读取并解析json文件 http123

最新推荐文章于 2020-04-20 21:01:28 发布

转载最新推荐文章于 2020-04-20 21:01:28 发布 · 1.5k 阅读

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原文链接：https://my.oschina.net/AnniHome/blog/3185402

文章标签：

#json

本文介绍了一种使用Java从在线JSON文件中读取数据的方法，并详细展示了如何解析JSON内容，下载其中包含的图片到本地，同时打印出图片的文件名和大小。

读取并解析json文件: http://123.56.191.196:8080/a/a/d/list_slide_1_0.json，必须是在线读取。把里面的图片下载到本地，并打印出图片文件名和文件大小。

package com.java;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
import okhttp3.ConnectionPool;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.concurrent.TimeUnit;
public class jsonDemo {

    private static final OkHttpClient client = new OkHttpClient.Builder()
            .connectTimeout(10, TimeUnit.SECONDS)
            .writeTimeout(15, TimeUnit.SECONDS)
            .readTimeout(15, TimeUnit.SECONDS)
            .connectionPool(new ConnectionPool(10, 60, TimeUnit.SECONDS))
            .retryOnConnectionFailure(true)
            .build();
            public static void main(String[] args) {

        Request request = new Request.Builder()
                .url("http://123.56.191.196:8080/a/a/d/list_slide_1_0.json")
                .get()
                .build();
        //请求URL下载内容
        try (Response response = client.newCall(request).execute()) {
            if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);
            String responseText = response.body().string();
            //转为json数组
            JSONArray objects = JSON.parseArray(responseText);
            for (int i = 0; i < objects.size(); i++) {
                JSONObject jsonObject = objects.getJSONObject(i);
                String photoUrl = jsonObject.getString("photo");
                String title = jsonObject.getString("title");
                //下载图片
                downloadPicture(photoUrl, title);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    private static void downloadPicture(String url, String title) {
        Request request = new Request.Builder()
                .url(url)
                .get()
                .build();
        try (Response response = client.newCall(request).execute()) {
            if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);
            InputStream inputStream = response.body().byteStream();
            String fileName = "D:\\data" + title + ".jpg";
            FileOutputStream outputStream = new FileOutputStream(fileName);
            byte[] data = new byte[1024];
            int i, fileSize = 0;
            while ((i = inputStream.read(data, 0, data.length)) > 0) {
                outputStream.write(data, 0, i);
                fileSize += i;
            }
            System.out.println("文件名：" + fileName);
            System.out.println("文件大小：" + fileSize + "B");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

}