The project was not built since its build path is incomplete. Cannot find the class file for java.la

最近把以前windows上的android的代码都放到移动硬盘，然后在mac上运行，因以前都是eclipse开发，

费了半天劲（谷歌不维护了、公司网速慢）弄好了mac版的eclipse

导入代码到eclipse 结果出现下面的错误：

The project was not built since its build path is incomplete. Cannot find the class file for java.lang.Object. Fix the build path then try building this project

The type java.lang.Object cannot be resolved. It is indirectly referenced from required .class files

Unable to resolve target 'android-19' until the SDK is loaded

我的解决方式：

1、删掉workspace项目工程下的.metadata文件，然后重新导入代码

2、右击Build Path；Configure Build Path; Android，选中对应上 如下图，OK搞定