微信公众号上传媒体文件

本文主要是介绍微信公众号上传媒体文件，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

公众号在使用接口时，对多媒体文件、多媒体消息的获取和调用等操作，是通过media_id来进行的。通过本接口，公众号可以上传或下载多媒体文件。但请注意，每个多媒体文件（media_id）会在上传、用户发送到微信服务器3天后自动删除，以节省服务器资源。

公众号可调用本接口来上传图片、语音、视频等文件到微信服务器，上传后服务器会返回对应的media_id，公众号此后可根据该media_id来获取多媒体。请注意，media_id是可复用的，调用该接口需http协议。

接口调用请求说明

http请求方式: POST/FORM
http://file.api.weixin.qq.com/cgi-bin/media/upload?access_token=ACCESS_TOKEN&type=TYPE
调用示例（使用curl命令，用FORM表单方式上传一个多媒体文件）：
curl -F media=@test.jpg "http://file.api.weixin.qq.com/cgi-bin/media/upload?access_token=ACCESS_TOKEN&type=TYPE"

首先封装一个HttpPostUtil类，专门负责文件上传请求及一些参数的设置(此处可以理解为上传文件表单参数设置和connection的一些必须设置)、字符编码，文件类型等。

HttpPostUtil类代码：

import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Set;/*** * @author Sunlight* */
public class HttpPostUtil {private URL url;private HttpURLConnection conn;private String boundary = "--------httppost123";private HashMap<String, String> textParams = new HashMap<String, String>();private HashMap<String, File> fileparams = new HashMap<String, File>();private DataOutputStream outputStream;public HttpPostUtil(String url) throws Exception {this.url = new URL(url);}/*** 重新设置要请求的服务器地址，即上传文件的地址。* * @param url* @throws Exception*/public void setUrl(String url) throws Exception {this.url = new URL(url);}/*** 增加一个普通字符串数据到form表单数据中* * @param name* @param value*/public void addParameter(String name, String value) {textParams.put(name, value);}/*** 增加一个文件到form表单数据中* * @param name* @param value*/public void addParameter(String name, File value) {fileparams.put(name, value);}/*** 清空所有已添加的form表单数据*/public void clearAllParameters() {textParams.clear();fileparams.clear();}/*** 发送数据到服务器，返回一个字节包含服务器的返回结果的数组* * @return* @throws Exception*/public String send() throws Exception {initConnection();conn.connect();outputStream = new DataOutputStream(conn.getOutputStream());writeFileParams();writeStringParams();paramsEnd();int code = conn.getResponseCode();if (code == 200) {InputStream in = conn.getInputStream();ByteArrayOutputStream out = new ByteArrayOutputStream();byte[] buf = new byte[1024 * 8];int len;while ((len = in.read(buf)) != -1) {out.write(buf, 0, len);}conn.disconnect();String s = new String(out.toByteArray(), "utf-8");return s;}return null;}/*** 文件上传的connection的一些必须设置* * @throws Exception*/private void initConnection() throws Exception {conn = (HttpURLConnection) this.url.openConnection();conn.setDoOutput(true);conn.setUseCaches(false);conn.setConnectTimeout(10000); // 连接超时为10秒conn.setRequestMethod("POST");conn.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + boundary);}/*** 普通字符串数据* * @throws Exception*/private void writeStringParams() throws Exception {Set<String> keySet = textParams.keySet();for (Iterator<String> it = keySet.iterator(); it.hasNext();) {String name = it.next();String value = textParams.get(name);outputStream.writeBytes("--" + boundary + "\r\n");outputStream.writeBytes("Content-Disposition: form-data; name=\"" + name + "\"\r\n");outputStream.writeBytes("\r\n");outputStream.writeBytes(encode(value) + "\r\n");}}/*** 文件数据* * @throws Exception*/private void writeFileParams() throws Exception {Set<String> keySet = fileparams.keySet();for (Iterator<String> it = keySet.iterator(); it.hasNext();) {String name = it.next();File value = fileparams.get(name);outputStream.writeBytes("--" + boundary + "\r\n");outputStream.writeBytes("Content-Disposition: form-data; name=\"" + name + "\"; filename=\"" + encode(value.getName()) + "\"\r\n");outputStream.writeBytes("Content-Type: " + getContentType(value) + "\r\n");outputStream.writeBytes("\r\n");outputStream.write(getBytes(value));outputStream.writeBytes("\r\n");}}/*** 获取文件的上传类型，图片格式为image/png,image/jpeg等。非图片为application /octet-stream* * @param f* @return* @throws Exception*/private String getContentType(File f) throws Exception {return "application/octet-stream";}/*** 把文件转换成字节数组* * @param f* @return* @throws Exception*/private byte[] getBytes(File f) throws Exception {FileInputStream in = new FileInputStream(f);ByteArrayOutputStream out = new ByteArrayOutputStream();byte[] b = new byte[1024];int n;while ((n = in.read(b)) != -1) {out.write(b, 0, n);}in.close();return out.toByteArray();}/*** 添加结尾数据* * @throws Exception*/private void paramsEnd() throws Exception {outputStream.writeBytes("--" + boundary + "--" + "\r\n");outputStream.writeBytes("\r\n");}/*** 对包含中文的字符串进行转码，此为UTF-8。服务器那边要进行一次解码* * @param value* @return* @throws Exception*/private String encode(String value) throws Exception {return URLEncoder.encode(value, "UTF-8");}	
}

