Expertise: Intermediate
Language: Java

July 2, 2001

Setting Proxy in Java Code

The java.net package contains classes that deal with connections across the network. If there is a direct connection to the Internet via a modem, various classes like the HttpConnection or the raw Connection class can be used to get a connection to a server on the net.

This approach fails if you are going through a proxy server. To tell the JVM a proxy is installed, system variables need to be set explicitly set using the System class.

What you have to do is basically set three variables. These are:

proxySet
proxyPort
proxyHost

This small piece of code shows how to set a proxy before calling the connecting code:

//some previous code
System.getProperties().put(“proxySet”,”true”);
System.getProperties().put(“proxyPort”,”8080”);
System.getProperties().put(“proxyHost”,”host”);
try
{
URL validateURL = new URL(“www.foo.com?name=Irfan”);
URLConnection connection = validateURL.openConnection();
//Do some thing with the connection
}
catch(Exception e)
{
//Show the Exception
}
//Rest of the stuff....