project 右键-->properties --> java buil path --> libraries --> 展开要设置源代码的jar --> 选中“Source Attachment:(none)”-->edit -->选中源代码所在位置 -->点 OK
project 右键-->properties --> java buil path --> libraries --> 展开要设置源代码的jar --> 选中“Source Attachment:(none)”-->edit -->选中源代码所在位置 -->点 OK