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Click on Run in the Start menu. Open a command window by typing cmd in the box and hitting Enter. In the command window that pops up, type mvn and enter. Maven should bootstrap itself if you have setup everything correctly. If the command is not found, check that the Path variable contains %MAVEN_HOME%/bin.
Setup Netbeans
Go to ? Netbeans Downloads and get the Java version.
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The option -o can be added when you are running without an internet connection.
Netbeans Settings
To fix running Maven TestCases in Netbeans, right-click on the project and go to Properties > Build. Click on Compile. Set Compile on Save to For application execution only.
Increase the VM heap size for the project by going to the project's Properties and under VM Options in Run, put in -Xmx1024m or however much memory is appropriate for your system. The default is usually -Xmx512, which may not be enough for running some tests.