网页爬虫 - java如何模拟浏览器请求获取json文件

Question

最近在想怎么不用jsonp来完成跨域的json获取并解析，大概的思路就是服务器端获取json，解析，客户端，只需要在本都调我的这个接口就行了，但是本人能力有限，怎么来模拟浏览器获取json文件呢

Answer 1

I found a piece of code on the Internet and modified it. It should be able to meet your requirements (I used fastjson, I have never used it before, so I searched it now)

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.URL;
import java.net.URLConnection;
import java.util.List;
import java.util.Map;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;

public class getJson {
    public static void main(String[] args) {
        //查询Ip信息的接口，返回json
        String url="https://sp0.baidu.com/8aQDcjqpAAV3otqbppnN2DJv/api.php?query=2.24.1.1&resource_id=6006&format=json";
        String result = "";
        BufferedReader in = null;
        try {
            String urlNameString = url;
            URL realUrl = new URL(urlNameString);
            // 打开和URL之间的连接
            URLConnection connection = realUrl.openConnection();
            // 建立实际的连接
            connection.connect();
            // 获取所有响应头字段
            Map<String, List<String>> map = connection.getHeaderFields();
            // 定义 BufferedReader输入流来读取URL的响应
            in = new BufferedReader(new InputStreamReader(
                    connection.getInputStream()));
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            System.out.println("发送GET请求出现异常！" + e);
            e.printStackTrace();
        }
        // 使用finally块来关闭输入流
        finally {
            try {
                if (in != null) {
                    in.close();
                }
            } catch (Exception e2) {
                e2.printStackTrace();
            }
        }
        //得到的json数据
        System.out.println(result);
        //解析,
        JSONObject jsonObj = JSON.parseObject(result); 
        JSONArray jarr =  jsonObj.getJSONArray("data");
        JSONObject j0 = (JSONObject)jarr.get(0);
        //输出该ip对应的地理位置
        System.out.println(j0.get("location"));
    }

}

The process is probably like this. I personally think it is troublesome to parse json with a strongly typed language like java. If you don’t have to use java, it would be more appropriate to use python to do this