编译android时，遇到报错：
Errors occurred during the build.Errors running builder 'Android Pre Compiler' on project 'XXX'

java.lang.NullPointerException

错误原因：
工程目录下有很多.svn目录

解决方法：

1. Open properties of project in Eclipse then Resources -> Resource filters.
2. Click the "Add..." button -> Check "Exclude all", "Files and folders", "All children". In the text entry box input ".svn" (without quotes).
3. Restart Eclipse.