解决Eclipse按下Ctrl+鼠标左键，无法转到类、变量或者方法问题

Eclipse项目中，按下Ctrl键后，鼠标移动到类、方法后可以显示高亮链接，但点击后无法跳转过去。网上查了很多方法都没有解决

最后无意在国外的网站上找到了解决方法，出处：

https://stackoverflow.com/questions/16354028/eclipse-type-hierarchy-not-always-working

原文：

I had this same problem and fixed it by deleting the Eclipse index cache files located in .metadata/.plugins/org.eclipse.jdt.core. Delete all .index files and savedIndexNames.txt. Do this while Eclipse is not running and then restart. This fixed the issue for me.

即先关掉Eclipse，然后将.metadata/.plugins/org.eclipse.jdt.core文件夹中的.index文件和savedIndexNames.txt文件清理掉，最后重新启动Eclipse