http://netty.io/netty-all/: Netty is an asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers and clients. (The Netty Project) 
public abstract class io.netty.handler.codec.MessageToByteEncoder<I> extends io.netty.channel.ChannelOutboundHandlerAdapter
  minor version: 0
  major version: 59
  flags: flags: (0x0421) ACC_PUBLIC, ACC_SUPER, ACC_ABSTRACT
  this_class: io.netty.handler.codec.MessageToByteEncoder
  super_class: io.netty.channel.ChannelOutboundHandlerAdapter
{
  private final io.netty.util.internal.TypeParameterMatcher matcher;
    descriptor: Lio/netty/util/internal/TypeParameterMatcher;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL

  private final boolean preferDirect;
    descriptor: Z
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL

  protected void <init>();
    descriptor: ()V
    flags: (0x0004) ACC_PROTECTED
    Code:
      stack=2, locals=1, args_size=1
        start local 0 // io.netty.handler.codec.MessageToByteEncoder this
         0: .line 55
            aload 0 /* this */
            iconst_1
            invokespecial io.netty.handler.codec.MessageToByteEncoder.<init>:(Z)V
         1: .line 56
            return
        end local 0 // io.netty.handler.codec.MessageToByteEncoder this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    2     0  this  Lio/netty/handler/codec/MessageToByteEncoder<TI;>;

  protected void <init>(java.lang.Class<? extends I>);
    descriptor: (Ljava/lang/Class;)V
    flags: (0x0004) ACC_PROTECTED
    Code:
      stack=3, locals=2, args_size=2
        start local 0 // io.netty.handler.codec.MessageToByteEncoder this
        start local 1 // java.lang.Class outboundMessageType
         0: .line 62
            aload 0 /* this */
            aload 1 /* outboundMessageType */
            iconst_1
            invokespecial io.netty.handler.codec.MessageToByteEncoder.<init>:(Ljava/lang/Class;Z)V
         1: .line 63
            return
        end local 1 // java.lang.Class outboundMessageType
        end local 0 // io.netty.handler.codec.MessageToByteEncoder this
      LocalVariableTable:
        Start  End  Slot                 Name  Signature
            0    2     0                 this  Lio/netty/handler/codec/MessageToByteEncoder<TI;>;
            0    2     1  outboundMessageType  Ljava/lang/Class<+TI;>;
    Signature: (Ljava/lang/Class<+TI;>;)V
    MethodParameters:
                     Name  Flags
      outboundMessageType  

  protected void <init>(boolean);
    descriptor: (Z)V
    flags: (0x0004) ACC_PROTECTED
    Code:
      stack=4, locals=2, args_size=2
        start local 0 // io.netty.handler.codec.MessageToByteEncoder this
        start local 1 // boolean preferDirect
         0: .line 72
            aload 0 /* this */
            invokespecial io.netty.channel.ChannelOutboundHandlerAdapter.<init>:()V
         1: .line 73
            aload 0 /* this */
            aload 0 /* this */
            ldc Lio/netty/handler/codec/MessageToByteEncoder;
            ldc "I"
            invokestatic io.netty.util.internal.TypeParameterMatcher.find:(Ljava/lang/Object;Ljava/lang/Class;Ljava/lang/String;)Lio/netty/util/internal/TypeParameterMatcher;
            putfield io.netty.handler.codec.MessageToByteEncoder.matcher:Lio/netty/util/internal/TypeParameterMatcher;
         2: .line 74
            aload 0 /* this */
            iload 1 /* preferDirect */
            putfield io.netty.handler.codec.MessageToByteEncoder.preferDirect:Z
         3: .line 75
            return
        end local 1 // boolean preferDirect
        end local 0 // io.netty.handler.codec.MessageToByteEncoder this
      LocalVariableTable:
        Start  End  Slot          Name  Signature
            0    4     0          this  Lio/netty/handler/codec/MessageToByteEncoder<TI;>;
            0    4     1  preferDirect  Z
    MethodParameters:
              Name  Flags
      preferDirect  

