java.io
Class OutputStream

java.lang.Object
  java.io.OutputStream

Direct Known Subclasses:

ByteArrayOutputStream, FileOutputStream, FilterOutputStream, ObjectOutputStream, OutputStream, PipedOutputStream

public abstract class OutputStream

extends Object

This abstract class is the superclass of all classes representing an output stream of bytes. An output stream accepts output bytes and sends them to some sink. 该抽象类是所有表示字节输出流的类的父类。OutputStream接收输入的字节，并将其输出到指定的接收器中。

Applications that need to define a subclass of OutputStream must always provide at least a method that writes one byte of output. 应用程序需要定义OutputStream的子类，该子类至少应定义一个方法，用来输出一个字节。

Since:

JDK1.0

See Also:

BufferedOutputStream, ByteArrayOutputStream, DataOutputStream, FilterOutputStream, InputStream, write(int)

Constructor Summary

OutputStream()

 

Method Summary
void	close()           Closes this output stream and releases any system resources associated with this stream.关闭输出流，释放所有相关的系统资源。
void	flush()           Flushes this output stream and forces any buffered output bytes to be written out.刷新输出流，使缓存数据被写出。
void	write(byte[] b)           Writes b.length bytes from the specified byte array to this output stream.将指定b.length长度的字节数组写入输出流。
void	write(byte[] b, int off, int len)           Writes len bytes from the specified byte array starting at offset off to this output stream.将指定字节数组off起始位置，len长度的字节写入输出流。
abstract  void	write(int b)           Writes the specified byte to this output stream.将指定的字节写入输出流。

 

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

 

Constructor Detail

OutputStream

public OutputStream()

write

public abstract void write(int b)
                    throws IOException

Writes the specified byte to this output stream. The general contract for write is that one byte is written to the output stream. The byte to be written is the eight low-order bits of the argument b. The 24 high-order bits of b are ignored. 将指定字节数组写入输出流。write通常约定为向输出流写入一个字节，被写入的字节是参数b的低8位，其余24位忽略。

Subclasses of OutputStream must provide an implementation for this method. OutputStream的子类必须实现该方法。

Parameters:

b - the byte. 该字节。

Throws:

IOException - if an I/O error occurs. In particular, an IOException may be thrown if the output stream has been closed. 发生I/O错误时抛出，特别注意输出流已被关闭时也可能抛出IOException。

write

public void write(byte[] b)
           throws IOException

Writes b.length bytes from the specified byte array to this output stream. The general contract for write(b) is that it should have exactly the same effect as the call write(b, 0, b.length). 将指定b.length长度的字节数组写入输出流。write(b)通常约定为和write(b, 0, b.length)等效。

Parameters:

b - the data. 数据。

Throws:

IOException - if an I/O error occurs. 发生I/O错误时抛出。

See Also:

write(byte[], int, int)

write

public void write(byte[] b,
                  int off,
                  int len)
           throws IOException

Writes len bytes from the specified byte array starting at offset off to this output stream. The general contract for write(b, off, len) is that some of the bytes in the array b are written to the output stream in order; element b[off] is the first byte written and b[off+len-1] is the last byte written by this operation. 将指定字节数组off起始位置，len长度的字节写入输出流。write(b, off, len)通常约定为数组b中的字节应该按顺序写入，元素 b[off]是第一个被写入的字节，b[off+len-1]是操作中写入的最后一个字节。

The write method of OutputStream calls the write method of one argument on each of the bytes to be written out. Subclasses are encouraged to override this method and provide a more efficient implementation. OutputStream的write方法调用以每个字节为参数的write方法进行输出。建议子类应该重载该方法，以提供更有效的实现。

If b is null, a NullPointerException is thrown. 如果b为null，抛出NullPointerException。

If off is negative, or len is negative, or off+len is greater than the length of the array b, then an IndexOutOfBoundsException is thrown. 如果off是负数，len是负数，或者off+len大于数组b的长度，那么抛出IndexOutOfBoundsException。

Parameters:

b - the data. 数据。

off - the start offset in the data. 数据的起始偏移。

len - the number of bytes to write. 写入的字节数。

Throws:

IOException - if an I/O error occurs. In particular, an IOException is thrown if the output stream is closed. 发生I/O错误时抛出，特别注意输出流已被关闭时也可能抛出IOException。

flush

public void flush()
           throws IOException

Flushes this output stream and forces any buffered output bytes to be written out. The general contract of flush is that calling it is an indication that, if any bytes previously written have been buffered by the implementation of the output stream, such bytes should immediately be written to their intended destination. 刷新输出流，使缓存数据被写出。flush通常约定为调用该指令时，任何实现OutputStream的类应当将先前被缓存的字节立即写入目的地。

The flush method of OutputStream does nothing. OutputStream的flush方法不做任何事。

Throws:

IOException - if an I/O error occurs. 发生I/O错误时抛出。

close

public void close()
           throws IOException

Closes this output stream and releases any system resources associated with this stream. The general contract of close is that it closes the output stream. A closed stream cannot perform output operations and cannot be reopened. 关闭输出流，释放所有相关的系统资源。close通常约定为关闭输出流，关闭的输出流不能执行输出操作，也不能重新被打开。

The close method of OutputStream does nothing. OutputStream的close方法不做任何事。

Throws:

IOException - if an I/O error occurs. 发生I/O错误时抛出。

Copyright 2003 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.