eclipse报错：An error has occurred. See error log for more details. java.lang.NullPointerException

eclipse一直不停的报错：
An error has occurred. See error log for more details.
java.lang.NullPointerException

在"开始"–>“运行”---->"cmd"进入命令提示行后,再进入eclipse安装目录的eclipse文件夹,然后输入“eclipse -clean”即可

可惜这方法治标不治本，我又找到了另外一个办法：
在eclipse中----->window------>preference