MYECLIPSE development environment, hint String cannot is resolved to a type

Download the project from SVN, all the code has come down, locally compiled, Java class always reported n more Red fork, miserable, String cannot be resolved to a type all come out, thought is the jar package is not loaded, So Project-properties--java build path-Libraries, delete the existing jar package, go to workspace under Reload Jar package, No.

Project-properties--java complier-configure Workspace Settings The JDK version is replaced by the default of 1.6 with 1.5. No.

There is a lack of the JRE System Library on the Internet, I am not missing

But after viewing the JRE System library[1.6.0_05] behind Unbond, click Jdk1 next to Edit,alternate JRE. 6 have Red Fork, choose JDK Directory, recompile no problem. This should be an issue where the JDK is not bound

Although the problem is solved, but think it should be the problem of the environment, do not want to understand

This article from Csdn Blog, reproduced please indicate the source: http://blog.csdn.net/qingwangyoucao/archive/2010/09/16/5888494.aspx