Eclipse+Maven src/main/java not visible in src folder in Package Explorer

I have solved this issue by below steps:

1. Right click the Maven Project -> Build Path -> Configure Build Path
2. In Order and Export tab, you can see the message like '2 build path entries are missing'
3. Now select 'JRE System Library' and 'Maven Dependencies' checkbox
4. Click OK

Now you can see below in all type of Explorers (Package or Project or Navigator)

src/main/java

src/main/resources

src/test/java

Eclipse filters out folders that are marked as source from the "raw" folder path. That is, they are visible only as source folders:

If you can't see them in either place, then they

• are either filtered out in the settings: check your settings for Package Explorer (the Package Explorer bar, downwards menu arrow -> Filters...)
• or they were created externally and Eclipse haven't noticed them: Refresh your project in this case.
• or they don't exist: right-click on the project, select New->Folder and input the path, e.g. src/test/java (not "Source Folder"). After you use Maven->Update Project... on the project, they will be automatically added as source folders, provided you have the default configuration.

Now, as I said, those folder will only be used as source if you preserved the default configuration in your POM. If you defined other resources and/or testResources, those will be used instead. In general, Eclipse m2e synchronizes Eclipse's project source folder configuration with what's in your POM.

EDIT: maybe this is unclear - see those folders at the top? The ones labeled with the /-separated paths? These are your folders. These are the same folders that you would expect to find in main and test, just represented differently.

I used to get the same problem, but solved it by pointing to the right jre used for the project.

Right click on the project properties java builpath see the jre selected edit it select alternate jre installed jre select the right one ok After changing right click on project>maven>update project

Hope it helps. Attaching screen shot.