[java] Single Line Warnings #730

Description:

I am running PMD in Eclipse. Some of the warnings are multi-line warnings (e.g. ExcessiveImports). These warnings create a long yellow bar on the right-hand side of the editor. This makes it impossible to see the other markers that this bar is covering. I have to scroll through the file to find the other PMD issues. Please make all warnings only single-line. Thus, there will be a small marker shown in the right-hand side of the editor and all other markers will be visible.

Running PMD through: [Eclipse]

Status overview

-> See https://github.com/pmd/pmd/wiki/Single-Line-Warnings---Report-Locations

Follow-up tasks

• Update rule creation/tests documentation, to have a step to create a test case "Verify location of violation"
• Somehow ensure, that every rule has a test case with that name (maybe via net.sourceforge.pmd.test.lang.rule.AbstractRuleSetFactoryTest)
• Consider to improve pmd-regression-tester to verify start/end line/column. See Add support for comparing entire rule violation location pmd-regression-tester#148
• This issue is for java only. But we should do this for other languages as well. Create separate issues.