Tag: proxy

Using a http proxy from a Mendix Java action

As part of some work I have been undertaking to integrate the UK Government Notifications service into Mendix, I needed to be able to make API calls from behind a firewall using a proxy in a Java action.

Due to the lower level Java actions in Mendix run at, proxy settings are not automatically applied, and must be added manually. I wanted to explain how to get the proxy settings from Mendix, and use them a Java action.

I’ve previously explained how to add proxy settings to Mendix, so I assume this step has been completed.

In a Java action, we need to get these from the HttpConfiguration singleton.

import com.mendix.http.HttpConfiguration;
import com.mendix.http.IHttpConfiguration;
import com.mendix.http.IProxyConfiguration;

IHttpConfiguration httpconf = com.mendix.http.HttpConfiguration.getInstance();
IProxyConfiguration proxyconf = httpconf.getProxyConfiguration().orElse(null);

We can now check if we have a proxy configuration set, if we don’t proxyconf will be null.

The username and password for the proxy can be retrieved using the getUser() and getPassword() methods.

String username = proxyconf.getUser().orElse(null);
String password = proxyconf.getPassword().orElse(null);

If they are present we can build a Java Authenticator object and set it as the default authenticator. 

import java.net.Authenticator;
import java.net.PasswordAuthentication;

if (username != null && password != null) {
    Authenticator authenticator = new Authenticator() {
        public PasswordAuthentication getPasswordAuthentication() {
           return (new PasswordAuthentication(username, password.toCharArray()));
        }
    };

    Authenticator.setDefault(authenticator);
}

Next we need to create the Proxy object. We need to get the host and port of our proxy server from Mendix using the getHost() and getPort() methods.

import java.net.InetSocketAddress;
import java.net.Proxy;

InetSocketAddress proxyLocation = new InetSocketAddress(proxyconf.getHost(), proxyconf.getPort());
Proxy proxy = new Proxy(Proxy.Type.HTTP, proxyLocation);

The proxy can be used for Java network actions.

An example of using this would be the UK Government Notifications client. It has a second optional paramater in it’s constructor for a Proxy.

client = new NotificationClient('APIKey', proxy);

Using a proxy server from the Mendix Modeller

There are times when building online services you find yourself behind a firewall and need to use a proxy. Sometimes these are transparent, but other times you need to add settings by hand.

In a Mendix app, an example may be when you need to consume a REST service from outside you home network.

To configure proxy settings in Mendix, you need to go to our Project’s “Settings”. Open “Configurations”, select your working configuration, and click “Edit”. Select the “Custom” tab and add the following “Names” and “Values”.

http.proxyHost The name your proxy
http.proxyPort The port your proxy is running off of.

If my proxy was running on proxy.robertprice.co.uk:8080, my settings would be

http.proxyHost proxy.robertprice.co.uk
http.proxyPort 8080

Sometimes the proxy will also need a username and password. You can set these using http.proxyUser and http.proxyPassword. For example

http.proxyUser RobertPrice
http.proxyPassword SecretPassword

You should now be able to access external services through the proxy from Mendix.

Example proxy settings for the Mendix Modeller

More information on using a proxy in Mendix is available at Using a proxy to call a REST service.

Using Disqus On WordPress Behind A Proxy

I had to implement the Disqus Comment System WordPress plugin on a website that will be located behind an outgoing proxy server. By default the Disqus WordPress plugin does not support proxies, so it is unable to run if a proxy is blocking it’s access to the internet.

Since WordPress 2.8, WordPress supports proxy servers using a few defined values, WP_PROXY_HOST and WP_PROXY_PORT. I have now forked the Disqus WordPress plugin on GitHub, and added support that will look to see if these exist, and use them if they do.

To use it, add the following to your wp-config.php file…

define('WP_PROXY_HOST', 'proxy.yourdomain.com');
define('WP_PROXY_PORT', '3128');

Changing the values to match those of your proxy server of course.

Now replace the url.php file in wp-content/plugins/disqus-comment-system/lib/api/disqus/url.php with the url.php found in my github repository.

Visit your WordPress admin panel and you should now be able to activate and configure the Disqus plugin successfully.

I have issued a pull request for my changes to be pulled back into the main plugin, but it’s up to Disqus is they want to implement this or not.