android判断文件是否存在

1. public boolean fileIsExists(){
   
2.                 try{
   
3.                         File f=new File("/mnt/sdcard/update/up.zip");//文件绝对路径
   
4.                         if(!f.exists()){
   
5.                                 return false;
   
6.                         }
   
7.                        
   
8.                 }catch (Exception e) {
   
9.                         // TODO: handle exception
   
10.                         return false;
    
11.                 }
    
12.                 return true;
    
13.         }