多线程的第一次运行没问题，第二次就开始报错了

java.net.SocketException: Connection reset

at java.net.SocketInputStream.read(Unknown Source)

at java.net.SocketInputStream.read(Unknown Source)

at sun.nio.cs.StreamDecoder.readBytes(Unknown Source)

at sun.nio.cs.StreamDecoder.implRead(Unknown Source)

at sun.nio.cs.StreamDecoder.read(Unknown Source)

at java.io.InputStreamReader.read(Unknown Source)

at java.io.BufferedReader.fill(Unknown Source)

at java.io.BufferedReader.readLine(Unknown Source)

at java.io.BufferedReader.readLine(Unknown Source)

at com.MyChatSystem.server.Client.main(Client.java:30)