To fully take advantage of SonarQube in Eclipse, it is recommended that your project is already being analyzed on a regular basis by SonarQube. Indeed, you'll get features such as only displaying new issues that you have introduced.
However, if you want to give SonarQube in Eclipse a quick try, you just have to first declare your project through the SonarQube web interface.
Setting SonarQube Servers
Go to Window > Preferences > Sonar > Servers.
SonarQube in Eclipse is pre-configured to access a local SonarQube server listening on http://localhost:9000/. You can edit this server, delete it or add a new one.
Linking a Project to One Analyzed on a SonarQube Server
Linking for the first time
Once the SonarQube server is defined, the next step is to link your Eclipse projects with projects defined and analyzed on this SonarQube server.
To do so, right-click on the project in the Project Explorer, and then Configure > Associate with Sonar...:
In the Sonar project text field, start typing the name of the project and select it in the list box:
Click on Finish. Your project is now associated to one analyzed on your SonarQube server. This means that you'll be able to see existing issues for the project in Eclipse, and that when you run a local analysis in Eclipse, it will use the rule profile the project is assigned to in SonarQube rather than the language's default profile.
At any time, it is possible to change the project association.
To do so, right-click on the project in the Project Explorer, and then Sonar > Change project association...:
Unlinking a Project
To do so, right-click on the project in the Project Explorer, and then Sonar > Remove Sonar Nature:
Severity of SonarQube Markers
You can set the severity of SonarQube markers and SonarQube markers for new violations by going to Window > Preferences > Sonar.
You are now all set with configuration and you can start using SonarQube in Eclipse.