端口号出现问题，报错

java.net.BindException: Address already in use: JVM_Bind at java.net.DualStackPlainSocketImpl.bind0(Native Method) at java.net.DualStackPlainSocketImpl.socketBind(DualStackPlainSocketImpl.java:106) at java.net.AbstractPlainSocketImpl.bind(AbstractPlainSocketImpl.java:376) at java.net.PlainSocketImpl.bind(PlainSocketImpl.java:190) at java.net.ServerSocket.bind(ServerSocket.java:376) at java.net.ServerSocket.<init>(ServerSocket.java:237) at java.net.ServerSocket.<init>(ServerSocket.java:128) at Server.main(Server.java:22)