org.apache.mina.filter.codec.ProtocolDecoderException: java.nio.BufferOverflowException解决

 先连续发几十个很小很小的包(<10 byte) 再突然发一个大小64byte的包 这时你会发现mina就会出现以下错误使用mina处理大数据接收时：

org.apache.mina.filter.codec.ProtocolDecoderException: java.nio.BufferOverflowException (Hexdump: 53 53 00 04)
at org.apache.mina.filter.codec.ProtocolCodecFilter.messageReceived(ProtocolCodecFilter.java:242)
at org.apache.mina.core.filterchain.DefaultIoFilterChain.callNextMessageReceived(DefaultIoFilterChain.java:417)
at org.apache.mina.core.filterchain.DefaultIoFilterChain.access$1200(DefaultIoFilterChain.java:47)
at org.apache.mina.core.filterchain.DefaultIoFilterChain$EntryImpl$1.messageReceived(DefaultIoFilterChain.java:765)
at org.apache.mina.core.filterchain.IoFilterAdapter.messageReceived(IoFilterAdapter.java:109)
at org.apache.mina.core.filterchain.DefaultIoFilterChain.callNextMessageReceived(DefaultIoFilterChain.java:417)
at org.apache.mina.core.filterchain.DefaultIoFilterChain.fireMessageReceived(DefaultIoFilterChain.java:410)
at org.apache.mina.core.polling.AbstractPollingIoProcessor.read(AbstractPollingIoProcessor.java:710)
at org.apache.mina.core.polling.AbstractPollingIoProcessor.process(AbstractPollingIoProcessor.java:664)
at org.apache.mina.core.polling.AbstractPollingIoProcessor.process(AbstractPollingIoProcessor.java:653)
at org.apache.mina.core.polling.AbstractPollingIoProcessor.access$600(AbstractPollingIoProcessor.java:67)
at org.apache.mina.core.polling.AbstractPollingIoProcessor$Processor.run(AbstractPollingIoProcessor.java:1124)
at org.apache.mina.util.NamePreservingRunnable.run(NamePreservingRunnable.java:64)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:885)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:907)
at java.lang.Thread.run(Thread.java:619)
Caused by: java.nio.BufferOverflowException
at java.nio.HeapByteBuffer.put(HeapByteBuffer.java:182)
at org.apache.mina.core.buffer.AbstractIoBuffer.put(AbstractIoBuffer.java:625)
at org.apache.mina.core.buffer.AbstractIoBuffer.put(AbstractIoBuffer.java:1329)

经过对mina的分析，这是由对包长度不对做成的(即，我们发的包长是大于64byte的，但他的byteBuffer大小只有64byte，当我们尝试读取第65个byte就会出现这个错误)；

解决方法：

acceptor.getSessionConfig().setReadBufferSize(1024*1024);//发送缓冲区1M

acceptor.getSessionConfig().setReceiveBufferSize(1024*1024);//接收缓冲区1M

实际应用中根据业务数据包设置合理大小就可以了。

另外：buff在解析完毕没有释放也会导致上述问题，因buff没释放导致该问题的解决在此不赘述。