有时候导入maven工程会报空指针异常：
An internal error occurred during: “Updating Maven Project”. java.lang.NullPointerException
在stackoverflow查找的答案：I solved mine by deleting the .settings folder and .project file in the project and then reimporting the project.
意思就是先删掉工程文件下的setting文件和.project文件后，再重新导入工程。