Eclipse project name appears Red Fork

I. Background and reasons

When the project was first added, I used D:\Java\jdk1.7.0_17, and later, because the configuration would switch Tomcat to JBoss, which was a version of JBoss that only supported jdk6, I replaced the "environment variable java_home" with D:\ Java\jdk1.6.0_20, resulting in the project has been reported " Red fork "!

Ii. Solutions

1, re-replace the "environment variable java_home" jdk6 with Jdk7;

2. The JRE environment before the project is inconsistent with the current. Workaround: Right-click the project-->build path-->configure Build path, locate the Libraries tab, locate the "JRE System Library" item at the bottom of the list box, select it and click the "Remove" button , then click the "Add Library" button, and in the pop-up window, select "JRE System Library"--Next-->finish.

Reference Blog: http://blog.csdn.net/hellostory/article/details/5501872