com.lowagie.text.pdf.MappedRandomAccessFile Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of itext2 Show documentation
Show all versions of itext2 Show documentation
Itext is a java library to create and manipulate PDFs.
This is a fork of version 2.1.7 the last MPL/LGPL version.
It's focused basically on mantain compatibility with newer bouncycastle releases and small bugfixes.
/*
* $Id: MappedRandomAccessFile.java 3314 2008-05-01 23:48:39Z xlv $
*
* Copyright 2006 Joakim Sandstroem
*
* The contents of this file are subject to the Mozilla Public License Version 1.1
* (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.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the License.
*
* The Original Code is 'iText, a free JAVA-PDF library'.
*
* The Initial Developer of the Original Code is Bruno Lowagie. Portions created by
* the Initial Developer are Copyright (C) 1999, 2000, 2001, 2002 by Bruno Lowagie.
* All Rights Reserved.
* Co-Developer of the code is Paulo Soares. Portions created by the Co-Developer
* are Copyright (C) 2000, 2001, 2002 by Paulo Soares. All Rights Reserved.
*
* Contributor(s): all the names of the contributors are added in the source code
* where applicable.
*
* Alternatively, the contents of this file may be used under the terms of the
* LGPL license (the "GNU LIBRARY GENERAL PUBLIC LICENSE"), in which case the
* provisions of LGPL are applicable instead of those above. If you wish to
* allow use of your version of this file only under the terms of the LGPL
* License and not to allow others to use your version of this file under
* the MPL, indicate your decision by deleting the provisions above and
* replace them with the notice and other provisions required by the LGPL.
* If you do not delete the provisions above, a recipient may use your version
* of this file under either the MPL or the GNU LIBRARY GENERAL PUBLIC LICENSE.
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the MPL as stated above or under the terms of the GNU
* Library General Public License as published by the Free Software Foundation;
* either version 2 of the License, or any later version.
*
* This library is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU Library general Public License for more
* details.
*
* If you didn't download this code from the following link, you should check if
* you aren't using an obsolete version:
* http://www.lowagie.com/iText/
*/
package com.lowagie.text.pdf;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.nio.BufferUnderflowException;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
import java.security.AccessController;
import java.security.PrivilegedAction;
/**
* A {@link java.nio.MappedByteBuffer} wrapped as a {@link java.io.RandomAccessFile}
*
* @author Joakim Sandstroem
* Created on 6.9.2006
*/
public class MappedRandomAccessFile {
private MappedByteBuffer mappedByteBuffer = null;
private FileChannel channel = null;
/**
* Constructs a new MappedRandomAccessFile instance
* @param filename String
* @param mode String r, w or rw
* @throws FileNotFoundException
* @throws IOException
*/
public MappedRandomAccessFile(String filename, String mode)
throws FileNotFoundException, IOException {
if (mode.equals("rw"))
init(
new java.io.RandomAccessFile(filename, mode).getChannel(),
FileChannel.MapMode.READ_WRITE);
else
init(
new FileInputStream(filename).getChannel(),
FileChannel.MapMode.READ_ONLY);
}
/**
* initializes the channel and mapped bytebuffer
* @param channel FileChannel
* @param mapMode FileChannel.MapMode
* @throws IOException
*/
private void init(FileChannel channel, FileChannel.MapMode mapMode)
throws IOException {
this.channel = channel;
this.mappedByteBuffer = channel.map(mapMode, 0L, channel.size());
mappedByteBuffer.load();
}
/**
* @since 2.0.8
*/
public FileChannel getChannel() {
return channel;
}
/**
* @see java.io.RandomAccessFile#read()
* @return int next integer or -1 on EOF
*/
public int read() {
try {
byte b = mappedByteBuffer.get();
int n = b & 0xff;
return n;
} catch (BufferUnderflowException e) {
return -1; // EOF
}
}
/**
* @see java.io.RandomAccessFile#read(byte[], int, int)
* @param bytes byte[]
* @param off int offset
* @param len int length
* @return int bytes read or -1 on EOF
*/
public int read(byte bytes[], int off, int len) {
int pos = mappedByteBuffer.position();
int limit = mappedByteBuffer.limit();
if (pos == limit)
return -1; // EOF
int newlimit = pos + len - off;
if (newlimit > limit) {
len = limit - pos; // don't read beyond EOF
}
mappedByteBuffer.get(bytes, off, len);
return len;
}
/**
* @see java.io.RandomAccessFile#getFilePointer()
* @return long
*/
public long getFilePointer() {
return mappedByteBuffer.position();
}
/**
* @see java.io.RandomAccessFile#seek(long)
* @param pos long position
*/
public void seek(long pos) {
mappedByteBuffer.position((int) pos);
}
/**
* @see java.io.RandomAccessFile#length()
* @return long length
*/
public long length() {
return mappedByteBuffer.limit();
}
/**
* @see java.io.RandomAccessFile#close()
* Cleans the mapped bytebuffer and closes the channel
*/
public void close() throws IOException {
clean(mappedByteBuffer);
mappedByteBuffer = null;
if (channel != null)
channel.close();
channel = null;
}
/**
* invokes the close method
* @see java.lang.Object#finalize()
*/
protected void finalize() throws Throwable {
close();
super.finalize();
}
/**
* invokes the clean method on the ByteBuffer's cleaner
* @param buffer ByteBuffer
* @return boolean true on success
*/
public static boolean clean(final java.nio.ByteBuffer buffer) {
if (buffer == null || !buffer.isDirect()) {
return false;
}
if (cleanJava9(buffer)) {
return true;
}
return cleanOldsJDK(buffer);
}
private static boolean cleanJava9(final java.nio.ByteBuffer buffer) {
Boolean b = (Boolean) AccessController.doPrivileged(new PrivilegedAction() {
public Boolean run() {
Boolean success = Boolean.FALSE;
try {
final Class unsafeClass = Class.forName("sun.misc.Unsafe");
final Field theUnsafeField = unsafeClass.getDeclaredField("theUnsafe");
theUnsafeField.setAccessible(true);
final Object theUnsafe = theUnsafeField.get(null);
final Method invokeCleanerMethod = unsafeClass.getMethod("invokeCleaner", java.nio.ByteBuffer.class);
invokeCleanerMethod.invoke(theUnsafe, buffer);
success = Boolean.TRUE;
} catch (Exception ignore) {
// Ignore
}
return success;
}
});
return b.booleanValue();
}
private static boolean cleanOldsJDK(final java.nio.ByteBuffer buffer) {
Boolean b = (Boolean) AccessController.doPrivileged(new PrivilegedAction() {
public Boolean run() {
Boolean success = Boolean.FALSE;
try {
Method getCleanerMethod = buffer.getClass().getMethod("cleaner", (Class[])null);
if (!getCleanerMethod.isAccessible()) {
getCleanerMethod.setAccessible(true);
}
Object cleaner = getCleanerMethod.invoke(buffer, (Object[])null);
Method clean = cleaner.getClass().getMethod("clean", (Class[])null);
clean.invoke(cleaner, (Object[])null);
success = Boolean.TRUE;
} catch (Exception e) {
// Ignore
}
return success;
}
});
return b.booleanValue();
}
}