我如何使用Google的Gson从JSON响应中获得某个值？

Question

下面是我到目前为止的代码，我将Json放在一个字符串中：

import java.io.*;
import java.net.*;
import com.google.gson.*;

public class Subreddits {

public static void main(String[] args) {
    URL u = null;
    try {
        u = new URL("http://www.reddit.com/.json");
    } catch (MalformedURLException e) {
        e.printStackTrace();
    }
    URLConnection yc = null;
    try {
        yc = u.openConnection();
    } catch (IOException e) {
        e.printStackTrace();
    }
    BufferedReader in = null;
    try {
        in = new BufferedReader(new InputStreamReader(yc.getInputStream()));
    } catch (IOException e) {
        e.printStackTrace();
    }
    String inputLine = null;
    StringBuilder sb = new StringBuilder();
    try {
        while ((inputLine = in.readLine()) != null){
            sb.append(inputLine);
        }
    } catch (IOException e) {
        e.printStackTrace();
    }
    try {
        in.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
    inputLine = sb.toString();//String of json
    System.out.println(inputLine);
    //I want to get [data][children][data][subreddit]
}

}

Answer 1

您可以创建这个类结构来解析响应（用伪代码）：

class Response
  Data data

class Data
  List<Child> children

class Child
  OtherData data

class OtherData
  String subreddit

然后用以下语句解析JSON字符串：

Gson gson = new Gson();
Response response = gson.fromJson(inputLine, Response.class);

为了获得所需的具体数据，只需：

String subreddit = response.getData().getChildren().getOtherData().getSubreddit();