application不能运行，console显示

The connection to adb is down, and a severe error has occured. 
You must restart adb and Eclipse. 
Please ensure that adb is correctly located at 'XXXX' and can be executed. 

我出错的原因是下载了2个adt包，环境变量和使用的eclipse地址不在一个包下。

用对应的程序就没错了。