不能用java程序从控制台中拉出一个字符串

I have the code segment:

我有代码段：

public static void getOS() throws IOException, InterruptedException
   {
       String[] cmd = {"cat", "/etc/*-release"};
       Process proc = rt.exec(cmd);
       VerboseMode.verboseOut(cmd,proc);

       BufferedReader is = new BufferedReader(new InputStreamReader(proc.getInputStream()));
       line = is.readLine();
       OS = line.trim();
   }
public stat