上传测试方法（可以在自己项目中上传文件到一些第三方提供的平台）：

/*** 使用方法示例* 此方法需要修改成自己上传地址才可上传成功* @param args* @throws Exception*/
public static void test(String[] args) throws Exception {File file=new File("D\\up.jpg");//此处修改为自己上传文件的地址HttpPostUtil post = new HttpPostUtil("http://www.omsdn.cn"); //此处参数类似 curl -F media=@test.jpgpost.addParameter("media", file);post.send();
}

上传文件方法封装好后，微信公众号上传文件类调用,此处需要JSON包（json-lib-2.2.3-jdk13.jar）：

import java.io.File;
import cn.<span style="font-family:FangSong_GB2312;">xx</span>.wechat.model.MdlUpload;
import cn.<span style="font-family:FangSong_GB2312;">xx</span>.wechat.model.Result;
import net.sf.json.JSONObject;
/*** * @author Sunlight**/
public class FileUpload {private static final String upload_url = "https://qyapi.weixin.qq.com/cgi-bin/media/upload?access_token=ACCESS_TOKEN&type=TYPE";
/**
* 上传文件
* 
* @param accessToken
* @param type
* @param file
* @return
*/
public static Result<MdlUpload> Upload(String accessToken, String type, File file) {
Result<MdlUpload> result = new Result<MdlUpload>();
String url = upload_url.replace("ACCESS_TOKEN", accessToken).replace("TYPE", type);
JSONObject jsonObject;
try {
HttpPostUtil post = new HttpPostUtil(url);
post.addParameter("media", file);
String s = post.send();
jsonObject = JSONObject.fromObject(s);
if (jsonObject.containsKey("media_id")) {
MdlUpload upload=new MdlUpload();
upload.setMedia_id(jsonObject.getString("media_id"));
upload.setType(jsonObject.getString("type"));
upload.setCreated_at(jsonObject.getString("created_at"));
result.setObj(upload);
result.setErrmsg("success");
result.setErrcode("0");
} else {
result.setErrmsg(jsonObject.getString("errmsg"));
result.setErrcode(jsonObject.getString("errcode"));
}
} catch (Exception e) {
e.printStackTrace();
result.setErrmsg("Upload Exception:"+e.toString());
}
return result;
}
}

调用方法需要引用2个Model类（返回结果类和上传文件类型类）：

返回结果类：

package cn.<span style="font-family:FangSong_GB2312;">xx</span>.wechat.model;public class Result<T> {private T obj;private String errcode;private String errmsg;public T getObj() {return obj;}public void setObj(T obj) {this.obj = obj;}
<span style="font-family:FangSong_GB2312;">        </span>public String getErrcode() {return errcode;}public void setErrcode(String errcode) {this.errcode = errcode;}public String getErrmsg() {return errmsg;}public void setErrmsg(String errmsg) {this.errmsg = errmsg;}}

文件上传返回文件类型类：

package cn.<span style="font-family:FangSong_GB2312;">xx</span>.wechat.model;public class MdlUpload {private String type;private String media_id;private String created_at;public String getType() {return type;}public void setType(String type) {this.type = type;}public String getMedia_id() {return media_id;}public void setMedia_id(String mediaId) {media_id = mediaId;}public String getCreated_at() {return created_at;}public void setCreated_at(String createdAt) {created_at = createdAt;}public MdlUpload() {super();}@Overridepublic String toString() {return "MdlUpload [created_at=" + created_at + ", media_id=" + media_id + ", type=" + type + "]";}}

最后微信上传文件测试方法：

@Test
public void testUpload() {
File file=new File("E:\\Tulips.jpg");
System.err.println(file.getName());
Result<MdlUpload> result=FileUpload .Upload("image", file);
System.out.println("Errcode="+result.getErrcode()+"\tErrmsg="+result.getErrmsg());
System.out.println(result.getObj().toString());
}

测试结果：

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