java ftp相关的异常汇总

1、SSL:javax.net.ssl.SSLException: Inbound closed before receiving peer's close_notify: possible trunca

javax.net.ssl.SSLException: Inbound closed before receiving peer's close_notify: possible truncation attack?
at sun.security.ssl.Alerts.getSSLException(Alerts.java:208) ~[na:1.7.0_45]
at sun.security.ssl.SSLEngineImpl.fatal(SSLEngineImpl.java:1619) ~[na:1.7.0_45]
at sun.security.ssl.SSLEngineImpl.fatal(SSLEngineImpl.java:1587) ~[na:1.7.0_45]
at sun.security.ssl.SSLEngineImpl.closeInbound(SSLEngineImpl.java:1517) ~[na:1.7.0_45]
at org.jboss.netty.handler.ssl.SslHandler.channelDisconnected(SslHandler.java:672) ~[netty-3.8.0.Final.jar:na]
at org.jboss.netty.channel.Channels.fireChannelDisconnected(Channels.java:396) ~[netty-3.8.0.Final.jar:na]
at org.jboss.netty.channel.socket.nio.AbstractNioWorker.close(AbstractNioWorker.java:360) ~[netty-3.8.0.Final.jar:na]
at org.jboss.netty.channel.socket.nio.NioWorker.read(NioWorker.java:93) ~[netty-3.8.0.Final.jar:na]
at org.jboss.netty.channel.socket.nio.AbstractNioWorker.process(AbstractNioWorker.java:108) ~[netty-3.8.0.Final.jar:na]
at org.jboss.netty.channel.socket.nio.AbstractNioSelector.run(AbstractNioSelector.java:318) ~[netty-3.8.0.Final.jar:na]
at org.jboss.netty.channel.socket.nio.AbstractNioWorker.run(AbstractNioWorker.java:89) ~[netty-3.8.0.Final.jar:na]
at org.jboss.netty.channel.socket.nio.NioWorker.run(NioWorker.java:178) ~[netty-3.8.0.Final.jar:na]

在网上查找资料后发现了原因：

"It's not actually a bug. An SSLException can be sometimes thrown while destroying the session if the connection was closed abnormally. You can simply ignore that exception. That's why I logged that message in DEBUG level."

It's probably because the remote peer is closing the connection immediately not sending the last close_notify. Actually sending close_notify message is not madatory in SSL, so it's OK IMO. But as you pointed out, it's somewhat annoying. I don't have clear solution for this for now. Any patch is welcome.

浏览器客户端关闭SSL连接时，没有发送close_notify message到服务器，导致服务器报错。该错不会影响系统运行。

解决方法：

将日志级别从debug提升到INFO即可。