Android ContentResolver读取短信并自动填充

SMSContent类
import android.content.Context;
import android.database.ContentObserver;
import android.database.Cursor;
import android.net.Uri;
import android.os.Handler;
import android.widget.TextView;

public class SMSContent extends ContentObserver {
//上下文
private Context context;
//被填充的textView
private TextView textView;

public SMSContent(Handler handler, Context context, TextView textView) {
    super(handler);
    this.context = context;
    this.textView = textView;
}

//重写onChange方法
@Override
public void onChange(boolean selfChange) {
    super.onChange(selfChange);
    /***
     * 查询短信的数据库并排序
     * _id id
     * address 发信人
     * body 信息内容
     */
    Cursor cursor = context.getContentResolver().query(Uri.parse("content://sms/inbox"),
            new String[]{"_id", "address", "body"},
            null, null, "_id desc");
    if (cursor != null && cursor.getCount() > 0) {
        //获得第一条短信的信息
        cursor.moveToFirst();
        String body = cursor.getString(cursor.getColumnIndex("body"));
        //设置给textView
        textView.setText(body);
    }
}

}

MainActivity类
import android.Manifest;
import android.content.pm.PackageManager;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.os.Handler;
import android.widget.TextView;

import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;

public class MainActivity extends AppCompatActivity {

private TextView textView;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    //初始化控件
    textView = findViewById(R.id.textView);
    //获取权限
    getAccess(Manifest.permission.READ_SMS);
    //注册监听
    SMSContent smsContent = new SMSContent(new Handler(), this, textView);
    this.getContentResolver().registerContentObserver(Uri.parse("content://sms"), true, smsContent);
}

private void getAccess(String permission) {
    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M)
        return;
    if (ContextCompat.checkSelfPermission(getApplication(), permission) == PackageManager.PERMISSION_GRANTED)
        return;
    ActivityCompat.requestPermissions(this, new String[]{permission}, 1);
}

}