DescriptionResourcePathLocationType Java compiler level does not match the version of the installed Java project facet UnknownFaceted Project Problem (Java Version Mismatch)

project 编译问题，需要三处的jdk版本要保持一致，才能编译通过。

1、在项目上右键properties->project Facets->修改右侧的version  保持一致

2、window->preferences->java->Compiler->设置右侧的Compiler compliance level

3、window->preferences->java->Installed JREs->设置或者选择右侧的Installed JREs

以上三处的jdk版本要保持一致，才能编译通过