java套接字服务器和嵌入式设备 - 无法正确处理断开连接

I'm writing a server that is supposed to communicate with some embedded devices. The communication protocol is based on a fixed length header. The problem is I can't get my server to handle sudden disconnects of the devices properly (by "sudden" I mean situations when I just turn the device off). Here is the code for the client thread main loop:I'm writing a server that is supposed to commun