io.netty.handler.codec

类 LengthFieldPrepender

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelOutboundHandlerAdapter

io.netty.handler.codec.MessageToMessageEncoder<ByteBuf>

io.netty.handler.codec.LengthFieldPrepender

所有已实现的接口:

ChannelHandler, ChannelOutboundHandler

@ChannelHandler.Sharable
public class LengthFieldPrepender
extends MessageToMessageEncoder<ByteBuf>

An encoder that prepends the length of the message. The length value is prepended as a binary form.

For example, LengthFieldPrepender(2) will encode the following 12-bytes string:

 +----------------+
 | "HELLO, WORLD" |
 +----------------+
 

into the following:

 +--------+----------------+
 + 0x000C | "HELLO, WORLD" |
 +--------+----------------+
 

If you turned on the lengthIncludesLengthFieldLength flag in the constructor, the encoded data would look like the following (12 (original data) + 2 (prepended data) = 14 (0xE)):

 +--------+----------------+
 + 0x000E | "HELLO, WORLD" |
 +--------+----------------+
 

嵌套类概要

从接口继承的嵌套类/接口 io.netty.channel.ChannelHandler

ChannelHandler.Sharable

构造器概要

构造器

构造器和说明
LengthFieldPrepender(java.nio.ByteOrder byteOrder, int lengthFieldLength, int lengthAdjustment, boolean lengthIncludesLengthFieldLength) Creates a new instance.
LengthFieldPrepender(int lengthFieldLength) Creates a new instance.
LengthFieldPrepender(int lengthFieldLength, boolean lengthIncludesLengthFieldLength) Creates a new instance.
LengthFieldPrepender(int lengthFieldLength, int lengthAdjustment) Creates a new instance.
LengthFieldPrepender(int lengthFieldLength, int lengthAdjustment, boolean lengthIncludesLengthFieldLength) Creates a new instance.

方法概要

限定符和类型	方法和说明
protected void	encode(ChannelHandlerContext ctx, ByteBuf msg, java.util.List<java.lang.Object> out) Encode from one message to an other.

从类继承的方法 io.netty.handler.codec.MessageToMessageEncoder

acceptOutboundMessage, write

从类继承的方法 io.netty.channel.ChannelOutboundHandlerAdapter

bind, close, connect, deregister, disconnect, flush, read

从类继承的方法 io.netty.channel.ChannelHandlerAdapter

ensureNotSharable, exceptionCaught, handlerAdded, handlerRemoved, isSharable

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 io.netty.channel.ChannelHandler

exceptionCaught, handlerAdded, handlerRemoved

构造器详细资料

LengthFieldPrepender

public LengthFieldPrepender(int lengthFieldLength)

Creates a new instance.

参数:

lengthFieldLength - the length of the prepended length field. Only 1, 2, 3, 4, and 8 are allowed.

抛出:

java.lang.IllegalArgumentException - if lengthFieldLength is not 1, 2, 3, 4, or 8

LengthFieldPrepender

public LengthFieldPrepender(int lengthFieldLength,
                            boolean lengthIncludesLengthFieldLength)

Creates a new instance.

参数:

lengthFieldLength - the length of the prepended length field. Only 1, 2, 3, 4, and 8 are allowed.

lengthIncludesLengthFieldLength - if true, the length of the prepended length field is added to the value of the prepended length field.

抛出:

java.lang.IllegalArgumentException - if lengthFieldLength is not 1, 2, 3, 4, or 8

LengthFieldPrepender

public LengthFieldPrepender(int lengthFieldLength,
                            int lengthAdjustment)

Creates a new instance.

参数:

lengthFieldLength - the length of the prepended length field. Only 1, 2, 3, 4, and 8 are allowed.

lengthAdjustment - the compensation value to add to the value of the length field

抛出:

java.lang.IllegalArgumentException - if lengthFieldLength is not 1, 2, 3, 4, or 8

LengthFieldPrepender

public LengthFieldPrepender(int lengthFieldLength,
                            int lengthAdjustment,
                            boolean lengthIncludesLengthFieldLength)

Creates a new instance.

参数:

lengthFieldLength - the length of the prepended length field. Only 1, 2, 3, 4, and 8 are allowed.

lengthAdjustment - the compensation value to add to the value of the length field

lengthIncludesLengthFieldLength - if true, the length of the prepended length field is added to the value of the prepended length field.

抛出:

java.lang.IllegalArgumentException - if lengthFieldLength is not 1, 2, 3, 4, or 8

LengthFieldPrepender

public LengthFieldPrepender(java.nio.ByteOrder byteOrder,
                            int lengthFieldLength,
                            int lengthAdjustment,
                            boolean lengthIncludesLengthFieldLength)

Creates a new instance.

参数:

byteOrder - the ByteOrder of the length field

lengthFieldLength - the length of the prepended length field. Only 1, 2, 3, 4, and 8 are allowed.

lengthAdjustment - the compensation value to add to the value of the length field

lengthIncludesLengthFieldLength - if true, the length of the prepended length field is added to the value of the prepended length field.

抛出:

java.lang.IllegalArgumentException - if lengthFieldLength is not 1, 2, 3, 4, or 8

方法详细资料

encode

protected void encode(ChannelHandlerContext ctx,
                      ByteBuf msg,
                      java.util.List<java.lang.Object> out)
               throws java.lang.Exception

从类复制的说明: MessageToMessageEncoder

Encode from one message to an other. This method will be called for each written message that can be handled by this encoder.

指定者:

encode 在类中 MessageToMessageEncoder<ByteBuf>

参数:

ctx - the ChannelHandlerContext which this MessageToMessageEncoder belongs to

msg - the message to encode to an other one

out - the List into which the encoded msg should be added needs to do some kind of aggregation

抛出:

java.lang.Exception - is thrown if an error occurs