1 |
14 |
jlechner |
/* FileChannel.java --
|
2 |
|
|
Copyright (C) 2002 Free Software Foundation, Inc.
|
3 |
|
|
|
4 |
|
|
This file is part of GNU Classpath.
|
5 |
|
|
|
6 |
|
|
GNU Classpath is free software; you can redistribute it and/or modify
|
7 |
|
|
it under the terms of the GNU General Public License as published by
|
8 |
|
|
the Free Software Foundation; either version 2, or (at your option)
|
9 |
|
|
any later version.
|
10 |
|
|
|
11 |
|
|
GNU Classpath is distributed in the hope that it will be useful, but
|
12 |
|
|
WITHOUT ANY WARRANTY; without even the implied warranty of
|
13 |
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
14 |
|
|
General Public License for more details.
|
15 |
|
|
|
16 |
|
|
You should have received a copy of the GNU General Public License
|
17 |
|
|
along with GNU Classpath; see the file COPYING. If not, write to the
|
18 |
|
|
Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
|
19 |
|
|
02110-1301 USA.
|
20 |
|
|
|
21 |
|
|
Linking this library statically or dynamically with other modules is
|
22 |
|
|
making a combined work based on this library. Thus, the terms and
|
23 |
|
|
conditions of the GNU General Public License cover the whole
|
24 |
|
|
combination.
|
25 |
|
|
|
26 |
|
|
As a special exception, the copyright holders of this library give you
|
27 |
|
|
permission to link this library with independent modules to produce an
|
28 |
|
|
executable, regardless of the license terms of these independent
|
29 |
|
|
modules, and to copy and distribute the resulting executable under
|
30 |
|
|
terms of your choice, provided that you also meet, for each linked
|
31 |
|
|
independent module, the terms and conditions of the license of that
|
32 |
|
|
module. An independent module is a module which is not derived from
|
33 |
|
|
or based on this library. If you modify this library, you may extend
|
34 |
|
|
this exception to your version of the library, but you are not
|
35 |
|
|
obligated to do so. If you do not wish to do so, delete this
|
36 |
|
|
exception statement from your version. */
|
37 |
|
|
|
38 |
|
|
package java.nio.channels;
|
39 |
|
|
|
40 |
|
|
import java.io.IOException;
|
41 |
|
|
import java.nio.ByteBuffer;
|
42 |
|
|
import java.nio.MappedByteBuffer;
|
43 |
|
|
import java.nio.channels.spi.AbstractInterruptibleChannel;
|
44 |
|
|
|
45 |
|
|
|
46 |
|
|
/**
|
47 |
|
|
* @author Michael Koch
|
48 |
|
|
* @since 1.4
|
49 |
|
|
*/
|
50 |
|
|
public abstract class FileChannel extends AbstractInterruptibleChannel
|
51 |
|
|
implements ByteChannel, GatheringByteChannel, ScatteringByteChannel
|
52 |
|
|
{
|
53 |
|
|
public static class MapMode
|
54 |
|
|
{
|
55 |
|
|
int m;
|
56 |
|
|
public static final MapMode READ_ONLY = new MapMode(0);
|
57 |
|
|
public static final MapMode READ_WRITE = new MapMode(1);
|
58 |
|
|
public static final MapMode PRIVATE = new MapMode(2);
|
59 |
|
|
|
60 |
|
|
/**
|
61 |
|
|
* Initializes the MapMode.
|
62 |
|
|
*/
|
63 |
|
|
MapMode(int a)
|
64 |
|
|
{
|
65 |
|
|
m = a;
|
66 |
|
|
}
|
67 |
|
|
|
68 |
|
|
/**
|
69 |
|
|
* Returns a string representation of the <code>MapMode</code> object.