  protected void <init>(java.lang.Class<? extends I>, );
    descriptor: (Ljava/lang/Class;Z)V
    flags: (0x0004) ACC_PROTECTED
    Code:
      stack=2, locals=3, args_size=3
        start local 0 // io.netty.handler.codec.MessageToByteEncoder this
        start local 1 // java.lang.Class outboundMessageType
        start local 2 // boolean preferDirect
         0: .line 85
            aload 0 /* this */
            invokespecial io.netty.channel.ChannelOutboundHandlerAdapter.<init>:()V
         1: .line 86
            aload 0 /* this */
            aload 1 /* outboundMessageType */
            invokestatic io.netty.util.internal.TypeParameterMatcher.get:(Ljava/lang/Class;)Lio/netty/util/internal/TypeParameterMatcher;
            putfield io.netty.handler.codec.MessageToByteEncoder.matcher:Lio/netty/util/internal/TypeParameterMatcher;
         2: .line 87
            aload 0 /* this */
            iload 2 /* preferDirect */
            putfield io.netty.handler.codec.MessageToByteEncoder.preferDirect:Z
         3: .line 88
            return
        end local 2 // boolean preferDirect
        end local 1 // java.lang.Class outboundMessageType
        end local 0 // io.netty.handler.codec.MessageToByteEncoder this
      LocalVariableTable:
        Start  End  Slot                 Name  Signature
            0    4     0                 this  Lio/netty/handler/codec/MessageToByteEncoder<TI;>;
            0    4     1  outboundMessageType  Ljava/lang/Class<+TI;>;
            0    4     2         preferDirect  Z
    Signature: (Ljava/lang/Class<+TI;>;Z)V
    MethodParameters:
                     Name  Flags
      outboundMessageType  
      preferDirect         

  public boolean acceptOutboundMessage(java.lang.Object);
    descriptor: (Ljava/lang/Object;)Z
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // io.netty.handler.codec.MessageToByteEncoder this
        start local 1 // java.lang.Object msg
         0: .line 95
            aload 0 /* this */
            getfield io.netty.handler.codec.MessageToByteEncoder.matcher:Lio/netty/util/internal/TypeParameterMatcher;
            aload 1 /* msg */
            invokevirtual io.netty.util.internal.TypeParameterMatcher.match:(Ljava/lang/Object;)Z
            ireturn
        end local 1 // java.lang.Object msg
        end local 0 // io.netty.handler.codec.MessageToByteEncoder this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lio/netty/handler/codec/MessageToByteEncoder<TI;>;
            0    1     1   msg  Ljava/lang/Object;
    Exceptions:
      throws java.lang.Exception
    MethodParameters:
      Name  Flags
      msg   

