netty : io.netty.handler.codec.TooLongFrameException

• 背景

做netty权威指南的私有协议开发，案例报错如

io.netty.handler.codec.TooLongFrameException: Adjusted frame length exceeds 1048576: 795898487 - discarded
	at io.netty.handler.codec.LengthFieldBasedFrameDecoder.fail(LengthFieldBasedFrameDecoder.java:501)
	at io.netty.handler.codec.LengthFieldBasedFrameDecoder.failIfNecessary(LengthFieldBasedFrameDecoder.java:477)
	at io.netty.handler.co