The type XXX cannot be resolved. It is indirectly

在Eclipse中遇到The type XXX cannot be resolved. It is indirectly referenced from required .class files错误.....,查找的解决办法以下:

一: 
It is indirectly referenced from required .class file

缘由：你正要使用的类调用了另外一个类，而这个类又调用了其余类，这种关系可能会有好多层。而在这个调用的过程当中，某个类所在的包的缺失就会形成以上那个错误。

解决方法：导入缺失的包

二:
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

出現以上訊息的缘由是因為你裝了多個版本的jre或jdk的關係。本來Eclipse在创建專案時，會自動參照你的jre路徑，但多個版本就沒辦法了。 
你只能手動创建… 
1. 進入window\preferences\java\Installed JREs 
1)按Add 
2)輸入JRE Name, 例JDK1.5.0.03 
3)JRE home directory, 選擇安裝的路徑 
4)按OK 
2. 進入Project\properties\Java Bulid Path 
1)Add library 
2)選JRE System Library後按Next 
3)選workplace default JRE後按finish...