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java - 使用Netty Demo报错

public class TimeServer {
    public void bind(int port) {
        try {
            EventLoopGroup bossGroup = new NioEventLoopGroup();
            EventLoopGroup workGroup = new NioEventLoopGroup();
            ServerBootstrap b = new ServerBootstrap();
            b.group(bossGroup, workGroup).channel(NioServerSocketChannel.class).option(ChannelOption.SO_BACKLOG, 1024)
            .childHandler(new ChannelInitializer<SocketChannel>() {
                @Override
                protected void initChannel(SocketChannel arg0) throws Exception {
                    System.out.println("初始化");
                    arg0.pipeline().addLast(new TimeHandler());
                }
            });
            ChannelFuture future = b.bind(port).sync();
            System.out.println("执行这里");
            future.channel().closeFuture().sync();
            System.out.println("执行这里");
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
      public static void main(String[] args) {
        new  TimeServer().bind(10000);
    }
}
public class TimeHandler extends ChannelInboundHandlerAdapter {
    

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        super.channelRead(ctx, msg);
    ByteBuf buf=(ByteBuf) msg;
////        byte[] butfs = buf.array();//报错
    System.out.println(buf.readableBytes());
        byte[] butfs = new byte[buf.readableBytes()];
        buf.readBytes(butfs);
        System.out.println(new String(butfs,"UTF-8"));
        System.out.println(msg);
    }


}

客户端使用的是BIO的模型:


public static void main(String[] args) throws Exception {
        final int port = 10000;
//        NioServer server = new NioServer(port);
//        server.init();
        /// ========================================================
        // 接下来模拟3个Client并发访问服务器
        int poolsize = 1;
        ExecutorService pool = Executors.newFixedThreadPool(poolsize);
        Collection<Callable> tasks = new ArrayList<Callable>(10);
        final String clientname = "clientThread";
        for (int i = 0; i < poolsize; i++) {
            final int n = i;
            // 若每一个Client都保持使用BIO方式发送数据到Server,并读取数据。
            tasks.add(new Callable() {
                @Override
                public Object call() throws Exception {
                    Socket socket = new Socket("127.0.0.1", port);
                    final InputStream input = socket.getInputStream();
                    final OutputStream out = socket.getOutputStream();
                    final String clientname_n = clientname + "_" + n;
                    // BIO读取数据线程
                    new Thread(clientname_n + "_read") {
                        @Override
                        public void run() {
                            byte[] bs = new byte[1024];
                            while (true) {
                                try {

                                    Thread.sleep(1000);

                                } catch (InterruptedException e) {
                                    e.printStackTrace();
                                }
                                int len = 0;
                                try {
                                    while ((len = input.read(bs)) != -1) {

                                        System.out.println("Clinet thread " + Thread.currentThread().getName()
                                                + " read: " + new String(bs, 0, len));
                                    }

                                } catch (IOException e) {

                                    e.printStackTrace();
                                }
                            }
                        }

                    }.start();
                    // BIO写数据线程
                    new Thread(clientname_n + "_write") {
                        @Override
                        public void run() {
                            int a = 0;
                            while (true) {
                                try {
                                    Thread.sleep(100);

                                } catch (InterruptedException e) {
                                    e.printStackTrace();
                                }

                                String str = Thread.currentThread().getName() + " hello, " + a;
                                try {
                                    out.write(str.getBytes());
                                    out.flush();
                                    a++;

                                } catch (IOException e) {
                                    e.printStackTrace();
                                }
                            }
                        }

                    }.start();

                    return null;

                }

            });

        }
        pool.invokeAll((Collection<? extends Callable<Object>>) tasks);
//        server.go();

    }

结果运行的时候出现了以下错误:

月 13, 2017 5:52:56 下午 io.netty.channel.DefaultChannelPipeline onUnhandledInboundException
警告: An exceptionCaught() event was fired, and it reached at the tail of the pipeline. It usually means the last handler in the pipeline did not handle the exception.
io.netty.util.IllegalReferenceCountException: refCnt: 0
    at io.netty.buffer.AbstractByteBuf.ensureAccessible(AbstractByteBuf.java:1408)
    at io.netty.buffer.AbstractByteBuf.checkReadableBytes0(AbstractByteBuf.java:1394)
    at io.netty.buffer.AbstractByteBuf.checkReadableBytes(AbstractByteBuf.java:1383)
    at io.netty.buffer.AbstractByteBuf.readBytes(AbstractByteBuf.java:850)
    at io.netty.buffer.AbstractByteBuf.readBytes(AbstractByteBuf.java:858)
    at test.netty.TimeHandler.channelRead(TimeHandler.java:17)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
    at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1334)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
    at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:926)
    at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:134)
    at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:624)
    at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:559)
    at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:476)
    at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:438)
    at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858)
    at io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:144)
    at java.lang.Thread.run(Thread.java:745)

请问这是为什么呢?

大家讲道理大家讲道理2742일 전1079

모든 응답(2)나는 대답할 것이다

  • 巴扎黑

    巴扎黑2017-04-18 10:57:59

    netty4에서는 객체의 수명 주기가 참조 카운터에 의해 제어됩니다. ByteBuf의 경우도 마찬가지입니다. 릴리스 메서드가 한 번 호출되면 참조 카운터가 감소합니다. by 1. 카운터가 0인 객체에 접근하려고 하면, verifyAccessible 구현과 마찬가지로 IllegalReferenceCountException이 발생합니다. 자세한 설명은 공식 문서

    를 참조하세요.

    AbstractByteBuf.java

    으아악

    TZ의 TimeHandler 클래스에 있는 super.channelRead(ctx, msg); 코드 줄에 주의하세요. 호출 경로를 추적하세요.

    으아악

    호출된 최종 코드는: ReferenceCountUtil.release(msg)

    으아악

    즉, super.channelRead(ctx, msg);가 호출될 때마다 ByteBuf는 release() 메서드를 호출하고 카운터는 1씩 감소한 다음 buf.readBytes(butfs)에서 이 코드 줄은 다음과 같이 됩니다. verifyAccessible() 을 확인하면 카운터는 0이고 netty는 ByteBuf 객체가 해제되었다고 생각하고 예외를 발생시킵니다.

    해결책:

    TimeHandler super.channelRead(ctx, msg);
    ByteBuf 객체를 처리하는 사람이 이를 해제합니다.

    회신하다
    0
  • PHP中文网

    PHP中文网2017-04-18 10:57:59

    ExceptionCaught() 이벤트가 발생하여 파이프라인 끝에 도달했습니다. 이는 일반적으로 파이프라인의 마지막 처리기가 예외를 처리하지 않았음을 의미합니다.
    缺少ExceptionCaught(),재재서버端最后一个Handler中增加ExceptionCaught()

    회신하다
    0
  • 취소회신하다