如何从php到android获取json的COUNT(id)值

<?php
// 连接数据库
$servername = "数据库服务器地址";
$username = "数据库用户名";
$password = "数据库密码";
$dbname = "数据库名称";
$conn = new mysqli($servername, $username, $password, $dbname);

// 检查连接是否成功
if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}

// 执行COUNT(id)查询
$sql = "SELECT COUNT(id) AS count FROM 表名";
$result = $conn->query($sql);

// 检查查询结果
if ($result->num_rows > 0) {
    // 将结果转换为关联数组
    $row = $result->fetch_assoc();
    // 获取COUNT(id)值
    $count = $row["count"];
    // 将COUNT(id)值转换为JSON格式
    $jsonResponse = json_encode(array("count" => $count));
    // 输出JSON响应
    echo $jsonResponse;
} else {
    echo "查询结果为空";
}

// 关闭数据库连接
$conn->close();
?>

import android.os.AsyncTask;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;

import org.json.JSONException;
import org.json.JSONObject;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

public class MainActivity extends AppCompatActivity {

    private static final String TAG = "MainActivity";

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

        // 执行异步任务以获取JSON数据
        new FetchJsonTask().execute("http://example.com/example.php");
    }

    private class FetchJsonTask extends AsyncTask<String, Void, String> {

        @Override
        protected String doInBackground(String... urls) {
            String result = "";
            try {
                URL url = new URL(urls[0]);
                HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                connection.setRequestMethod("GET");
                connection.connect();

                // 读取响应内容
                InputStream inputStream = connection.getInputStream();
                BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
                String line;
                while ((line = bufferedReader.readLine()) != null) {
                    result += line;
                }

                // 关闭流和连接
                bufferedReader.close();
                inputStream.close();
                connection.disconnect();
            } catch (IOException e) {
                Log.e(TAG, "Error: " + e.getMessage());
            }
            return result;
        }

        @Override
        protected void onPostExecute(String result) {
            super.onPostExecute(result);
            try {
                // 解析JSON数据
                JSONObject jsonObject = new JSONObject(result);
                int count = jsonObject.getInt("count");
                Log.d(TAG, "COUNT(id)值为: " + count);
            } catch (JSONException e) {
                Log.e(TAG, "Error: " + e.getMessage());
            }
        }
    }
}