java - REST 和 JSON - 将字符串转换为 JSON 数组

Question

我是 JSON 和 REST 的新手。我正在使用一个返回如下字符串的服务器:

[{"username":"Hello","email":"hello@email.com","credits":"100","twitter_username":""},{"username":"Goodbye","email":"goodbye@email.com","credits":"0","twitter_username":""}]

我已经设法在控制台上将它们打印为字符串，但现在我想将它们转换为 JSON 数组。到目前为止，我的代码没有返回任何错误，但我不知道将什么放入新 JSON 数组的构造函数中。我一直在引用一位同事发给我的一段代码，其中的构造函数是 new JSONArray(response)，但他从未告诉我“response”是什么。

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

import net.sf.json.JSONArray;
import net.sf.json.JSONObject;

import sun.misc.BASE64Encoder;

public class NetClientGet {

    public static void main(String[] args) {

      try {

        URL url = new URL("http://username:password@mobile.crowdedmedia.co.uk/index.php/api/users/get_users/");
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setRequestMethod("GET");

        BASE64Encoder enc = new sun.misc.BASE64Encoder();
        String userpassword = "username:password";
        String encoded = enc.encode(userpassword.getBytes());
        conn.setRequestProperty("Authorization", "Basic " + encoded);

        if (conn.getResponseCode() != 200) {
            throw new RuntimeException("Failed : HTTP error code : "
                    + conn.getResponseCode());
        }

        BufferedReader br = new BufferedReader(new InputStreamReader(
            (conn.getInputStream())));

        String output;
        System.out.println("Output from Server .... \n");
        while ((output = br.readLine()) != null) {
            System.out.println(output);
        }

        JSONArray array = new JSONArray(output);

        for (int i =0; i < array.size(); i++) {
            JSONObject row = array.getJSONObject(i);
            String user = row.getString("username");
            System.out.println(user);
        }

        conn.disconnect();

      } catch (MalformedURLException e) {

        e.printStackTrace();

      } catch (IOException e) {

        e.printStackTrace();

      }

    }
}

Answer 1

• 使用GSON将字符串格式化为 JsonArray
• 然后遍历JsonArray获取值

代码示例

String json = "[{\"username\":\"Hello\",\"email\":\"hello@email.com\",\"credits\":\"100\",\"twitter_username\":\"\"},{\"username\":\"Goodbye\",\"email\":\"goodbye@email.com\",\"credits\":\"0\",\"twitter_username\":\"\"}]";
JsonArray jArray = new JsonParser().parse(json).getAsJsonArray();
for (int i=0;i<jArray.size();i++) {
    JsonObject jsonObject = jArray.get(i).getAsJsonObject();
    System.out.println(jsonObject.get("username"));
    System.out.println(jsonObject.get("email"));
    System.out.println(jsonObject.get("credits"));
    System.out.println(jsonObject.get("twitter_username"));
    System.out.println("*********");
}