To use behind a proxy or firewall, add this to the Run Configurations VM arguments:  

-DproxySet=false -DproxyHost=X.X.X.X -DproxyPort=X

To use Fidder, a tool used to trace HTTP traffic, add this to the Run Configurations VM arguments:

-DproxySet=true -DproxyHost=localhost -DproxyPort=8888  -Djavax.net.ssl.trustStore="[path_to_jdk]\jre\lib\security\jssecacerts"