How do I use a proxy server for HTTP requests ?

If you're writing an application, however you'll have to manually specify the proxy server settings.

You can do this when running a Java application, or you can write code that will specify proxy settings automatically for the user.

To specify proxy settings when running an application, use the -D parameter :

jre -DproxySet=true -DproxyHost=myhost -DproxyPort=myport MyApp

Alternately, your application can maintain a configuration file and specify proxy settings before using a URLConnection :

// Modify system properties

Properties sysProperties  =  System.getProperties();

// Specify proxy settings

sysProperties.put("proxyHost", "myhost");

sysProperties.put("proxyPort", "myport");

sysProperties.put("proxySet", "true");