Question

下面是服务器端代码。实现简单的replayingDecoder将传入消息分为多段我想将其用作以下处理程序中业务逻辑的预处理器。

但是，在TestReplayingDecoder中完成解码后，不会执行anotherHandler的channRead方法仅执行channelReadComplete方法。为什么？

类似地，当您使用checkPoint和state实现ReplayingDecode时，我已经确认以下处理程序的channelRead可以正常工作。

.childHandler(new ChannelInitializer<SocketChannel>() {
                    @Override
                    protected void initChannel(SocketChannel ch) throws Exception {
                        ChannelPipeline pipeline = ch.pipeline();
                        pipeline.addLast(new LoggingHandler(LogLevel.INFO));
                        pipeline.addLast(new TestReplayingDecoder());
                        pipeline.addLast(new AnotherHandler());
                    }
                });



@Slf4j
public class TestReplayingDecoder extends ReplayingDecoder<Void> {
    @Override
    protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception {
        out.add(in.readBytes(in.readInt()));
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        cause.printStackTrace();
        ctx.close();
    }
}



@Slf4j
@Sharable
public class AnotherHandler extends ChannelInboundHandlerAdapter {

    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
        ctx.writeAndFlush(Unpooled.EMPTY_BUFFER);
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        cause.printStackTrace();
        ctx.close();
    }

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        String msgString = (String) msg;
        ctx.writeAndFlush(Unpooled.copiedBuffer(makeResponse(msg), CharsetUtil.US_ASCII));
    }
}

log ==================

nioEventLoopGroup-2-1 [-:-] [id: 0x2e31ca6f, L:/0:0:0:0:0:0:0:0:21103] READ: [id: 0x653410de, L:/127.0.0.1:21103 - R:/127.0.0.1:61671]
nioEventLoopGroup-2-1 [-:-] [id: 0x2e31ca6f, L:/0:0:0:0:0:0:0:0:21103] READ COMPLETE
nioEventLoopGroup-3-2 [-:-] [id: 0x653410de, L:/127.0.0.1:21103 - R:/127.0.0.1:61671] REGISTERED
nioEventLoopGroup-3-2 [-:-] [id: 0x653410de, L:/127.0.0.1:21103 - R:/127.0.0.1:61671] ACTIVE
nioEventLoopGroup-3-2 [-:-] AnotherHandler.channelActive !!
nioEventLoopGroup-3-2 [-:-] [id: 0x653410de, L:/127.0.0.1:21103 - R:/127.0.0.1:61671] READ: 1024B
         +-------------------------------------------------+
         |  0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f |
+--------+-------------------------------------------------+----------------+
|00000000| 32 39 36 36 41 42 41 30 37 41 52 50 30 32 30 30 |.                |
~ ~
+--------+-------------------------------------------------+----------------+
nioEventLoopGroup-3-2 [-:-] TestReplayingDecoder.decode !!
nioEventLoopGroup-3-2 [-:-] [id: 0x653410de, L:/127.0.0.1:21103 - R:/127.0.0.1:61671] READ: 1024B
         +-------------------------------------------------+
         |  0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f |
+--------+-------------------------------------------------+----------------+
|00000000| 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 |                |
~ ~ 
+--------+-------------------------------------------------+----------------+
nioEventLoopGroup-3-2 [-:-] TestReplayingDecoder.decode !!
nioEventLoopGroup-3-2 [-:-] [id: 0x653410de, L:/127.0.0.1:21103 - R:/127.0.0.1:61671] READ: 922B
         +-------------------------------------------------+
         |  0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f |
+--------+-------------------------------------------------+----------------+
|00000000| 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 |                |
~ ~ 
+--------+-------------------------------------------------+----------------+
nioEventLoopGroup-3-2 [-:-] TestReplayingDecoder.decode !!
nioEventLoopGroup-3-2 [-:-] [id: 0x653410de, L:/127.0.0.1:21103 - R:/127.0.0.1:61671] READ COMPLETE
nioEventLoopGroup-3-2 [-:-] AnotherHandler.channelReadComplete !!
nioEventLoopGroup-3-2 [-:-] [id: 0x653410de, L:/127.0.0.1:21103 - R:/127.0.0.1:61671] WRITE: 0B
nioEventLoopGroup-3-2 [-:-] [id: 0x653410de, L:/127.0.0.1:21103 - R:/127.0.0.1:61671] FLUSH

Answer 1

我非常确定您的channelRead(...)方法已被调用，但是当您尝试将msg转换为ClassCastException时，它将导致String，而它将是一个ByteBuf当您在ByteBuf中产生TestReplayingDecoder时。

ReplayingDecoder想要收集多个传入消息并将它们传递给下一个处理程序

1 个答案: