001: /*
002: * $Id: MappedRandomAccessFile.java 2515 2006-12-28 12:52:22Z psoares33 $
003: *
004: * Copyright 2006 Joakim Sandstroem
005: *
006: * The contents of this file are subject to the Mozilla Public License Version 1.1
007: * (the "License"); you may not use this file except in compliance with the License.
008: * You may obtain a copy of the License at http://www.mozilla.org/MPL/
009: *
010: * Software distributed under the License is distributed on an "AS IS" basis,
011: * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
012: * for the specific language governing rights and limitations under the License.
013: *
014: * The Original Code is 'iText, a free JAVA-PDF library'.
015: *
016: * The Initial Developer of the Original Code is Bruno Lowagie. Portions created by
017: * the Initial Developer are Copyright (C) 1999, 2000, 2001, 2002 by Bruno Lowagie.
018: * All Rights Reserved.
019: * Co-Developer of the code is Paulo Soares. Portions created by the Co-Developer
020: * are Copyright (C) 2000, 2001, 2002 by Paulo Soares. All Rights Reserved.
021: *
022: * Contributor(s): all the names of the contributors are added in the source code
023: * where applicable.
024: *
025: * Alternatively, the contents of this file may be used under the terms of the
026: * LGPL license (the "GNU LIBRARY GENERAL PUBLIC LICENSE"), in which case the
027: * provisions of LGPL are applicable instead of those above. If you wish to
028: * allow use of your version of this file only under the terms of the LGPL
029: * License and not to allow others to use your version of this file under
030: * the MPL, indicate your decision by deleting the provisions above and
031: * replace them with the notice and other provisions required by the LGPL.
032: * If you do not delete the provisions above, a recipient may use your version
033: * of this file under either the MPL or the GNU LIBRARY GENERAL PUBLIC LICENSE.
034: *
035: * This library is free software; you can redistribute it and/or modify it
036: * under the terms of the MPL as stated above or under the terms of the GNU
037: * Library General Public License as published by the Free Software Foundation;
038: * either version 2 of the License, or any later version.
039: *
040: * This library is distributed in the hope that it will be useful, but WITHOUT
041: * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
042: * FOR A PARTICULAR PURPOSE. See the GNU Library general Public License for more
043: * details.
044: *
045: * If you didn't download this code from the following link, you should check if
046: * you aren't using an obsolete version:
047: * http://www.lowagie.com/iText/
048: */
049: package com.lowagie.text.pdf;
050:
051: import java.io.FileInputStream;
052: import java.io.FileNotFoundException;
053: import java.io.IOException;
054: import java.lang.reflect.Method;
055: import java.nio.BufferUnderflowException;
056: import java.nio.MappedByteBuffer;
057: import java.nio.channels.FileChannel;
058: import java.security.AccessController;
059: import java.security.PrivilegedAction;
060:
061: /**
062: * A {@link java.nio.MappedByteBuffer} wrapped as a {@link java.io.RandomAccessFile}
063: *
064: * @author Joakim Sandstroem
065: * Created on 6.9.2006
066: */
067: public class MappedRandomAccessFile {
068:
069: private MappedByteBuffer mappedByteBuffer = null;
070: private FileChannel channel = null;
071:
072: /**
073: * Constructs a new MappedRandomAccessFile instance
074: * @param filename String
075: * @param mode String r, w or rw
076: * @throws FileNotFoundException
077: * @throws IOException
078: */
079: public MappedRandomAccessFile(String filename, String mode)
080: throws FileNotFoundException, IOException {
081:
082: if (mode.equals("rw"))
083: init(new java.io.RandomAccessFile(filename, mode)
084: .getChannel(), FileChannel.MapMode.READ_WRITE);
085: else
086: init(new FileInputStream(filename).getChannel(),
087: FileChannel.MapMode.READ_ONLY);
088:
089: }
090:
091: /**
092: * initializes the channel and mapped bytebuffer
093: * @param channel FileChannel
094: * @param mapMode FileChannel.MapMode
095: * @throws IOException
096: */
097: private void init(FileChannel channel, FileChannel.MapMode mapMode)
098: throws IOException {
099:
100: this .channel = channel;
101: this .mappedByteBuffer = channel
102: .map(mapMode, 0L, channel.size());
103: mappedByteBuffer.load();
104: }
105:
106: /**
107: * @see java.io.RandomAccessFile#read()
108: * @return int next integer or -1 on EOF
109: */
110: public int read() {
111: try {
112: byte b = mappedByteBuffer.get();
113: int n = b & 0xff;
114:
115: return n;
116: } catch (BufferUnderflowException e) {
117: return -1; // EOF
118: }
119: }
120:
121: /**
122: * @see java.io.RandomAccessFile#read(byte[], int, int)
123: * @param bytes byte[]
124: * @param off int offset
125: * @param len int length
126: * @return int bytes read or -1 on EOF
127: */
128: public int read(byte bytes[], int off, int len) {
129: int pos = mappedByteBuffer.position();
130: int limit = mappedByteBuffer.limit();
131: if (pos == limit)
132: return -1; // EOF
133: int newlimit = pos + len - off;
134: if (newlimit > limit) {
135: len = limit - pos; // don't read beyond EOF
136: }
137: mappedByteBuffer.get(bytes, off, len);
138: return len;
139: }
140:
141: /**
142: * @see java.io.RandomAccessFile#getFilePointer()
143: * @return long
144: */
145: public long getFilePointer() {
146: return mappedByteBuffer.position();
147: }
148:
149: /**
150: * @see java.io.RandomAccessFile#seek(long)
151: * @param pos long position
152: */
153: public void seek(long pos) {
154: mappedByteBuffer.position((int) pos);
155: }
156:
157: /**
158: * @see java.io.RandomAccessFile#length()
159: * @return long length
160: */
161: public long length() {
162: return mappedByteBuffer.limit();
163: }
164:
165: /**
166: * @see java.io.RandomAccessFile#close()
167: * Cleans the mapped bytebuffer and closes the channel
168: */
169: public void close() throws IOException {
170: clean(mappedByteBuffer);
171: mappedByteBuffer = null;
172: if (channel != null)
173: channel.close();
174: channel = null;
175: }
176:
177: /**
178: * invokes the close method
179: * @see java.lang.Object#finalize()
180: */
181: protected void finalize() throws Throwable {
182: close();
183: super .finalize();
184: }
185:
186: /**
187: * invokes the clean method on the ByteBuffer's cleaner
188: * @param buffer ByteBuffer
189: * @return boolean true on success
190: */
191: public static boolean clean(final java.nio.ByteBuffer buffer) {
192: if (buffer == null || !buffer.isDirect())
193: return false;
194:
195: Boolean b = (Boolean) AccessController
196: .doPrivileged(new PrivilegedAction() {
197: public Object run() {
198: Boolean success = Boolean.FALSE;
199: try {
200: Method getCleanerMethod = buffer.getClass()
201: .getMethod("cleaner", null);
202: getCleanerMethod.setAccessible(true);
203: Object cleaner = getCleanerMethod.invoke(
204: buffer, null);
205: Method clean = cleaner.getClass()
206: .getMethod("clean", null);
207: clean.invoke(cleaner, null);
208: success = Boolean.TRUE;
209: } catch (Exception e) {
210: // This really is a show stopper on windows
211: //e.printStackTrace();
212: }
213: return success;
214: }
215: });
216:
217: return b.booleanValue();
218: }
219:
220: }
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