一：从微信素材库获取照片

1.获取的url

get请求

https://qyapi.weixin.qq.com/cgi-bin/media/get

2.需要的参数

@Data
@ApiModel(value = "CompanyWeChatUploadImgDto", description = "企业微信图片上传实体类")
public class CompanyWeChatUploadImgDto implements Serializable {
    private static final long serialVersionUID = 6708935565631318783L;
    @ApiModelProperty("秘钥")
    @NotBlank(message = "秘钥不能为空")
    private String accessToken;
    @ApiModelProperty("图片位置id")
    @NotBlank(message = "图片位置id不能为空")
    private String mediaId;
}

accessToken和mediaId都是由前端人员传递，后台负责接收就行

3.使用restTemplate远程调用获取图片

        String url = weChatUrl+ "?access_token=" + accessToken + "&media_id=" + mediaId;
        ResponseEntity<byte[]> exchange = restTemplate.exchange(url, HttpMethod.GET, null, byte[].class);

我们将exchange的返回值定义为byte数组，方便后续转化

4.将byte数组转化为inputStream

byte[] data = exchange.getBody();
InputStream inputStream = new ByteArrayInputStream(data);

5.将inputStream写入图片要上传的路径

String imgUrl = "image/20221207135456/photo.jpg";
File newFile = new File(imgUrl );
FileUtils.copyInputStreamToFile(inputStream, newFile);

二：将流文件上传目标服务器

1.上传文件

//上传文件
boolean upload = uploadImg(newFile, imgUrl);

2.代码实现

    /**
     * 上传文件到服务器
     *
     * @param uploadFile 文件
     * @param imgUrl   文件路径
     * @return 是否上传
     */
    public boolean uploadImg(File uploadFile, String imgUrl) {
        if (!uploadFile.exists()) {
            return false;
        }
        try {
            // 创建ObsClient实例
            ObsClient obsClient = new ObsClient(ak, sk, endPoint);
            PutObjectResult putObjectResult = obsClient.putObject(bucketName, imgUrl, uploadFile);
            if (putObjectResult.getStatusCode() == HttpServletResponse.SC_OK) {
                return true;
            }
            return false;
        } catch (Exception e) {
            log.error("文件上传失败obs，文件名：{}", imgUrl);
            return false;
        } finally {
            //删除本地文件
            uploadFile.deleteOnExit();
        }
    }

三：从上传的服务器获取图片路径

public void dealImgUrl(HttpServletResponse response, String imgUrl) throws IOException {
        // 创建ObsClient实例
        ObsClient obsClient = new ObsClient(ak, sk, endPoint);
        ObsObject obsObject = obsClient.getObject(bucketName, imgUrl);
        OutputStream os = response.getOutputStream();
        InputStream is = obsObject.getObjectContent();
        // 只允许 jpeg，png 和 gif
        try {
            if (pictureKey.endsWith(".jpeg")) {
                response.setContentType("image/jpeg");
            }
            if (pictureKey.endsWith(".png")) {
                response.setContentType("image/png");
            }
            if (pictureKey.endsWith(".gif")) {
                response.setContentType("image/gif");
            }
            byte[] buf = new byte[1024];
            int len = 0;
            while ((len = is.read(buf)) > 0) {
                os.write(buf, 0, len);
            }
            os.flush();
        } catch (Exception e) {
            log.error("FileManagementUtils.downloadFile error = {}", e);
            throw e;
        } finally {
            is.close();
            os.close();
        }
    }