com.izforge.izpack.util.JarOutputStream Maven / Gradle / Ivy
/*
* $Id: JarOutputStream.java 2163 2008-05-18 13:48:36Z jponge $
* IzPack - Copyright 2001-2008 Julien Ponge, All Rights Reserved.
*
* http://izpack.org/
* http://izpack.codehaus.org/
*
* Copyright 2005 Klaus Bartz
*
* Licensed 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 com.izforge.izpack.util;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.util.jar.JarFile;
import java.util.jar.Manifest;
//import java.util.zip.ZipException;
//The declarations for ZipOutputStreams will be done
//as full qualified to clear at the use point that
//we do not use the standard class else the extended
//from apache.
//import org.apache.tools.zip.ZipOutputStream;
//import org.apache.tools.zip.ZipEntry;
/**
* IzPack will be able to support different compression methods for the
* packs included in the installation jar file.
* For this a jar output stream will be needed with which the info
* data (size, CRC) can be written after the compressed data.
* This is not possible with the standard class
* java.util.jar.JarOutputStream. Therefore we create an own class
* which supports it. Really the hole work will be delegated to the
* ZipOutputStream from the apache team which solves the problem.
*
* @author Klaus Bartz
*/
public class JarOutputStream extends org.apache.tools.zip.ZipOutputStream
{
private static final int JAR_MAGIC = 0xCAFE;
private boolean firstEntry = true;
private boolean preventClose = false;
/**
* Creates a new JarOutputStream with no manifest.
* Using this constructor it will be NOT possible to write
* data with compression format STORED to the stream without
* declare the info data (size, CRC) at putNextEntry.
*
* @param out the actual output stream
* @throws IOException if an I/O error has occurred
*/
public JarOutputStream(OutputStream out) throws IOException
{
super(out);
}
/**
* Creates a new JarOutputStream with the specified
* Manifest. The manifest is written as the first
* entry to the output stream which will be created from the
* file argument.
*
* @param fout the file object with which the output stream
* should be created
* @param man the Manifest
* @throws IOException if an I/O error has occurred
*/
public JarOutputStream(File fout, Manifest man) throws IOException
{
super(fout);
if (man == null)
{
throw new NullPointerException("man");
}
org.apache.tools.zip.ZipEntry e =
new org.apache.tools.zip.ZipEntry(JarFile.MANIFEST_NAME);
putNextEntry(e);
man.write(new BufferedOutputStream(this));
closeEntry();
}
/**
* Creates a new JarOutputStream with no manifest.
* Will use random access if possible.
*
* @param arg0 the file object with which the output stream
* should be created
* @throws java.io.IOException
*/
public JarOutputStream(File arg0) throws IOException
{
super(arg0);
}
/**
* Begins writing a new JAR file entry and positions the stream
* to the start of the entry data. This method will also close
* any previous entry. The default compression method will be
* used if no compression method was specified for the entry.
* The current time will be used if the entry has no set modification
* time.
*
* @param ze the ZIP/JAR entry to be written
* @throws java.util.zip.ZipException if a ZIP error has occurred
* @throws IOException if an I/O error has occurred
*/
public void putNextEntry(org.apache.tools.zip.ZipEntry ze) throws IOException
{
if (firstEntry)
{
// Make sure that extra field data for first JAR
// entry includes JAR magic number id.
byte[] edata = ze.getExtra();
if (edata != null && !hasMagic(edata))
{
// Prepend magic to existing extra data
byte[] tmp = new byte[edata.length + 4];
System.arraycopy(tmp, 4, edata, 0, edata.length);
edata = tmp;
}
else
{
edata = new byte[4];
}
set16(edata, 0, JAR_MAGIC); // extra field id
set16(edata, 2, 0); // extra field size
ze.setExtra(edata);
firstEntry = false;
}
super.putNextEntry(ze);
}
/**
* @return Returns the preventClose.
*/
public boolean isPreventClose()
{
return preventClose;
}
/**
* Determine whether a call of the close method
* will be performed or not. This is a hack for
* FilterOutputStreams like the CBZip2OutputStream
* of apache which calls close of the slave via
* the final method which will be called from
* the garbage collector.
*
* @param preventClose The preventClose to set.
*/
public void setPreventClose(boolean preventClose)
{
this.preventClose = preventClose;
}
/**
* Closes this output stream and releases any system resources
* associated with the stream if isPreventClose is not true.
* Else nothing will be done. This is a hack for
* FilterOutputStreams like the CBZip2OutputStream which
* calls the close method of the slave at finalizing the class
* may be triggert by the GC.
*
* @throws IOException if an I/O error occurs.
*/
public void close() throws IOException
{
if (!isPreventClose())
{
super.close();
}
}
/**
* Closes this output stream and releases any system resources
* associated with the stream also isPreventClose is true.
* This is a hack for FilterOutputStreams like the CBZip2OutputStream which
* calls the close method of the slave at finalizing the class
* may be triggert by the GC.
*
* @throws IOException if an I/O error occurs.
*/
public void closeAlways() throws IOException
{
setPreventClose(false);
close();
}
/*
* Returns true if specified byte array contains the
* jar magic extra field id.
*/
private static boolean hasMagic(byte[] edata)
{
try
{
int i = 0;
while (i < edata.length)
{
if (get16(edata, i) == JAR_MAGIC)
{
return true;
}
i += get16(edata, i + 2) + 4;
}
}
catch (ArrayIndexOutOfBoundsException e)
{
// Invalid extra field data
}
return false;
}
/*
* Fetches unsigned 16-bit value from byte array at specified offset.
* The bytes are assumed to be in Intel (little-endian) byte order.
*/
private static int get16(byte[] b, int off)
{
return (b[off] & 0xff) | ((b[off + 1] & 0xff) << 8);
}
/*
* Sets 16-bit value at specified offset. The bytes are assumed to
* be in Intel (little-endian) byte order.
*/
private static void set16(byte[] b, int off, int value)
{
b[off] = (byte) value;
b[off + 1] = (byte) (value >> 8);
}
}