Runtime.getRuntime().exec获取root权限，并执行命令

public String execRootCmd(String cmd) {
    String result = "";
    DataOutputStream dos = null;
    DataInputStream dis = null;

    try {
        Process p = Runtime.getRuntime().exec("su");// 经过Root处理的android系统即有su命令
        dos = new DataOutputStream(p.getOutputStream());
        dis = new DataInputStream(p.getInputStream());

        Log.i(TAG, cmd);
        dos.writeBytes(cmd + "\n");
        dos.flush();
        dos.writeBytes("exit\n");
        dos.flush();
        String line = null;

        BufferedReader br = new BufferedReader(new InputStreamReader(dis));
        while ((line = br.readLine()) != null) {
            Log.d(TAG, "result:" + line);
            result += line;
        }
        p.waitFor();
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        if (dos != null) {
            try {
                dos.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        if (dis != null) {
            try {
                dis.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
    return result;
}