eofexception属于什么异常（EOFError的解决方法）

聊天系统使用WebSocket进行消息传递，应用服务器使用两台做负载均衡，一台Web服务器部署Nginx做代理，登录系统之后总是会报java.io.EOFException异常，异常内容如下，从错误可以看出是WebSocket走了OnError方法，断开了连接，因为是使用的Nginx做代理，怀疑是Nginx将连接断开了，nginx默认60秒断开连接，尝试设置nginx的断连时间更长一点比如1小时。

java.io.EOFException	at org.apache.tomcat.util.net.NioEndpoint$NioSocketWrapper.fillReadBuffer(NioEndpoint.java:1262)	at org.apache.tomcat.util.net.NioEndpoint$NioSocketWrapper.read(NioEndpoint.java:1196)	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$ConnectionHandler.process(AbstractProtocol.java:800)	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1471)	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)	at java.lang.Thread.run(Thread.java:745)

location / {            root   html;            index  index.html index.htm;            proxy_pass http://wslb;            proxy_http_version 1.1;            proxy_read_timeout 3600s;            proxy_set_header Upgrade $http_upgrade;            proxy_set_header Connection "upgrade";         }

重启nginx，观察登录后的WebSocket连接情况，似乎没有再自动断连。