org.apache.hadoop.io

类 DataOutputBuffer

java.lang.Object

java.io.OutputStream

java.io.FilterOutputStream

java.io.DataOutputStream

org.apache.hadoop.io.DataOutputBuffer

所有已实现的接口:

Closeable, DataOutput, Flushable, AutoCloseable

public class DataOutputBuffer
extends DataOutputStream

A reusable DataOutput implementation that writes to an in-memory buffer.

This saves memory over creating a new DataOutputStream and ByteArrayOutputStream each time data is written.

Typical usage is something like the following:

 DataOutputBuffer buffer = new DataOutputBuffer();
 while (... loop condition ...) {
   buffer.reset();
   ... write buffer using DataOutput methods ...
   byte[] data = buffer.getData();
   int dataLength = buffer.getLength();
   ... write data to its ultimate destination ...
 }
 

字段概要

从类继承的字段 java.io.DataOutputStream

written

从类继承的字段 java.io.FilterOutputStream

out

构造器概要

构造器

构造器和说明
DataOutputBuffer() Constructs a new empty buffer.
DataOutputBuffer(int size)

方法概要

方法

限定符和类型	方法和说明
byte[]	getData() Returns the current contents of the buffer.
int	getLength() Returns the length of the valid data currently in the buffer.
DataOutputBuffer	reset() Resets the buffer to empty.
void	write(DataInput in, int length) Writes bytes from a DataInput directly into the buffer.
void	writeTo(OutputStream out) Write to a file stream

从类继承的方法 java.io.DataOutputStream

flush, size, write, write, writeBoolean, writeByte, writeBytes, writeChar, writeChars, writeDouble, writeFloat, writeInt, writeLong, writeShort, writeUTF

从类继承的方法 java.io.FilterOutputStream

close, write

从类继承的方法 java.lang.Object

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

从接口继承的方法 java.io.DataOutput

write

构造器详细资料

DataOutputBuffer

public DataOutputBuffer()

Constructs a new empty buffer.

DataOutputBuffer

public DataOutputBuffer(int size)

方法详细资料

getData

public byte[] getData()

Returns the current contents of the buffer. Data is only valid to getLength().

getLength

public int getLength()

Returns the length of the valid data currently in the buffer.

reset

public DataOutputBuffer reset()

Resets the buffer to empty.

write

public void write(DataInput in,
         int length)
           throws IOException

Writes bytes from a DataInput directly into the buffer.

抛出:

IOException

writeTo

public void writeTo(OutputStream out)
             throws IOException

Write to a file stream

抛出:

IOException