报错：
java.io.IOException: Connection reset by peer
at sun.nio.ch.FileDispatcherImpl.read0(Native Method)
at sun.nio.ch.SocketDispatcher.read(SocketDispatcher.java:39)
at sun.nio.ch.IOUtil.readIntoNativeBuffer(IOUtil.java:223)
at sun.nio.ch.IOUtil.read(IOUtil.java:197)
at sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:380)
at org.apache.tomcat.util.net.NioChannel.read(NioChannel.java:147)
at org.apache.tomcat.util.net.NioEndpoint$NioSocketWrapper.fillReadBuffer(NioEndpoint.java:1287)
at org.apache.tomcat.util.net.NioEndpoint$NioSocketWrapper.read(NioEndpoint.java:1223)
at org.apache.tomcat.websocket.server.WsFrameServer.onDataAvailable(WsFrameServer.java:72)
at org.apache.tomcat.websocket.server.WsFrameServer.doOnDataAvailable(WsFrameServer.java:171)
at org.apache.tomcat.websocket.server.WsFrameServer.notifyDataAvailable(WsFrameServer.java:151)
at org.apache.tomcat.websocket.server.WsHttpUpgradeHandler.upgradeDispatch(WsHttpUpgradeHandler.java:148)
at org.apache.coyote.http11.upgrade.UpgradeProcessorInternal.dispatch(UpgradeProcessorInternal.java:54)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:53)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:808)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1498)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
原因是
1，如果一端的Socket被关闭（或主动关闭，或因为异常退出而 引起的关闭），另一端仍发送数据，发送的第一个数据包引发该异常(Connect reset by peer)。
Socket默认连接60秒，60秒之内没有进行心跳交互，即读写数据，就会自动关闭连接。
2，一端退出，但退出时并未关闭该连接，另一端如果在从连接中读数据则抛出该异常（Connection reset）。