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最新评论
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Donald_Draper:
Donald_Draper 写道刘落落cici 写道能给我发一 ...
DatagramChannelImpl 解析三(多播) -
Donald_Draper:
刘落落cici 写道能给我发一份这个类的源码吗Datagram ...
DatagramChannelImpl 解析三(多播) -
lyfyouyun:
请问楼主,执行消息发送的时候,报错:Transport sch ...
ActiveMQ连接工厂、连接详解 -
ezlhq:
关于 PollArrayWrapper 状态含义猜测:参考 S ...
WindowsSelectorImpl解析一(FdMap,PollArrayWrapper) -
flyfeifei66:
打算使用xmemcache作为memcache的客户端,由于x ...
Memcached分布式客户端(Xmemcached)
ByteChannel,分散聚集通道接口的定义(SocketChannel):http://donald-draper.iteye.com/blog/2371065
package java.nio.channels; import java.nio.ByteBuffer; import java.io.IOException; /** * A byte channel that maintains a current <i>position</i> and allows the * position to be changed. *SeekableByteChannel维护是一个当前position,运行修改position。 * <p> A seekable byte channel is connected to an entity, typically a file, * that contains a variable-length sequence of bytes that can be read and * written. The current position can be {@link #position() <i>queried</i>} and * {@link #position(long) <i>modified</i>}. The channel also provides access to * the current <i>size</i> of the entity to which the channel is connected. The * size increases when bytes are written beyond its current size; the size * decreases when it is {@link #truncate <i>truncated</i>}. *SeekableByteChannel连接一个实体,典型为一个包含可变长度的字节序列文件,可以读取 和写。可通过#position方法获取当前位置,通过#position(long)修改当前position。通道 提供了访问通道连接实体的当前size。当字节序列被写到实体时,实体size增加;当压缩时, 实体size减少。 * <p> The {@link #position(long) position} and {@link #truncate truncate} methods * which do not otherwise have a value to return are specified to return the * channel upon which they are invoked. This allows method invocations to be * chained. Implementations of this interface should specialize the return type * so that method invocations on the implementation class can be chained. *#position(long)和#truncate方法,在调用时,返回的值是不确定。这些方法可以链式调用。 接口的实现,将该使这些方法返回一个精确的子,以便链式调用。 * @since 1.7 * @see java.nio.file.Files#newByteChannel */ public interface SeekableByteChannel extends ByteChannel { /** * Reads a sequence of bytes from this channel into the given buffer. *从通道读取字节序列,写到buffer中 * <p> Bytes are read starting at this channel's current position, and * then the position is updated with the number of bytes actually read. * Otherwise this method behaves exactly as specified in the {@link * ReadableByteChannel} interface. 从当前通道的postion位置开始读取字节,当实际字节被读取时,则更细positon。其他 的和ReadableByteChannel接口相同 */ @Override int read(ByteBuffer dst) throws IOException; /** * Writes a sequence of bytes to this channel from the given buffer. *从给定的buffer,读取字节序列写到通道中 * <p> Bytes are written starting at this channel's current position, unless * the channel is connected to an entity such as a file that is opened with * the {@link java.nio.file.StandardOpenOption#APPEND APPEND} option, in * which case the position is first advanced to the end. The entity to which * the channel is connected is grown, if necessary, to accommodate the * written bytes, and then the position is updated with the number of bytes * actually written. Otherwise this method behaves exactly as specified by * the {@link WritableByteChannel} interface. 从通道当前的位置写字节序列,除非通道连接一个实体,比如以StandardOpenOption#APPEND 配置选项打开的文件,在这种情况下,position首先定位到文件的尾部。通道连接的实际将会 增加,如果需要,计算写的字节数,更新position。其他方法与WritableByteChannel相同。 */ @Override int write(ByteBuffer src) throws IOException; /** * Returns this channel's position. *返回当前通道的位置 * @return This channel's position, * a non-negative integer counting the number of bytes * from the beginning of the entity to the current position * * @throws ClosedChannelException * If this channel is closed * @throws IOException * If some other I/O error occurs */ long position() throws IOException; /** * Sets this channel's position. *设置通道的位置 * <p> Setting the position to a value that is greater than the current size * is legal but does not change the size of the entity. A later attempt to * read bytes at such a position will immediately return an end-of-file * indication. A later attempt to write bytes at such a position will cause * the entity to grow to accommodate the new bytes; the values of any bytes * between the previous end-of-file and the newly-written bytes are * unspecified. *如果设置position大于当前实体size,是合法的,不会改变实体的size。