Netty 客户端手动关闭后，服务端报以下错误，该怎么解决？

Question

java.io.IOException: 远程主机强迫关闭了一个现有的连接。

at sun.nio.ch.SocketDispatcher.read0(Native Method)
at sun.nio.ch.SocketDispatcher.read(SocketDispatcher.java:43)
at sun.nio.ch.IOUtil.readIntoNativeBuffer(IOUtil.java:223)
at sun.nio.ch.IOUtil.read(IOUtil.java:192)
at sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:380)
at io.netty.buffer.PooledUnsafeDirectByteBuf.setBytes(PooledUnsafeDirectByteBuf.java:288)
at io.netty.buffer.AbstractByteBuf.writeBytes(AbstractByteBuf.java:1108)
at io.netty.channel.socket.nio.NioSocketChannel.doReadBytes(NioSocketChannel.java:345)
at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:148)
at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:647)
at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:582)
at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:499)
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:461)
at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:884)
at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
at java.lang.Thread.run(Thread.java:748)

Answer 1

　TCP状态进入CLOSE_WAIT时会产生OP_READ事件通知应用层，Netty从socket读取数据时返回-1，close被设为true，进入关闭流程。如果连接允许“半关闭”则产生ChannelInputShutdownEvent事件；否则，关闭当前连接。

通过自定义拦截器，具体就是继承ChannelHandlerAdapter类，实现父类的close方法，添加到ChannelPipeline里时，注意要添加到最前面。