How to Call a web service from behind a firewall/Proxy

[Yogesh Gandhi]

Do I need a different code when I need to call a web service from behind a firewall/Proxy..... Usually in corporate offices we are behind the firewall/Proxy server.

Do I need to pass the proxy settings before calling the web service.

If yes, how do we do that? Any clues?

[David Nicholls]

Hi Yogesh,

the easiest way may be to start your java client using the -D options for the proxy server.

-Dhttps.proxyHost=
-Dhttps.proxyPort=
-Dhttp.proxyHost=
-Dhttp.proxyPort=

[Yogesh Gandhi]

That is the case when we are using a desktop application.

In my case, My class is being executed as a thread along with a web-application.
The thread gets started as soon as the server of the web-application starts.

Now in this case, I don't know how can I give -D option. Can I?

[David Nicholls]

Hi again,

in this case start your servlet container using these flags.

What is your environment? Are you using eclipse? Using tomcat?

Anyway. You may just as well alter your code:
Just put the following static initializer block in your thread class (or any class that is loaded before calling the service).

static {
System.setProperty("https.proxyHost", "IPgoesHere");
System.setProperty("https.proxyPort", "PortGoesHere");
System.setProperty("http.proxyHost", "IPgoesHere");
System.setProperty("http.proxyPort", "PortGoesHere");
}

I recommend starting the JVM using the -D options. Then you don't have to change your code.

[Yogesh Gandhi]

David Nicholls wrote:Hi again,

in this case start your servlet container using these flags.

What is your environment? Are you using eclipse? Using tomcat?

Anyway. You may just as well alter your code:
Just put the following static initializer block in your thread class (or any class that is loaded before calling the service).

static {
System.setProperty("https.proxyHost", "IPgoesHere");
System.setProperty("https.proxyPort", "PortGoesHere");
System.setProperty("http.proxyHost", "IPgoesHere");
System.setProperty("http.proxyPort", "PortGoesHere");
}

I recommend starting the JVM using the -D options. Then you don't have to change your code.

So we are sure on this that if I use -D option I dont need to change my code?

Well in another scenario (Where I had a main program java code)  where I was calling httpURL.openConnection()
I had to use overloaded method httpURL.openConnection(proxy)

and pass a Proxy object in order to make it work. Even though I had it passed as JVM arguments to the main program, this openConnection call still required the proxy object in order to work correctly.

[Tim Holloway]

The "-D" option on the java command line is equivalent to calling System.setProperty() before invoking the main() method.

So a good practice might look like this:

this.proxyIP = System.getProperty("https.proxyHost", "proxyserver.mycompany.com");
this.proxyPort =System.getProperty("https.proxyPort", "8137");

That allows you to code default proxy settings in the application. If, however, you  needed to talk via an alternative proxy server, you could then override on the command line:

java -D https.proxyHost=altproxy.mycompany.com com.mycompany.application6.ApplicationMain