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1
49 package com.lowagie.text.pdf;
50
51 import java.io.FileInputStream  ;
52 import java.io.FileNotFoundException ;
53 import java.io.IOException ;
54 import java.lang.reflect.Method ;
55 import java.nio.BufferUnderflowException ;
56 import java.nio.MappedByteBuffer ;
57 import java.nio.channels.FileChannel ;
58 import java.security.AccessController ;
59 import java.security.PrivilegedAction ;
60
61
67 public class MappedRandomAccessFile {
68
69 private MappedByteBuffer mappedByteBuffer = null;
70 private FileChannel channel = null;
71
72
79 public MappedRandomAccessFile(String filename, String mode)
80 throws FileNotFoundException , IOException {
81
82 if (mode.equals("rw"))
83 init(
84 new java.io.RandomAccessFile (filename, mode).getChannel(),
85 FileChannel.MapMode.READ_WRITE);
86 else
87 init(
88 new FileInputStream (filename).getChannel(),
89 FileChannel.MapMode.READ_ONLY);
90
91 }
92
93
99 private void init(FileChannel channel, FileChannel.MapMode mapMode)
100 throws IOException {
101
102 this.channel = channel;
103 this.mappedByteBuffer = channel.map(mapMode, 0L, channel.size());
104 mappedByteBuffer.load();
105 }
106
107
111 public int read() {
112 try {
113 byte b = mappedByteBuffer.get();
114 int n = b & 0xff;
115
116 return n;
117 } catch (BufferUnderflowException e) {
118 return -1; }
120 }
121
122
129 public int read(byte bytes[], int off, int len) {
130 int pos = mappedByteBuffer.position();
131 int limit = mappedByteBuffer.limit();
132 if (pos == limit)
133 return -1; int newlimit = pos + len - off;
135 if (newlimit > limit) {
136 len = limit - pos; }
138 mappedByteBuffer.get(bytes, off, len);
139 return len;
140 }
141
142
146 public long getFilePointer() {
147 return mappedByteBuffer.position();
148 }
149
150
154 public void seek(long pos) {
155 mappedByteBuffer.position((int) pos);
156 }
157
158
162 public long length() {
163 return mappedByteBuffer.limit();
164 }
165
166
170 public void close() throws IOException {
171 clean(mappedByteBuffer);
172 mappedByteBuffer = null;
173 if (channel != null)
174 channel.close();
175 channel = null;
176 }
177
178
182 protected void finalize() throws Throwable {
183 close();
184 super.finalize();
185 }
186
187
192 public static boolean clean(final java.nio.ByteBuffer buffer) {
193 if (buffer == null || !buffer.isDirect())
194 return false;
195
196 Boolean b = (Boolean ) AccessController.doPrivileged(new PrivilegedAction () {
197 public Object run() {
198 Boolean success = Boolean.FALSE;
199 try {
200 Method getCleanerMethod = buffer.getClass().getMethod("cleaner", null);
201 getCleanerMethod.setAccessible(true);
202 Object cleaner = getCleanerMethod.invoke(buffer, null);
203 Method clean = cleaner.getClass().getMethod("clean", null);
204 clean.invoke(cleaner, null);
205 success = Boolean.TRUE;
206 } catch (Exception e) {
207 }
210 return success;
211 }
212 });
213
214 return b.booleanValue();
215 }
216
217 }
218 |
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