In intelliJ/Eclipse is there away to never open files from bin or target or build? or warn?

I j开发者_JAVA技巧ust lost another 20 minutes because my IDE (sometimes I use IntelliJ, sometimes I use Eclipse) opened a file that was from the "bin, target, or build" folder... and I mistakenly thought it was from the src folder.

As I developer I almost always want the source code to look at, not build output artifacts... is there away to make the IDE either not present these as choices, or have it warn me visually that the file is not source (like surrounding the editor in a thick band of zebra stripped yellow and black lines? )

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In IDEA output folders are excluded by default and are not visible in the Project View. Navigation to files from excluded folders also will not work. Double check that these folders are marked as Excluded in the Project Structure | Sources tab.

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In Eclipse I use package explorer to navigate between source files, jsp, etc. It does not show any build/target/bin folders and there possibility to configure filters for it (Small down faced arrow next to titlebar)