Java-微信开发上传永久素材(支持所有文件类型)

/**
	 * 上传永久素材
	 * @param	file
	 * @param	type
	 * @param	title type为video时需要,其他类型设null
	 * @param	introduction type为video时需要,其他类型设null
	 * @return	{"media_id":MEDIA_ID,"url":URL}
	 */
	public static String uploadPermanentMaterial(File file, String type, String title, String introduction) {
		
		String access_token = "10__IK_6jLYuvdvIwdftOObUbTt8HcKZER8UBjvxD6CVpbJRBYGtGQ-HmqfnSrg4YBxQ4wBS4DPaksWeQzte1jmh1g1zLULAOA4leL5iekLX5tdQYlqRQJtSKOh6FeratK4WBlNT0cXdDXPdplKFQHfAIAOZQ";
		String url = "https://api.weixin.qq.com/cgi-bin/material/add_material?access_token="
				+ access_token + "&type=" + type;
 
		String result = null;
 
		try {
			URL uploadURL = new URL(url);
 
			HttpURLConnection conn = (HttpURLConnection) uploadURL.openConnection();
			conn.setConnectTimeout(5000);
			conn.setReadTimeout(30000);
			conn.setDoOutput(true);
			conn.setDoInput(true);
			conn.setUseCaches(false);
			conn.setRequestMethod("POST");
			conn.setRequestProperty("Connection", "Keep-Alive");
			conn.setRequestProperty("Cache-Control", "no-cache");
			String boundary = "-----------------------------" + System.currentTimeMillis();
			conn.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + boundary);
 
			OutputStream output = conn.getOutputStream();
			output.write(("--" + boundary + "
").getBytes());
			output.write(String.format("Content-Disposition: form-data; name="media"; filename="%s"
", file.getName()).getBytes());
			output.write("Content-Type: video/mp4 

".getBytes());
 
			byte[] data = new byte[1024];
			int len = 0;
			FileInputStream input = new FileInputStream(file);
			while ((len = input.read(data)) > -1) {
				output.write(data, 0, len);
			}
 
			/*对类型为video的素材进行特殊处理*/
			if ("video".equals(type)) {
				output.write(("--" + boundary + "
").getBytes());
				output.write("Content-Disposition: form-data; name="description";

".getBytes());
				output.write(String.format("{"title":"%s", "introduction":"%s"}", title, introduction).getBytes());
			}
 
			output.write(("
--" + boundary + "--

").getBytes());
			output.flush();
			output.close();
			input.close();
			
			InputStream resp = conn.getInputStream();
 
			StringBuffer sb = new StringBuffer();
 
			while ((len = resp.read(data)) > -1)
				sb.append(new String(data, 0, len, "utf-8"));
			resp.close();
			result = sb.toString();
		} catch (IOException e) {
			//....
		}
		
		return result;
	}