|
70 |
|
|
*/
|
71 |
|
|
public String toString()
|
72 |
|
|
{
|
73 |
|
|
if (this == READ_ONLY)
|
74 |
|
|
return "READ_ONLY";
|
75 |
|
|
else if (this == READ_WRITE)
|
76 |
|
|
return "READ_WRITE";
|
77 |
|
|
|
78 |
|
|
return "PRIVATE";
|
79 |
|
|
}
|
80 |
|
|
}
|
81 |
|
|
|
82 |
|
|
/**
|
83 |
|
|
* Initializes the channel.
|
84 |
|
|
*/
|
85 |
|
|
protected FileChannel()
|
86 |
|
|
{
|
87 |
|
|
}
|
88 |
|
|
|
89 |
|
|
/**
|
90 |
|
|
* Maps the file into the memory.
|
91 |
|
|
*
|
92 |
|
|
* @exception IllegalArgumentException If the preconditions on the parameters
|
93 |
|
|
* do not hold.
|
94 |
|
|
* @exception IOException If an I/O error occurs.
|
95 |
|
|
* @exception NonReadableChannelException If mode is READ_ONLY but this channel was
|
96 |
|
|
* not opened for reading.
|
97 |
|
|
* @exception NonWritableChannelException If mode is READ_WRITE or PRIVATE but this
|
98 |
|
|
* channel was not opened for writing.
|
99 |
|
|
*/
|
100 |
|
|
public abstract MappedByteBuffer map(MapMode mode, long position, long size)
|
101 |
|
|
throws IOException;
|
102 |
|
|
|
103 |
|
|
/**
|
104 |
|
|
* Return the size of the file thus far
|
105 |
|
|
*
|
106 |
|
|
* @exception ClosedChannelException If this channel is closed.
|
107 |
|
|
*/
|
108 |
|
|
public abstract long size() throws IOException;
|
109 |
|
|
|
110 |
|
|
/**
|
111 |
|
|
* Writes data to the channel.
|
112 |
|
|
*
|
113 |
|
|
* @exception IOException If an I/O error occurs.
|
114 |
|
|
*/
|
115 |
|
|
public final long write(ByteBuffer[] srcs) throws IOException
|
116 |
|
|
{
|
117 |
|
|
long result = 0;
|
118 |
|
|
|
119 |
|
|
for (int i = 0; i < srcs.length; i++)
|
120 |
|
|
result += write(srcs[i]);
|
121 |
|
|
|
122 |
|
|
return result;
|
123 |
|
|
}
|
124 |
|
|
|
125 |
|
|
/**
|
126 |
|
|
* Writes data to the channel.
|
127 |
|
|
*
|
128 |
|
|
* @exception IOException If an I/O error occurs.
|
129 |
|
|
*/
|
130 |
|
|
public abstract int write(ByteBuffer src) throws IOException;
|
131 |
|
|
|
132 |
|
|
/**
|
133 |
|
|
* Writes data to the channel.
|
134 |
|
|
*
|
135 |
|
|
* @exception AsynchronousCloseException If another thread closes this channel
|
136 |
|
|
* while the transfer is in progress.
|
137 |
|
|
* @exception ClosedByInterruptException If another thread interrupts the
|
138 |
|
|
* current thread while the transfer is in progress, thereby closing both
|
139 |
|
|
* channels and setting the current thread's interrupt status.
|
140 |
|
|
* @exception ClosedChannelException If this channel is closed.
|
141 |
|
|
* @exception IllegalArgumentException If position is negative.
|
142 |
|
|
* @exception IOException If an I/O error occurs.
|
143 |
|
|
* @exception NonWritableChannelException If this channel was not opened for
|
144 |
|
|
* writing.
|
145 |
|
|
*/
|
146 |
|
|
public abstract int write(ByteBuffer srcs, long position)
|
147 |
|
|
throws IOException;
|
148 |
|
|
|
149 |
|
|
/**
|
150 |
|
|
* Writes data to the channel.
|
151 |
|
|
*
|
152 |
|
|
* @exception IOException If an I/O error occurs.
|
153 |
|
|
*/
|
154 |
|
|
public abstract long write(ByteBuffer[] srcs, int offset, int length)
|
155 |
|
|
throws IOException;
|
156 |
|
|
|
157 |
|
|
/**
|
158 |
|
|
* Reads data from the channel.
