本文整理汇总了Java中java.nio.channels.FileChannel.MapMode.READ_ONLY属性的典型用法代码示例。如果您正苦于以下问题：Java MapMode.READ_ONLY属性的具体用法？Java MapMode.READ_ONLY怎么用？Java MapMode.READ_ONLY使用的例子？那么恭喜您, 这里精选的属性代码示例或许可以为您提供帮助。您也可以进一步了解该属性所在类java.nio.channels.FileChannel.MapMode的用法示例。
在下文中一共展示了MapMode.READ_ONLY属性的2个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的Java代码示例。
示例1: MemoryMappedFile
public MemoryMappedFile(File file, String mode, long offset, long size) throws IOException {
if (size >= Integer.MAX_VALUE) {
throw new IllegalArgumentException("jvm doesn't support mapped file more than 2g");
}
MapMode mapmode = null;
if (mode.equals("r")) {
mapmode = MapMode.READ_ONLY;
}
else if (mode.equals("rw")) {
mapmode = MapMode.READ_WRITE;
}
else {
throw new IllegalArgumentException();
}
if ((mapmode == MapMode.READ_WRITE) && !file.exists()) {
File parent = file.getAbsoluteFile().getParentFile();
long free = parent.getUsableSpace();
if ((size * 4) > free) {
throw new HumpbackException("out of storage space: " + file.toString() + ' ' + free);
}
}
this.file = file;
boolean exist = this.file.exists();
this.raf = new RandomAccessFile(file, mode);
this.channel = raf.getChannel();
this.buf = channel.map(mapmode, offset, size);
this.buf.order(ByteOrder.nativeOrder());
this.addr = UberUtil.getAddress(buf);
_log.debug(String.format("mounted %s %s %s at 0x%016x with length 0x%08x",
exist ? "exist" : "new",
file.toString(),
mode,
addr,
size));
}
示例2: map
/**
* Note: copied from Google Guava under Apache License v2.
*
* Maps a file in to memory as per
* {@link FileChannel#map(java.nio.channels.FileChannel.MapMode, long, long)}
* using the requested {@link MapMode}.
*
* <p>Files are mapped from offset 0 to {@code size}.
*
* <p>If the mode is {@link MapMode#READ_WRITE} and the file does not exist,
* it will be created with the requested {@code size}. Thus this method is
* useful for creating memory mapped files which do not yet exist.
*
* <p>This only works for files <= {@link Integer#MAX_VALUE} bytes.
*
* @param file the file to map
* @param mode the mode to use when mapping {@code file}
* @param offset
* @param len
* @return a buffer reflecting {@code file}
*
* @see FileChannel#map(MapMode, long, long)
* @since 2.0
*/
public static MappedByteBuffer map(File file, MapMode mode, long offset, long len) {
N.requireNonNull(file);
N.requireNonNull(mode);
RandomAccessFile raf = null;
try {
raf = new RandomAccessFile(file, mode == MapMode.READ_ONLY ? "r" : "rw");
return raf.getChannel().map(mode, offset, len);
} catch (IOException e) {
throw new UncheckedIOException(e);
} finally {
IOUtil.closeQuietly(raf);
}
}