mina 丢包的问题 - ITeye问答

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mina 丢包的问题5

项目中一直存在这样一个问题：在某个时刻，就会报这样的错

org.apache.mina.filter.codec.ProtocolDecoderException: java.lang.IllegalArgumentException: capacity: -12 (Hexdump: 00 00 00 00 00 00 00 00 01 AF 4B 00 01 02 00 00 00 08 01 00 00 00 01 01 00 00 01 6B 00 00 00 A5 10 10 10 15 1A F4 BA 88 01 03 00 01 AF 4B 01 00 04 33 30 30 39 00 00 00 2B 00 00 00 0D 02 01 00 00 02 24 00 00 06 A8 00 00 00 00 00 00 01 63 00 00 00 49 00 00 00 04 00 00 00 AA 00 00 00 00 00 00 00 2C 00 00 00 00 00 00 03 93 00 00 03 C3 00 00 00 50 00 00 00 3C 00 00 00 1B 00 00 00 1B 00)
at org.apache.mina.filter.codec.ProtocolCodecFilter.messageReceived(ProtocolCodecFilter.java:251)
at org.apache.mina.core.filterchain.DefaultIoFilterChain.callNextMessageReceived(DefaultIoFilterChain.java:434)
at org.apache.mina.core.filterchain.DefaultIoFilterChain.access$1200(DefaultIoFilterChain.java:46)
at org.apache.mina.core.filterchain.DefaultIoFilterChain$EntryImpl$1.messageReceived(DefaultIoFilterChain.java:796)
at org.apache.mina.filter.logging.LoggingFilter.messageReceived(LoggingFilter.java:284)
at org.apache.mina.core.filterchain.DefaultIoFilterChain.callNextMessageReceived(DefaultIoFilterChain.java:434)
at org.apache.mina.core.filterchain.DefaultIoFilterChain.access$1200(DefaultIoFilterChain.java:46)
at org.apache.mina.core.filterchain.DefaultIoFilterChain$EntryImpl$1.messageReceived(DefaultIoFilterChain.java:796)
at org.apache.mina.core.filterchain.IoFilterAdapter.messageReceived(IoFilterAdapter.java:119)
at org.apache.mina.core.filterchain.DefaultIoFilterChain.callNextMessageReceived(DefaultIoFilterChain.java:434)
at org.apache.mina.core.filterchain.DefaultIoFilterChain.fireMessageReceived(DefaultIoFilterChain.java:426)
at org.apache.mina.core.polling.AbstractPollingIoProcessor.read(AbstractPollingIoProcessor.java:693)
at org.apache.mina.core.polling.AbstractPollingIoProcessor.process(AbstractPollingIoProcessor.java:646)
at org.apache.mina.core.polling.AbstractPollingIoProcessor.process(AbstractPollingIoProcessor.java:635)
at org.apache.mina.core.polling.AbstractPollingIoProcessor.access$400(AbstractPollingIoProcessor.java:67)
at org.apache.mina.core.polling.AbstractPollingIoProcessor$Processor.run(AbstractPollingIoProcessor.java:1079)
at org.apache.mina.util.NamePreservingRunnable.run(NamePreservingRunnable.java:64)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:662)
Caused by: java.lang.IllegalArgumentException: capacity: -12
at org.apache.mina.core.buffer.IoBuffer.allocate(IoBuffer.java:224)
at org.apache.mina.core.buffer.IoBuffer.allocate(IoBuffer.java:210)
。。。。。。。。。。。

报错的直接原因是：每读一条消息前面的四个字节是包长，读这条消息时，前四个字节为0，不符合协议规范，就抛错了。
本人用抓包工具，跟踪后发现：实际上网络层接受到的数据是完整的，且符合协议规范。所以这里应该能排出客户端的原因
客户端实际上发来了3条数据，而mina只成功解析了一条，在解析第二条的时候就抛了这样的错误。而第三条消息也包含在了异常打印出的字节里面

诡异的地方是异常所打印出来的16进制，实际上前头还有18个字节不知道丢哪去了。正因为丢了这18个字节，所以才抛了错。
当然这个异常每次出现，所丢的字节数是不确定的。且这个异常复现的时机也不确定。
不知道各位大牛是否遇到过这样的情况？或者能帮我分析分析这报错的真正原因。。。。