(1) JDK mismatch (or non-existent)
The JDK specified by the project is "jdk1.6.0_18", while current eclipse is using "jdk1.6.0_22". Need to be in BuildPath | Libraries, make simple adjustments in.
(2) Missing or conflicting jar packages
This error is reported when the jar containing the "XX" is not found. Resolve only need to find (CTRL + click, may see the jar package name) corresponding to the Jar package import project.
In addition, this error will also be reported when the same xx appears. You may need to swap, unpack, or delete.
(3)
It is possible that the constructor is not written in the class, (both the non-argument and the reference are written)
(4) Eclipse Find project type policy caused
Eclipse, the above two have been compared, there is no problem, but also reported this mistake. At this point, you need to work on Project | Clean ..., the problem can be solved. The reason is that the mechanism is responsible. For some special reasons, Eclipse failed to automatically compile the source code into build/classes (or other classes directories), causing the type to not be found.
"XX cannot is resolved to a type" eclipse error and resolution instructions