Class MessageToByteEncoder<I>

io.netty.handler.codec.MessageToByteEncoder<I>

All Implemented Interfaces:: ChannelHandler, ChannelOutboundHandler

Direct Known Subclasses:: BrotliEncoder, Bzip2Encoder, CompatibleMarshallingEncoder, CompatibleObjectEncoder, FastLzFrameEncoder, HAProxyMessageEncoder, Lz4FrameEncoder, LzfEncoder, LzmaFrameEncoder, MarshallingEncoder, ObjectEncoder, ProtobufVarint32LengthFieldPrepender, SnappyFrameEncoder, Socks4ClientEncoder, Socks4ServerEncoder, Socks5ClientEncoder, Socks5ServerEncoder, SocksMessageEncoder, TcpDnsQueryEncoder, ZlibEncoder, ZstdEncoder

public abstract class MessageToByteEncoder<I> extends ChannelOutboundHandlerAdapter

ChannelOutboundHandlerAdapter which encodes message in a stream-like fashion from one message to an ByteBuf. Example implementation which encodes Integers to a ByteBuf.

 public class IntegerEncoder extends MessageToByteEncoder<Integer> {
 @Override
 public void encode(ChannelHandlerContext ctx, Integer msg, ByteBuf out)
 throws Exception {
 out.writeInt(msg);
 }
 }

Nested Class Summary

Nested classes/interfaces inherited from interface ChannelHandler
ChannelHandler.Sharable
Constructor Summary

Constructors

Modifier

Constructor

Description

protected

MessageToByteEncoder()

see MessageToByteEncoder(boolean) with true as boolean parameter.

protected

MessageToByteEncoder (boolean preferDirect)

Create a new instance which will try to detect the types to match out of the type parameter of the class.

protected

MessageToByteEncoder (Class<? extends I> outboundMessageType)

see MessageToByteEncoder(Class, boolean) with true as boolean value.

protected

MessageToByteEncoder (Class<? extends I> outboundMessageType, boolean preferDirect)

Create a new instance
Method Summary

Modifier and Type

Method

Description

boolean

acceptOutboundMessage (Object msg)

Returns true if the given message should be handled.

protected ByteBuf

allocateBuffer (ChannelHandlerContext ctx, I msg, boolean preferDirect)

Allocate a ByteBuf which will be used as argument of encode(ChannelHandlerContext, I, ByteBuf).

protected abstract void

encode (ChannelHandlerContext ctx, I msg, ByteBuf out)

Encode a message into a ByteBuf.

protected boolean

isPreferDirect()

void

write (ChannelHandlerContext ctx, Object msg, ChannelPromise promise)

Calls ChannelOutboundInvoker.write(Object, ChannelPromise) to forward to the next ChannelOutboundHandler in the ChannelPipeline.

Methods inherited from class ChannelOutboundHandlerAdapter
bind, close, connect, deregister, disconnect, flush, read

Methods inherited from class ChannelHandlerAdapter
ensureNotSharable, exceptionCaught, handlerAdded, handlerRemoved, isSharable

Methods inherited from class Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface ChannelHandler
exceptionCaught, handlerAdded, handlerRemoved

Constructor Details
- MessageToByteEncoder
  
  protected MessageToByteEncoder()
  
  see MessageToByteEncoder(boolean) with true as boolean parameter.
- MessageToByteEncoder
  
  protected MessageToByteEncoder(Class<? extends I> outboundMessageType)
  
  see MessageToByteEncoder(Class, boolean) with true as boolean value.
- MessageToByteEncoder
  
  protected MessageToByteEncoder(boolean preferDirect)
  
  Create a new instance which will try to detect the types to match out of the type parameter of the class.
  
  Parameters:
  
  preferDirect - true if a direct ByteBuf should be tried to be used as target for the encoded messages. If false is used it will allocate a heap ByteBuf, which is backed by an byte array.
- MessageToByteEncoder
  
  protected MessageToByteEncoder(Class<? extends I> outboundMessageType, boolean preferDirect)
  
  Create a new instance
  
  Parameters:
  
  outboundMessageType - The type of messages to match
  
  preferDirect - true if a direct ByteBuf should be tried to be used as target for the encoded messages. If false is used it will allocate a heap ByteBuf, which is backed by an byte array.
Method Details
- acceptOutboundMessage
  
  public boolean acceptOutboundMessage(Object msg) throws Exception
  
  Returns true if the given message should be handled. If false it will be passed to the next ChannelOutboundHandler in the ChannelPipeline.
  
  Throws:
  
  Exception
- write
  
  public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception
  
  Description copied from class: ChannelOutboundHandlerAdapter
  
  Calls ChannelOutboundInvoker.write(Object, ChannelPromise) to forward to the next ChannelOutboundHandler in the ChannelPipeline. Sub-classes may override this method to change behavior.
  
  Specified by:
  
  write in interface ChannelOutboundHandler
  
  Overrides:
  
  write in class ChannelOutboundHandlerAdapter
  
  Parameters:
  
  ctx - the ChannelHandlerContext for which the write operation is made
  
  msg - the message to write
  
  promise - the ChannelPromise to notify once the operation completes
  
  Throws:
  
  Exception - thrown if an error occurs
- allocateBuffer
  
  protected ByteBuf allocateBuffer(ChannelHandlerContext ctx, I msg, boolean preferDirect) throws Exception
  
  Allocate a ByteBuf which will be used as argument of encode(ChannelHandlerContext, I, ByteBuf). Sub-classes may override this method to return ByteBuf with a perfect matching initialCapacity.
  
  Throws:
  
  Exception
- encode
  
  protected abstract void encode(ChannelHandlerContext ctx, I msg, ByteBuf out) throws Exception
  
  Encode a message into a ByteBuf. This method will be called for each written message that can be handled by this encoder.
  
  Parameters:
  
  ctx - the ChannelHandlerContext which this MessageToByteEncoder belongs to
  
  msg - the message to encode
  
  out - the ByteBuf into which the encoded message will be written
  
  Throws:
  
  Exception - is thrown if an error occurs
- isPreferDirect
  
  protected boolean isPreferDirect()

Class MessageToByteEncoder<I>

Nested Class Summary

Nested classes/interfaces inherited from interface ChannelHandler

Constructor Summary

Method Summary

Methods inherited from class ChannelOutboundHandlerAdapter

Methods inherited from class ChannelHandlerAdapter

Methods inherited from class Object

Methods inherited from interface ChannelHandler

Constructor Details

MessageToByteEncoder

MessageToByteEncoder

MessageToByteEncoder

MessageToByteEncoder

Method Details

acceptOutboundMessage

write

allocateBuffer

encode

isPreferDirect