  public void write(io.netty.channel.ChannelHandlerContext, java.lang.Object, io.netty.channel.ChannelPromise);
    descriptor: (Lio/netty/channel/ChannelHandlerContext;Ljava/lang/Object;Lio/netty/channel/ChannelPromise;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=4, locals=8, args_size=4
        start local 0 // io.netty.handler.codec.MessageToByteEncoder this
        start local 1 // io.netty.channel.ChannelHandlerContext ctx
        start local 2 // java.lang.Object msg
        start local 3 // io.netty.channel.ChannelPromise promise
         0: .line 100
            aconst_null
            astore 4 /* buf */
        start local 4 // io.netty.buffer.ByteBuf buf
         1: .line 102
            aload 0 /* this */
            aload 2 /* msg */
            invokevirtual io.netty.handler.codec.MessageToByteEncoder.acceptOutboundMessage:(Ljava/lang/Object;)Z
            ifeq 17
         2: .line 104
            aload 2 /* msg */
            astore 5 /* cast */
        start local 5 // java.lang.Object cast
         3: .line 105
            aload 0 /* this */
            aload 1 /* ctx */
            aload 5 /* cast */
            aload 0 /* this */
            getfield io.netty.handler.codec.MessageToByteEncoder.preferDirect:Z
            invokevirtual io.netty.handler.codec.MessageToByteEncoder.allocateBuffer:(Lio/netty/channel/ChannelHandlerContext;Ljava/lang/Object;Z)Lio/netty/buffer/ByteBuf;
            astore 4 /* buf */
         4: .line 107
            aload 0 /* this */
            aload 1 /* ctx */
            aload 5 /* cast */
            aload 4 /* buf */
            invokevirtual io.netty.handler.codec.MessageToByteEncoder.encode:(Lio/netty/channel/ChannelHandlerContext;Ljava/lang/Object;Lio/netty/buffer/ByteBuf;)V
         5: .line 108
            goto 9
      StackMap locals: io.netty.handler.codec.MessageToByteEncoder io.netty.channel.ChannelHandlerContext java.lang.Object io.netty.channel.ChannelPromise io.netty.buffer.ByteBuf java.lang.Object
      StackMap stack: java.lang.Throwable
         6: astore 6
         7: .line 109
            aload 5 /* cast */
            invokestatic io.netty.util.ReferenceCountUtil.release:(Ljava/lang/Object;)Z
            pop
         8: .line 110
            aload 6
            athrow
         9: .line 109
      StackMap locals:
      StackMap stack:
            aload 5 /* cast */
            invokestatic io.netty.util.ReferenceCountUtil.release:(Ljava/lang/Object;)Z
            pop
        10: .line 112
            aload 4 /* buf */
            invokevirtual io.netty.buffer.ByteBuf.isReadable:()Z
            ifeq 13
        11: .line 113
            aload 1 /* ctx */
            aload 4 /* buf */
            aload 3 /* promise */
            invokeinterface io.netty.channel.ChannelHandlerContext.write:(Ljava/lang/Object;Lio/netty/channel/ChannelPromise;)Lio/netty/channel/ChannelFuture;
            pop
        12: .line 114
            goto 15
        13: .line 115
      StackMap locals:
      StackMap stack:
            aload 4 /* buf */
            invokevirtual io.netty.buffer.ByteBuf.release:()Z
            pop
        14: .line 116
            aload 1 /* ctx */
            getstatic io.netty.buffer.Unpooled.EMPTY_BUFFER:Lio/netty/buffer/ByteBuf;
            aload 3 /* promise */
            invokeinterface io.netty.channel.ChannelHandlerContext.write:(Ljava/lang/Object;Lio/netty/channel/ChannelPromise;)Lio/netty/channel/ChannelFuture;
            pop
        15: .line 118
      StackMap locals:
      StackMap stack:
            aconst_null
            astore 4 /* buf */
        end local 5 // java.lang.Object cast
        16: .line 119
            goto 27
        17: .line 120
      StackMap locals:
      StackMap stack:
            aload 1 /* ctx */
            aload 2 /* msg */
            aload 3 /* promise */
            invokeinterface io.netty.channel.ChannelHandlerContext.write:(Ljava/lang/Object;Lio/netty/channel/ChannelPromise;)Lio/netty/channel/ChannelFuture;
            pop
        18: .line 122
            goto 27
      StackMap locals:
      StackMap stack: io.netty.handler.codec.EncoderException
        19: astore 5 /* e */
        start local 5 // io.netty.handler.codec.EncoderException e
        20: .line 123
            aload 5 /* e */
            athrow
        end local 5 // io.netty.handler.codec.EncoderException e
        21: .line 124
      StackMap locals:
      StackMap stack: java.lang.Throwable
            astore 5 /* e */
        start local 5 // java.lang.Throwable e
        22: .line 125
            new io.netty.handler.codec.EncoderException
            dup
            aload 5 /* e */
            invokespecial io.netty.handler.codec.EncoderException.<init>:(Ljava/lang/Throwable;)V
            athrow
        end local 5 // java.lang.Throwable e
        23: .line 126
      StackMap locals:
      StackMap stack: java.lang.Throwable
            astore 7
        24: .line 127
            aload 4 /* buf */
            ifnull 26
        25: .line 128
            aload 4 /* buf */
            invokevirtual io.netty.buffer.ByteBuf.release:()Z
            pop
        26: .line 130
      StackMap locals: io.netty.handler.codec.MessageToByteEncoder io.netty.channel.ChannelHandlerContext java.lang.Object io.netty.channel.ChannelPromise io.netty.buffer.ByteBuf top top java.lang.Throwable
      StackMap stack:
            aload 7
            athrow
        27: .line 127
      StackMap locals: io.netty.handler.codec.MessageToByteEncoder io.netty.channel.ChannelHandlerContext java.lang.Object io.netty.channel.ChannelPromise io.netty.buffer.ByteBuf
      StackMap stack:
            aload 4 /* buf */
            ifnull 29
        28: .line 128
            aload 4 /* buf */
            invokevirtual io.netty.buffer.ByteBuf.release:()Z
            pop
        29: .line 131
      StackMap locals:
      StackMap stack:
            return
        end local 4 // io.netty.buffer.ByteBuf buf
        end local 3 // io.netty.channel.ChannelPromise promise
        end local 2 // java.lang.Object msg
        end local 1 // io.netty.channel.ChannelHandlerContext ctx
        end local 0 // io.netty.handler.codec.MessageToByteEncoder this
      LocalVariableTable:
        Start  End  Slot     Name  Signature
            0   30     0     this  Lio/netty/handler/codec/MessageToByteEncoder<TI;>;
            0   30     1      ctx  Lio/netty/channel/ChannelHandlerContext;
            0   30     2      msg  Ljava/lang/Object;
            0   30     3  promise  Lio/netty/channel/ChannelPromise;
            1   30     4      buf  Lio/netty/buffer/ByteBuf;
            3   16     5     cast  TI;
           20   21     5        e  Lio/netty/handler/codec/EncoderException;
           22   23     5        e  Ljava/lang/Throwable;
      Exception table:
        from    to  target  type
           4     6       6  any
           1    18      19  Class io.netty.handler.codec.EncoderException
           1    18      21  Class java.lang.Throwable
           1    23      23  any
    Exceptions:
      throws java.lang.Exception
    MethodParameters:
         Name  Flags
      ctx      
      msg      
      promise  

