacker unpacker = Pack200.newUnpacker();
try (JarOutputStream jos = new JarOutputStream(new FileOutputStream(to))) {
unpacker.unpack(tempFile, jos);
}
} finally {
if (!tempFile.delete()) {
tempFile.deleteOnExit();
}
}
}
}