今天在測試HTTPURLConnection時報了一個這樣的錯：
1 java.net.ConnectException: Connection refused: connect 2 at java.net.PlainSocketImpl.socketConnect(Native Method) 3 at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333) 4 at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:195) 5 at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182) 6 at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366) 7 at java.net.Socket.connect(Socket.java:525) 8 at java.net.Socket.connect(Socket.java:475) 9 at sun.net.NetworkClient.doConnect(NetworkClient.java:163) 10 at sun.net.www.http.HttpClient.openServer(HttpClient.java:394) 11 at sun.net.www.http.HttpClient.openServer(HttpClient.java:529) 12 at sun.net.www.http.HttpClient.<init>(HttpClient.java:233) 13 at sun.net.www.http.HttpClient.New(HttpClient.java:306) 14 at sun.net.www.http.HttpClient.New(HttpClient.java:323) 15 at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(HttpURLConnection.java:860) 16 at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:801) 17 at sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:726) 18 at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1049) 19 at java.net.URL.openStream(URL.java:1010)
經檢查發現是端口號不對，我項目是8022，而我寫成了8080；
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補充：以上情況出現在服務器正常運行的情況下，如果服務器沒有開啟，也會出現這種問題。
不光是端口不對，也可能ip地址啊，請求的服務不對啊，等等。。。。。。。。。。。。。。。。。。。。。。