更新到新的 Mac OS X 再打开Eclipse 编译程序会报错，
Exception in thread "main" java.lang.UnsupportedClassVersionError: Unsupported major.minor version 51.0
原因是Eclipse 找不到新版本的Java Runtime 的路径，需要有人来告诉他，解决办法：
- Launch
Eclipse.app - Choose
Eclipse -> Preferences - Choose
Java -> Installed JREs - Click the
Add...button - Choose
MacOS X VMas the JRE type. Press Next. - In the "JRE Home:" field, type
/Library/Java/JavaVirtualMachines/1.7.0.jdk/Contents/Home - You should see the system libraries in the list titled "JRE system libraries:"
- Give the JRE a name. The recommended name is
JDK 1.7. Click Finish. - Check the checkbox next to the JRE entry you just created. This will cause Eclipse to use it as the default JRE for all new Java projects. Click OK.
- Now, create a new project. For this verification, from the menu, select
File -> New -> Java Project. - In the dialog that appears, enter a new name for your project. For this verification, type Test17Project
- In the JRE section of the dialog, select
Use default JRE (currently JDK 1.7) - Click Finish.