Java套接字異常

Question

我試圖用Java編寫一個簡單的客戶端服務器程序：-在同一台機器上同時運行服務器和客戶端代碼...但是在運行時出現錯誤：-

java.net.ConnectException: Connection refused: connect
        at java.net.PlainSocketImpl.socketConnect(Native Method)
        at java.net.PlainSocketImpl.doConnect(Unknown Source)
        at java.net.PlainSocketImpl.connectToAddress(Unknown Source)
        at java.net.PlainSocketImpl.connect(Unknown Source)
        at java.net.SocksSocketImpl.connect(Unknown Source)
        at java.net.Socket.connect(Unknown Source)
        at java.net.Socket.connect(Unknown Source)
        at java.net.Socket.(Unknown Source)
        at java.net.Socket.(Unknown Source)
        at Requester.run(Requester.java:13)
        at Requester.main(Requester.java:68)
Exception in thread "main" java.lang.NullPointerException
        at Requester.run(Requester.java:45)
        at Requester.main(Requester.java:68)

誰能幫忙！

Answer 1

您嘗試連接的端口是否打開？ 是否有活動的防火牆可能阻止請求？