Are you talking about Java Source Code Scanner? If yes. a java code scanner is a just a utility that will help you determine if there are code that is not being used. If your using eclipse like the Fully loaded eclipse, there is simple example of a java code scanner like if you see a yellow underline of your variable that means that it's not being called but it maybe being used as a storage. If you're using IBM RAD 7 or RAD 7.5, you can set the tools to help you trace what are those code that is not used. There is a tool for JSC http://pmd.sourceforge.net/.
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