尝试从设置后的 position位置读取字节,position将会立即定位到文件的末端。此时尝试写字节序列, 将会引起实体的增加。 * <p> Setting the channel's position is not recommended when connected to * an entity, typically a file, that is opened with the {@link * java.nio.file.StandardOpenOption#APPEND APPEND} option. When opened for * append, the position is first advanced to the end before writing. *当通道连接一个实体时,不建议设置通道的position,特别是一个以StandardOpenOption#APPEND 配置选项打开的文件,在这种情况下,在写之前,首先定位position的位置到文件的末尾。 * @param newPosition * The new position, a non-negative integer counting * the number of bytes from the beginning of the entity * * @return This channel * * @throws ClosedChannelException * If this channel is closed * @throws IllegalArgumentException * If the new position is negative * @throws IOException * If some other I/O error occurs */ SeekableByteChannel position(long newPosition) throws IOException; /** * Returns the current size of entity to which this channel is connected. *返回通道连接实体的size * @return The current size, measured in bytes * * @throws ClosedChannelException * If this channel is closed * @throws IOException * If some other I/O error occurs */ long size() throws IOException; /** * Truncates the entity, to which this channel is connected, to the given * size. *压缩通道连接的实体到指定的size * <p> If the given size is less than the current size then the entity is * truncated, discarding any bytes beyond the new end. If the given size is * greater than or equal to the current size then the entity is not modified. * In either case, if the current position is greater than the given size * then it is set to that size. *如果给定的size小于实体当前的size,将会压缩实体,丢弃超过新末端的字节。如果 给定的size大于或等于当前size,实际将不会修改。在其他一些情况下,如果当前的position 大于给定的size,那么将会设置position。 * <p> An implementation of this interface may prohibit truncation when * connected to an entity, typically a file, opened with the {@link * java.nio.file.StandardOpenOption#APPEND APPEND} option. *当连接一个实体时,具体接口的实现也许会禁止压缩实体,比如以StandardOpenOption#APPEND 配置选项打开的文件。 * @param size * The new size, a non-negative byte count * * @return This channel * * @throws NonWritableChannelException * If this channel was not opened for writing * @throws ClosedChannelException * If this channel is closed * @throws IllegalArgumentException * If the new size is negative * @throws IOException * If some other I/O error occurs */ SeekableByteChannel truncate(long size) throws IOException; }
发表评论
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文件通道解析二(文件锁,关闭通道)
2017-05-16 23:17 1064文件通道解析一(读写操作,通道数据传输等):http://do ... -
文件通道解析一(读写操作,通道数据传输等)
2017-05-16 10:04 1164Reference定义(PhantomRefere ... -
文件通道创建方式综述
2017-05-15 17:39 1065Reference定义(PhantomReference,Cl ... -
文件读写方式简单综述后续(文件,流构造)
2017-05-14 23:04 1480Java Socket通信实例:http://donald-d ... -
文件读写方式简单综述
2017-05-14 11:13 1135Java Socket通信实例:http://donald-d ... -
FileChanne定义
2017-05-12 23:28 936文件读写方式简单综述:http://donald-draper ... -
FileChannel示例
2017-05-11 08:37 992前面我们看过socket通道,datagram通道,以管道Pi ... -
PipeImpl解析
2017-05-11 08:41 932ServerSocketChannel定义:http://do ... -
Pipe定义
2017-05-10 09:07 903Channel接口定义:http://donald-drape ... -
NIO-Pipe示例
2017-05-10 08:47 905PipeImpl解析:http://donald-draper ... -
DatagramChannelImpl 解析四(地址绑定,关闭通道等)
2017-05-10 08:27 776DatagramChannelImpl 解析一(初始化):ht ... -
DatagramChannelImpl 解析三(多播)
2017-05-10 08:20 1893DatagramChannelImpl 解析一(初始化):ht ... -
NIO-UDP实例
2017-05-09 12:32 1584DatagramChannelImpl 解析一(初始化):ht ... -
DatagramChannelImpl 解析二(报文发送与接收)
2017-05-09 09:03 1405DatagramChannelImpl 解析一(初始化):ht ... -
DatagramChannelImpl 解析一(初始化)
2017-05-08 21:52 1406Channel接口定义:http://donald-drape ... -
MembershipKeyImpl 简介
2017-05-08 09:11 922MembershipKey定义:http://donald-d ... -
DatagramChannel定义
2017-05-07 23:13 1227Channel接口定义:http://donald-drape ... -
MulticastChanne接口定义
2017-05-07 13:45 1136NetworkChannel接口定义:ht ... -
MembershipKey定义
2017-05-06 16:20 915package java.nio.channels; i ... -
SocketChannelImpl 解析四(关闭通道等)
2017-05-05 08:38 2530SocketChannelImpl 解析一(通道连接,发送数据 ...
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