如何在Android中登录时管理用户级别/用户类型

Question

正在开发一个具有三个不同级别用户的Android应用程序，即管理员，经理和工程师。我想知道如何在登录活动类中编码，因为在sqlite数据库中有一个包含用户名，密码和用户级别字段的登录表。

活动类的代码段如下：

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.fragment_main);

 // create a instance of SQLite Database
    loginDataBaseAdapter=new LoginDataBaseAdapter(this);
    loginDataBaseAdapter=loginDataBaseAdapter.open();

    // Get The Reference Of Buttons
    setBtnLogin((Button)findViewById(R.id.btnLogin));

}
// Methods to handleClick Event of Sign In Button
public void sendMessage(View view)
   {
        Intent intentLogin=new Intent(getApplicationContext(),MainActivity.class);
        startActivity(intentLogin);

        final Dialog dialog = new Dialog(MainActivity.this);
        dialog.setContentView(R.layout.fragment_main);
        dialog.setTitle("Login");

        // get the References of views
        final  EditText username=(EditText)dialog.findViewById(R.id.reg_username);
        final  EditText password=(EditText)dialog.findViewById(R.id.reg_password);

        Button btnLogin=(Button)dialog.findViewById(R.id.btnLogin);

        // Set On ClickListener
        btnLogin.setOnClickListener(new View.OnClickListener() {

            public void onClick(View view) {
                // get The User name and Password
                String userName=username.getText().toString();
                String passWord=password.getText().toString();

                // fetch the Password form database for respective user name
                String storedPassword=loginDataBaseAdapter.getSingleEntry(userName);

                // check if the Stored password matches with  Password entered by user
                if(passWord.equals(storedPassword))
                {
                    Toast.makeText(MainActivity.this, "Congrats: Login Successfull", Toast.LENGTH_LONG).show();
                    dialog.dismiss();
                }
                else
                {
                    Toast.makeText(MainActivity.this, "User Name or Password does not match", Toast.LENGTH_LONG).show();
                }
            }
        });

        dialog.show();

        finish();
        onDestroy();       
   }

@Override
protected void onDestroy() {
    super.onDestroy();
    // Close The Database
    loginDataBaseAdapter.close();
}