Java公众号开发系列（二）：新增和获取临时素材

{"type":"TYPE","media_id":"MEDIA_ID","created_at":123456789}

{"errcode":40004,"errmsg":"invalid media type"}

{
 "video_url":DOWN_URL
}

{
  "errcode":40007,
  "errmsg":"invalid media_id"
}

<!-- 上传临时素材方式使用okhttp框架-->
<dependency>
    <groupId>com.squareup.okhttp3</groupId>
    <artifactId>okhttp</artifactId>
    <version>4.9.1</version>
</dependency>

import cn.hutool.core.util.StrUtil;
import cn.hutool.http.HttpUtil;
import cn.hutool.json.JSONObject;
import cn.hutool.json.JSONUtil;
import java.io.*;
import java.net.URL;
import java.util.Objects;
import okhttp3.*;
/**
 * 临时素材上传、下载
 */
public class Demo2_AddTemporaryMedia {
    public static void main(String[] args) throws IOException {
        String imgurl = "https://developer.qcloudimg.com/user/attachment/4392601/20231019-977f3b10.png";
        // 获取公众号token
        String token = "";
        //上传图片素材
        String mediaId= uploadTemporaryMedia(imgurl, token);
        // 下载图片素材到本地
        GetTemporaryMediaByMediaId(mediaId,token);
    }
    /**
     * 上传临时素材获取 media_id
     *
     * @param imageUrl
     * @param accessToken
     * @return
     * @throws IOException
     */
    private static String uploadTemporaryMedia(String imageUrl, String accessToken) throws IOException {
        URL url = new URL(imageUrl);
        InputStream inputStream = url.openStream();
        OkHttpClient client = new OkHttpClient();
        RequestBody requestBody = new MultipartBody.Builder()
                .setType(MultipartBody.FORM)
                .addFormDataPart("media", "image.png",
                        RequestBody.create(MediaType.parse("image/png"), Objects.requireNonNull(inputStreamToBytes(inputStream))))
                .build();
        Request request = new Request.Builder()
                .url("https://api.weixin.qq.com/cgi-bin/media/upload?access_token=" + accessToken + "&type=image")
                .post(requestBody)
                .build();
        Response response = client.newCall(request).execute();
        String responseBody = "";
        if (response.isSuccessful()) {
            responseBody = Objects.requireNonNull(response.body()).string();
            System.out.println(responseBody);
        } else {
            System.out.println("Request failed: " + response.code() + " - " + response.message());
        }
        response.close();
        // 解析返回结果，获取上传后的媒体 ID
        JSONObject result = JSONUtil.parseObj(responseBody);
        System.out.println(result.get("media_id").toString());
        return result.get("media_id").toString();
    }

    /**
     * 下载微信素材到本地
     * @param mediaId 媒体id
     * @param accessToken 公众号token
     * @throws FileNotFoundException
     */
    private static void GetTemporaryMediaByMediaId(String mediaId, String accessToken) throws FileNotFoundException {
        String url = StrUtil.format("https://api.weixin.qq.com/cgi-bin/media/get?access_token={}&media_id={}", accessToken, mediaId);
        HttpUtil.downloadFile(url,"D:\\test.png");
    }
    /**
     * 转为为byte数组
     *
     * @param inputStream
     * @return
     * @throws IOException
     */
    private static byte[] inputStreamToBytes(InputStream inputStream) throws IOException {
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        byte[] buffer = new byte[4096];
        int bytesRead;
        while ((bytesRead = inputStream.read(buffer)) != -1) {
            byteArrayOutputStream.write(buffer, 0, bytesRead);
        }
        byteArrayOutputStream.close();
        return byteArrayOutputStream.toByteArray();
    }
}