微信公众订阅号 上传临时素材示例

 1         try {
 2
 3             //声明分割线
 4             String boundary="-----";
 5
 6             //准备前期
 7             File file=new File(filePath);
 8             URL url=new URL("https://api.weixin.qq.com/cgi-bin/media/upload?access_token=Z_dtsiJWpgghBANNad1B9DS4sgfE9zOLmwIffYmDXDKs4ZWr6wmhX6xYNanplgB8BVsER8JFtRAnJlyc24kDiSfQwMIzIISbWKLHCkQU9ZhXYNokaZchKmA4QOtH6VoBTSBjAAAEDM&type=image");
 9             URLConnection urlConnection=url.openConnection();
10             urlConnection.setDoInput(true);
11             urlConnection.setDoOutput(true);
12             urlConnection.setUseCaches(false);
13             urlConnection.setRequestProperty("Connection","Keep-Alive");
14             urlConnection.setRequestProperty("Content-Type","multipart/form-data;boundary="+boundary);
15             urlConnection.setRequestProperty("Content-Length",String.valueOf(file.length()));
16
17             //获取文件输入流
18             InputStream inputStream=new FileInputStream(file);
19             //获取响应输出流
20             OutputStream outputStream = urlConnection.getOutputStream();
21
22             //准备写入头信息
23             outputStream.write((boundary+"--\r\n").getBytes());
24             outputStream.write(("Content-Disposition:form-data;name=\"media\";filename=\""+file.getName()+"\"\r\n").getBytes());
25             outputStream.write(("Content-Type:image/jpeg\r\n\r\n").getBytes());
26             //准备循环写入 文件流
27             byte[] b=new byte[1024];
28             int l;
29             while((l=inputStream.read(b,0,b.length))!=-1){
30                 outputStream.write(b,0,l);
31             }
32             outputStream.write(("\r\n"+boundary+"--\r\n").getBytes());
33
34             //关闭
35             outputStream.flush();
36             outputStream.close();
37             inputStream.close();
38
39             urlConnection.connect();
40
41             InputStream is=urlConnection.getInputStream();
42             int c;
43             while((c=is.read())!=-1){
44                 System.out.print((char)c);
45             }
46             is.close();
47         } catch (MalformedURLException e) {
48             e.printStackTrace();
49         } catch (IOException e) {
50             e.printStackTrace();
51         }

特别注意写入文件数据的时候，首尾都需要有分割线，并且分割线比RequestProperty里的Content-Type里的分割线多--个，并且注意换行

其次就是上传的name的值为media字符串

再其次注意请求所附带的参数