From http://stackoverflow.com/questions/9620720/fiddler-not-capturing-http-requests-from-java-application

You can simply set Fiddler as HTTP proxy for your application by setting the properties

http.proxyHost to localhost and http.proxyPort to 8888 for HTTP traffic and https.proxyHost / https.proxyPort for HTTPS traffic.

For HTTPS traffic you also have to add the Fiddler root certificate (exportable in options dialog) as trusted certificate to your application.

You can do so by adding the following lines at the beginning of your code

System.setProperty("http.proxyHost","localhost"); System.setProperty("http.proxyPort","8888");

or set them via command line when starting the Java-VM:

java -Dhttp.proxyHost=localhost -Dhttp.proxyPort=8888...