Eclipse not recognizing imports in same project

Question

From time to time, Eclipse (Indigo) complains that certain classes in my projects cannot be resolved to a type . Even it shows the class in popup list, clicking import (see image) does not add the import statement! Even if I add it manually, it doesn't recognize it (and underlines the import package).

• This happens only in certain projects.
• Unresolved types are in the same project! (not in other dependencies)
• cleaning the project does resolve this, but only temporarily.
• My application consists of multi-module maven based projects.
• All projects are maven-based.

Not recognizing imports

Answer 1

右键单击您的项目名称 -> Maven -> 更新项目

Answer 2

对于那些不使用 Maven 的人来说，简单地删除项目（并可能重新克隆它）对我来说可靠地工作。

Answer 3

This just happened to be in Eclipse Neon.2 (2016 release) on a non-Maven project. Refreshing / updating the project did not help, but I was able to fix this without recreating the project:

1. Go to Properties → Build Path → Source
2. Remove all source folders in the build path, click Apply.
3. Add them all back, click Apply.

Answer 4

Right click on the project -> Maven -> Update Project...

Check (Force Update of Snapshots/Releases)