|
159 |
|
|
*
|
160 |
|
|
* @exception IOException If an I/O error occurs.
|
161 |
|
|
*/
|
162 |
|
|
public abstract long read(ByteBuffer[] dsts, int offset, int length)
|
163 |
|
|
throws IOException;
|
164 |
|
|
|
165 |
|
|
/**
|
166 |
|
|
* Reads data from the channel.
|
167 |
|
|
*
|
168 |
|
|
* @exception IOException If an I/O error occurs.
|
169 |
|
|
*/
|
170 |
|
|
public final long read(ByteBuffer[] dsts) throws IOException
|
171 |
|
|
{
|
172 |
|
|
long result = 0;
|
173 |
|
|
|
174 |
|
|
for (int i = 0; i < dsts.length; i++)
|
175 |
|
|
read(dsts[i]);
|
176 |
|
|
|
177 |
|
|
return result;
|
178 |
|
|
}
|
179 |
|
|
|
180 |
|
|
/**
|
181 |
|
|
* Reads data from the channel.
|
182 |
|
|
*
|
183 |
|
|
* @exception IOException If an I/O error occurs.
|
184 |
|
|
*/
|
185 |
|
|
public abstract int read(ByteBuffer dst) throws IOException;
|
186 |
|
|
|
187 |
|
|
/**
|
188 |
|
|
* Reads data from the channel.
|
189 |
|
|
*
|
190 |
|
|
* @exception AsynchronousCloseException If another thread closes this channel
|
191 |
|
|
* while the transfer is in progress.
|
192 |
|
|
* @exception ClosedByInterruptException If another thread interrupts the
|
193 |
|
|
* current thread while the transfer is in progress, thereby closing both
|
194 |
|
|
* channels and setting the current thread's interrupt status.
|
195 |
|
|
* @exception ClosedChannelException If this channel is closed.
|
196 |
|
|
* @exception IllegalArgumentException If position is negative.
|
197 |
|
|
* @exception IOException If an I/O error occurs.
|
198 |
|
|
* @exception NonReadableChannelException If this channel was not opened for
|
199 |
|
|
* reading.
|
200 |
|
|
*/
|
201 |
|
|
public abstract int read(ByteBuffer dst, long position)
|
202 |
|
|
throws IOException;
|
203 |
|
|
|
204 |
|
|
/**
|
205 |
|
|
* Closes the channel.
|
206 |
|
|
*
|
207 |
|
|
* This is called from @see close.
|
208 |
|
|
*
|
209 |
|
|
* @exception IOException If an I/O error occurs.
|
210 |
|
|
*/
|
211 |
|
|
protected abstract void implCloseChannel() throws IOException;
|
212 |
|
|
|
213 |
|
|
/**
|
214 |
|
|
* msync with the disk
|
215 |
|
|
*
|
216 |
|
|
* @exception ClosedChannelException If this channel is closed.
|
217 |
|
|
* @exception IOException If an I/O error occurs.
|
218 |
|
|
*/
|
219 |
|
|
public abstract void force(boolean metaData) throws IOException;
|
220 |
|
|
|
221 |
|
|
/**
|
222 |
|
|
* Creates a file lock for the whole assoziated file.
|
223 |
|
|
*
|
224 |
|
|
* @exception AsynchronousCloseException If another thread closes this channel
|
225 |
|
|
* while the transfer is in progress.
|
226 |
|
|
* @exception ClosedChannelException If this channel is closed.
|
227 |
|
|
* @exception FileLockInterruptionException If the invoking thread is
|
228 |
|
|
* interrupted while blocked in this method.
|
229 |
|
|
* @exception IOException If an I/O error occurs.
|
230 |
|
|
* @exception NonReadableChannelException If shared is true and this channel
|
231 |
|
|
* was not opened for reading.
