why ConnectException: Connection refused: connect is thrown from HttpURLConnection.getResponseCode()?

Question

Why is ConnectException: Connection refused: connect exception thrown from HttpURLConnection.getResponseCode()?

URL obj = new URL(url);
HttpURLConnection con = (HttpURLConnection) obj.openConnection();
con.setRequestMethod("POST");
con.getResponseCode(); // this line

Exception is:

java.net.ConnectException: Connection refused: connect
at java.net.DualStackPlainSocketImpl.connect0(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
at java.net.AbstractPlainSocketImpl.connect(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 sun.net.NetworkClient.doConnect(Unknown Source)
at sun.net.www.http.HttpClient.openServer(Unknown Source)
at sun.net.www.http.HttpClient.openServer(Unknown Source)
at sun.net.www.http.HttpClient.parseHTTPHeader(Unknown Source)
at sun.net.www.http.HttpClient.parseHTTP(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
at java.net.HttpURLConnection.getResponseCode(Unknown Source)
at com.datasoft.cbsdit.CbsditApplication.main(CbsditApplication.java:30)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:48)
at org.springframework.boot.loader.Launcher.launch(Launcher.java:87)
at org.springframework.boot.loader.Launcher.launch(Launcher.java:50)
at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:51)

Are you sure the remote server you are trying to connect is reachable ? — ali4j, Jul 22 '19 at 07:50
Because nothing was listening at that IP:port. Why are you calling `getResponseCode()` but ignoring the result? — user207421, Jul 22 '19 at 08:05

score 0 · Answer 1 · answered Jul 22 '19 at 08:01

0

Remote machine URL is incorrect or remote server is down, mentioned code works fine, if you try with valid url value (e.g: https://stackoverflow.com) :)

answered Jul 22 '19 at 08:01

Vishal Kumar

53
7

why ConnectException: Connection refused: connect is thrown from HttpURLConnection.getResponseCode()?

1 Answers1