java 实现微信服务器下载图片到自己服务器

 java 实现微信服务器下载图片到自己服务器

此功能的实现需要注意java 中IO流的操作及网路开发，

实现代码：

/**
 * @author why
 *
 */
public class PicDownload { 

  /**
   *
   * 根据文件id下载文件
   *
   *
   *
   * @param mediaId
   *
   *      媒体id
   *
   * @throws Exception
   */ 

  public static InputStream getInputStream(String accessToken, String mediaId) {
    InputStream is = null;
    String url = "http://file.api.weixin.qq.com/cgi-bin/media/get?access_token="
        + accessToken + "&media_id=" + mediaId;
    try {
      URL urlGet = new URL(url);
      HttpURLConnection http = (HttpURLConnection) urlGet
          .openConnection();
      http.setRequestMethod("GET"); // 必须是get方式请求
      http.setRequestProperty("Content-Type",
          "application/x-www-form-urlencoded");
      http.setDoOutput(true);
      http.setDoInput(true);
      System.setProperty("sun.net.client.defaultConnectTimeout", "30000");// 连接超时30秒
      System.setProperty("sun.net.client.defaultReadTimeout", "30000"); // 读取超时30秒
      http.connect();
      // 获取文件转化为byte流
      is = http.getInputStream(); 

    } catch (Exception e) {
      e.printStackTrace();
    }
    return is; 

  } 

  /**
   *
   * 获取下载图片信息（jpg）
   *
   *
   *
   * @param mediaId
   *
   *      文件的id
   *
   * @throws Exception
   */ 

  public static void saveImageToDisk(String accessToken, String mediaId, String picName, String picPath)
      throws Exception {
    InputStream inputStream = getInputStream(accessToken, mediaId);
    byte[] data = new byte[10240];
    int len = 0;
    FileOutputStream fileOutputStream = null;
    try {
      fileOutputStream = new FileOutputStream(picPath+picName+".jpg");
      while ((len = inputStream.read(data)) != -1) {
        fileOutputStream.write(data, 0, len);
      }
    } catch (IOException e) {
      e.printStackTrace();
    } finally {
      if (inputStream != null) {
        try {
          inputStream.close();
        } catch (IOException e) {
          e.printStackTrace();
        }
      }
      if (fileOutputStream != null) {
        try {
          fileOutputStream.close();
        } catch (IOException e) {
          e.printStackTrace();
        }
      }
    }
  } 

  /**
   * 图片下载
   *
   * @param accessToken
   * @param mediaId
   */
  public static void getPic(String accessToken, String mediaId) {
    String requestUrl = "http://file.api.weixin.qq.com/cgi-bin/media/get?access_token=ACCESS_TOKEN&media_id=MEDIA_ID";
    requestUrl = requestUrl.replace("ACCESS_TOKEN", accessToken).replace(
        "MEDIA_ID", mediaId);
    JSONObject jsonObject = WeixinUtil.httpRequest(requestUrl, "GET", null);
    System.out.println(jsonObject);
  } 

  public static void main(String[] args) throws Exception {
    String accessToken = "";
    String mediaId = "";
    String picName = "";
    saveImageToDisk(accessToken, mediaId, picName,"f:/");
  }
} 

感谢阅读，希望能帮助到大家，谢谢大家对本站的支持！