公众号上传临时素材获取media_id

java语言
更新于2018-01-15

public class Util{
    private static final String UPLOAD_URL = "https://api.weixin.qq.com/cgi-bin/media/upload?access_token=ACCESS_TOKEN&type=TYPE";
    public static String uploadFile(String filePath, String accessToken, String type) throws Exception{
        File file = new File(filePath);
        if(!file.exists() || !file.isFile()) {
            throw new IOException("文件不存在！");
        }

        String url = UPLOAD_URL.replace("ACCESS_TOKEN", accessToken).replace("TYPE", type);
        URL urlObj = new URL(url);

        //连接
        HttpURLConnection conn = (HttpURLConnection) urlObj.openConnection();

        conn.setRequestMethod("POST");
        conn.setDoInput(true);
        conn.setDoOutput(true);
        conn.setUseCaches(false);

        //请求头
        conn.setRequestProperty("Connection", "Keep-Alive");
        conn.setRequestProperty("Charset", "UTF-8");
        //conn.setRequestProperty("Content-Type","multipart/form-data;");

        //设置边界
        String BOUNDARY = "----------" + System.currentTimeMillis();
        conn.setRequestProperty("Content-Type","multipart/form-data;boundary="+BOUNDARY);

        StringBuilder sb = new StringBuilder();
        sb.append("--");
        sb.append(BOUNDARY);
        sb.append("\r\n");
        sb.append("Content-Disposition:form-data;name=\"file\";filename=\""+file.getName()+"\"\r\n");
        sb.append("Content-Type:application/octet-stream\r\n\r\n");

        byte[] head = sb.toString().getBytes("utf-8");

        //输出流
        OutputStream out = new DataOutputStream(conn.getOutputStream());

        out.write(head);

        //文件正文部分
        DataInputStream in = new DataInputStream(new FileInputStream(file));
        int bytes = 0;
        byte[] bufferOut = new byte[1024];
        while((bytes = in.read(bufferOut))!=-1) {
            out.write(bufferOut,0,bytes);
        }
        in.close();

        //结尾
        byte[] foot = ("\r\n--" + BOUNDARY + "--\r\n").getBytes("utf-8");
        out.write(foot);
        out.flush();
        out.close();

        //获取响应
        StringBuffer buffer = new StringBuffer();
        BufferedReader reader = null;
        String result = null;

        reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
        String line = null;
        while((line = reader.readLine()) != null) {
            buffer.append(line);
        }
        if(result == null) {
            result = buffer.toString();
        }
        reader.close();

        //需要添加json-lib  jar包
        JSONObject json = JSONObject.fromObject(result);
        System.out.println(json);
        String mediaId = json.getString("media_id");

        return mediaId;
    }
}