android从客户经理获取gmail用户名和密码

import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends Activity {

    private String gmailUser;
    private String gmailPassword;

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

        Button btnGetGmailUserAndPassword = findViewById(R.id.btn_get_gmail_user_and_password);
        btnGetGmailUserAndPassword.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                gmailUser = "user@example.com";
                gmailPassword = "password";
                TextView textView = findViewById(R.id.text_view);
                textView.setText("Gmail User: " + gmailUser + "\n" +
                        "Gmail Password: " + gmailPassword);
            }
        });
    }

    @Override
    protected void onResume() {
        super.onResume();
        Uri uri = Uri.parse("content://com.android.email.provider/email_addresses");
        String selection = "type=address";
        String[] selectionArgs = new String[]{gmailUser};
        Cursor cursor = getContentResolver().query(uri, null, selection, selectionArgs, null);
        if (cursor != null && cursor.moveToFirst()) {
            String email = cursor.getString(cursor.getColumnIndex("address"));
            cursor.close();
            TextView textView = findViewById(R.id.text_view);
            textView.setText("Gmail User: " + email);
        }
    }
}