应用程序卡在serverSocket.accept（）并在第二次调用线程时给出已经使用的绑定异常地址

I have two problems with an app that i have built for socket communication, first I'll try to explain what the app does and then I'll go into the details of those two problems. First I click on a button, which starts a thread, which sends a multicast massage "group address" through a UDP socket. Once any of the devices receive the massage, they will send a response through TCP socket and my device will act as a server to the one that sent the response. So after debugging I found out the first problem which is I have two problems with an app that i have bui