|
232 |
|
|
* @exception NonWritableChannelException If shared is false and this channel
|
233 |
|
|
* was not opened for writing.
|
234 |
|
|
* @exception OverlappingFileLockException If a lock that overlaps the
|
235 |
|
|
* requested region is already held by this Java virtual machine, or if
|
236 |
|
|
* another thread is already blocked in this method and is attempting to lock
|
237 |
|
|
* an overlapping region.
|
238 |
|
|
*/
|
239 |
|
|
public final FileLock lock() throws IOException
|
240 |
|
|
{
|
241 |
|
|
return lock(0, Long.MAX_VALUE, false);
|
242 |
|
|
}
|
243 |
|
|
|
244 |
|
|
/**
|
245 |
|
|
* Creates a file lock for a region of the assoziated file.
|
246 |
|
|
*
|
247 |
|
|
* @exception AsynchronousCloseException If another thread closes this channel
|
248 |
|
|
* while the transfer is in progress.
|
249 |
|
|
* @exception ClosedChannelException If this channel is closed.
|
250 |
|
|
* @exception FileLockInterruptionException If the invoking thread is
|
251 |
|
|
* interrupted while blocked in this method.
|
252 |
|
|
* @exception IllegalArgumentException If the preconditions on the parameters
|
253 |
|
|
* do not hold.
|
254 |
|
|
* @exception IOException If an I/O error occurs.
|
255 |
|
|
* @exception OverlappingFileLockException If a lock that overlaps the
|
256 |
|
|
* requested region is already held by this Java virtual machine, or if
|
257 |
|
|
* another thread is already blocked in this method and is attempting to lock
|
258 |
|
|
* an overlapping region.
|
259 |
|
|
* @exception NonReadableChannelException If shared is true and this channel
|
260 |
|
|
* was not opened for reading.
|
261 |
|
|
* @exception NonWritableChannelException If shared is false and this channel
|
262 |
|
|
* was not opened for writing.
|
263 |
|
|
*/
|
264 |
|
|
public abstract FileLock lock(long position, long size, boolean shared)
|
265 |
|
|
throws IOException;
|
266 |
|
|
|
267 |
|
|
/**
|
268 |
|
|
* Tries to aqquire alock on the whole assoziated file.
|
269 |
|
|
*
|
270 |
|
|
* @exception ClosedChannelException If this channel is closed.
|
271 |
|
|
* @exception IOException If an I/O error occurs.
|
272 |
|
|
* @exception OverlappingFileLockException If a lock that overlaps the
|
273 |
|
|
* requested region is already held by this Java virtual machine, or if
|
274 |
|
|
* another thread is already blocked in this method and is attempting to lock
|
275 |
|
|
* an overlapping region.
|
276 |
|
|
*/
|
277 |
|
|
public final FileLock tryLock() throws IOException
|
278 |
|
|
{
|
279 |
|
|
return tryLock(0, Long.MAX_VALUE, false);
|
280 |
|
|
}
|
281 |
|
|
|
282 |
|
|
/**
|
283 |
|
|
* Tries to aqquire a lock on a region of the assoziated file.
|
284 |
|
|
*
|
285 |
|
|
* @exception ClosedChannelException If this channel is closed.
|
286 |
|
|
* @exception IllegalArgumentException If the preconditions on the parameters
|
287 |
|
|
* do not hold.
|
288 |
|
|
* @exception IOException If an I/O error occurs.
|
289 |
|
|
* @exception OverlappingFileLockException If a lock that overlaps the
|
290 |
|
|
* requested region is already held by this Java virtual machine, or if
|
291 |
|
|
* another thread is already blocked in this method and is attempting to lock
|
292 |
|
|
* an overlapping region.
|
293 |
|
|
*/
|
294 |
|
|
public abstract FileLock tryLock(long position, long size, boolean shared)
|
295 |
|
|
throws IOException;
|
296 |
|
|
|
297 |
|
|
/**
|
298 |
|
|
* Returns the current position on the file.