  protected io.netty.buffer.ByteBuf allocateBuffer(io.netty.channel.ChannelHandlerContext, I, boolean);
    descriptor: (Lio/netty/channel/ChannelHandlerContext;Ljava/lang/Object;Z)Lio/netty/buffer/ByteBuf;
    flags: (0x0004) ACC_PROTECTED
    Code:
      stack=1, locals=4, args_size=4
        start local 0 // io.netty.handler.codec.MessageToByteEncoder this
        start local 1 // io.netty.channel.ChannelHandlerContext ctx
        start local 2 // java.lang.Object msg
        start local 3 // boolean preferDirect
         0: .line 139
            iload 3 /* preferDirect */
            ifeq 2
         1: .line 140
            aload 1 /* ctx */
            invokeinterface io.netty.channel.ChannelHandlerContext.alloc:()Lio/netty/buffer/ByteBufAllocator;
            invokeinterface io.netty.buffer.ByteBufAllocator.ioBuffer:()Lio/netty/buffer/ByteBuf;
            areturn
         2: .line 142
      StackMap locals:
      StackMap stack:
            aload 1 /* ctx */
            invokeinterface io.netty.channel.ChannelHandlerContext.alloc:()Lio/netty/buffer/ByteBufAllocator;
            invokeinterface io.netty.buffer.ByteBufAllocator.heapBuffer:()Lio/netty/buffer/ByteBuf;
            areturn
        end local 3 // boolean preferDirect
        end local 2 // java.lang.Object msg
        end local 1 // io.netty.channel.ChannelHandlerContext ctx
        end local 0 // io.netty.handler.codec.MessageToByteEncoder this
      LocalVariableTable:
        Start  End  Slot          Name  Signature
            0    3     0          this  Lio/netty/handler/codec/MessageToByteEncoder<TI;>;
            0    3     1           ctx  Lio/netty/channel/ChannelHandlerContext;
            0    3     2           msg  TI;
            0    3     3  preferDirect  Z
    Exceptions:
      throws java.lang.Exception
    Signature: (Lio/netty/channel/ChannelHandlerContext;TI;Z)Lio/netty/buffer/ByteBuf;
    MethodParameters:
              Name  Flags
      ctx           
      msg           
      preferDirect  

  protected abstract void encode(io.netty.channel.ChannelHandlerContext, I, io.netty.buffer.ByteBuf);
    descriptor: (Lio/netty/channel/ChannelHandlerContext;Ljava/lang/Object;Lio/netty/buffer/ByteBuf;)V
    flags: (0x0404) ACC_PROTECTED, ACC_ABSTRACT
    Exceptions:
      throws java.lang.Exception
    Signature: (Lio/netty/channel/ChannelHandlerContext;TI;Lio/netty/buffer/ByteBuf;)V
    MethodParameters:
      Name  Flags
      ctx   
      msg   
      out   

  protected boolean isPreferDirect();
    descriptor: ()Z
    flags: (0x0004) ACC_PROTECTED
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // io.netty.handler.codec.MessageToByteEncoder this
         0: .line 158
            aload 0 /* this */
            getfield io.netty.handler.codec.MessageToByteEncoder.preferDirect:Z
            ireturn
        end local 0 // io.netty.handler.codec.MessageToByteEncoder this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lio/netty/handler/codec/MessageToByteEncoder<TI;>;
}
Signature: <I:Ljava/lang/Object;>Lio/netty/channel/ChannelOutboundHandlerAdapter;
SourceFile: "MessageToByteEncoder.java"