process.getInputStream（）在adb命令上返回null

Question

我正在尝试重新启动下载，但我得到了：

  

尝试调用虚方法＆＃39; java.io.InputStream java.lang.Process.getInputStream（）＆＃39;在空对象引用上

代码：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);


   String[] s ={"adb", "reboot", "download"};
   Process p = null;
   try {
        p = Runtime.getRuntime().exec(s);
    } catch (IOException e) {
        e.printStackTrace();

    }

  BufferedReader bufferedReader = new BufferedReader(
              new InputStreamReader(p.getInputStream()));

}

我试图把代码放到不同的线程中。

为什么process.getInputStream()在null命令上返回adb？

Answer 1

尝试删除Process p = null，并在try正文中实施：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);


   String[] s ={"adb", "reboot", "download"};
   try {
       Process p = Runtime.getRuntime().exec(s);
    } catch (IOException e) {
        e.printStackTrace();

    }

  BufferedReader bufferedReader = new BufferedReader(
              new InputStreamReader(p.getInputStream()));

}