|
299 |
|
|
*
|
300 |
|
|
* @exception ClosedChannelException If this channel is closed.
|
301 |
|
|
* @exception IOException If an I/O error occurs.
|
302 |
|
|
*/
|
303 |
|
|
public abstract long position() throws IOException;
|
304 |
|
|
|
305 |
|
|
/**
|
306 |
|
|
* Sets the position of the channel on the assoziated file.
|
307 |
|
|
*
|
308 |
|
|
* @exception ClosedChannelException If this channel is closed.
|
309 |
|
|
* @exception IllegalArgumentException If newPosition is negative.
|
310 |
|
|
* @exception IOException If an I/O error occurs.
|
311 |
|
|
*/
|
312 |
|
|
public abstract FileChannel position(long newPosition)
|
313 |
|
|
throws IOException;
|
314 |
|
|
|
315 |
|
|
/**
|
316 |
|
|
* Transfers bytes from this channel's file to the given writable byte
|
317 |
|
|
* channel.
|
318 |
|
|
*
|
319 |
|
|
* @exception AsynchronousCloseException If another thread closes this channel
|
320 |
|
|
* while the transfer is in progress.
|
321 |
|
|
* @exception ClosedByInterruptException If another thread interrupts the
|
322 |
|
|
* current thread while the transfer is in progress, thereby closing both
|
323 |
|
|
* channels and setting the current thread's interrupt status.
|
324 |
|
|
* @exception ClosedChannelException If this channel is closed.
|
325 |
|
|
* @exception IllegalArgumentException If the preconditions on the parameters
|
326 |
|
|
* do not hold.
|
327 |
|
|
* @exception IOException If an I/O error occurs.
|
328 |
|
|
* @exception NonReadableChannelException If this channel was not opened for
|
329 |
|
|
* reading.
|
330 |
|
|
* @exception NonWritableChannelException If the target channel was not
|
331 |
|
|
* opened for writing.
|
332 |
|
|
*/
|
333 |
|
|
public abstract long transferTo(long position, long count,
|
334 |
|
|
WritableByteChannel target)
|
335 |
|
|
throws IOException;
|
336 |
|
|
|
337 |
|
|
/**
|
338 |
|
|
* Transfers bytes from the given readable channel into this channel.
|
339 |
|
|
*
|
340 |
|
|
* @exception AsynchronousCloseException If another thread closes this channel
|
341 |
|
|
* while the transfer is in progress.
|
342 |
|
|
* @exception ClosedByInterruptException If another thread interrupts the
|
343 |
|
|
* current thread while the transfer is in progress, thereby closing both
|
344 |
|
|
* channels and setting the current thread's interrupt status.
|
345 |
|
|
* @exception ClosedChannelException If this channel is closed.
|
346 |
|
|
* @exception IllegalArgumentException If the preconditions on the parameters
|
347 |
|
|
* do not hold.
|
348 |
|
|
* @exception IOException If an I/O error occurs.
|
349 |
|
|
* @exception NonReadableChannelException If the source channel was not
|
350 |
|
|
* opened for reading.
|
351 |
|
|
* @exception NonWritableChannelException If this channel was not opened for
|
352 |
|
|
* writing.
|
353 |
|
|
*/
|
354 |
|
|
public abstract long transferFrom(ReadableByteChannel src, long position,
|
355 |
|
|
long count) throws IOException;
|
356 |
|
|
|
357 |
|
|
/**
|
358 |
|
|
* Truncates the channel's file at <code>size</code>.
|
359 |
|
|
*
|
360 |
|
|
* @exception ClosedChannelException If this channel is closed.
|
361 |
|
|
* @exception IllegalArgumentException If size is negative.
|
362 |
|
|
* @exception IOException If an I/O error occurs.
|
363 |
|
|
* @exception NonWritableChannelException If this channel was not opened for
|
364 |
|
|
* writing.
|
365 |
|
|
*/
|
366 |
|
|
public abstract FileChannel truncate(long size) throws IOException;
|
367 |
|
|
}
|