回复图片、音频、视频消息都是需要media_id的，这个是需要将多媒体文件上传到微信服务器才有的。
将多媒体文件上传到微信服务器，以及从微信服务器下载文件，可以参考：http://mp.weixin.qq.com/wiki/index.php?title=上传下载多媒体文件
上传下载多媒体文件的方法还是写到WeixinUtil.java中。
代码如下：
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.security.KeyManagementException;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.SecureRandom;
import java.util.Calendar;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import javax.net.ssl.HttpsURLConnection;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSocketFactory;
import javax.net.ssl.TrustManager;
import net.sf.json.JSONObject;
import org.apache.commons.lang.StringUtils;
import org.apache.log4j.Logger;
import com.company.project.model.menu.AccessToken;
import com.company.project.model.menu.Menu;
public class WeixinUtil {
private static Logger log = Logger.getLogger(WeixinUtil.class);
public final static String APPID = "wxb927d4280e6db674";
public final static String APP_SECRET = "21441e9f3226eee81e14380a768b6d1e";
// 获取access_token的接口地址（GET） 限200（次/天）
public final static String access_token_url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=APPID&secret=APPSECRET";
// 创建菜单
public final static String create_menu_url = "https://api.weixin.qq.com/cgi-bin/menu/create?access_token=ACCESS_TOKEN";
// 存放：1.token，2：获取token的时间,3.过期时间
public final static Map<String,Object> accessTokenMap = new HashMap<String,Object>();
/**
* 发起https请求并获取结果
*
* @param requestUrl 请求地址
* @param requestMethod 请求方式（GET、POST）
* @param outputStr 提交的数据
* @return JSONObject(通过JSONObject.get(key)的方式获取json对象的属性值)
*/
public static JSONObject handleRequest(String requestUrl,String requestMethod,String outputStr) {
JSONObject jsonObject = null;
try {
URL url = new URL(requestUrl);
HttpsURLConnection conn = (HttpsURLConnection) url.openConnection();
SSLContext ctx = SSLContext.getInstance("SSL", "SunJSSE");
TrustManager[] tm = {new MyX509TrustManager()};
ctx.init(null, tm, new SecureRandom());
SSLSocketFactory sf = ctx.getSocketFactory();
conn.setSSLSocketFactory(sf);
conn.setDoInput(true);
conn.setDoOutput(true);
conn.setRequestMethod(requestMethod);
conn.setUseCaches(false);
if ("GET".equalsIgnoreCase(requestMethod)) {
conn.connect();
}
if (StringUtils.isNotEmpty(outputStr)) {
OutputStream out = conn.getOutputStream();
out.write(outputStr.getBytes("utf-8"));
out.close();
}
InputStream in = conn.getInputStream();
BufferedReader br = new BufferedReader(new InputStreamReader(in,"utf-8"));
StringBuffer buffer = new StringBuffer();
String line = null;
while ((line = br.readLine()) != null) {
buffer.append(line);
}
in.close();
conn.disconnect();
jsonObject = JSONObject.fromObject(buffer.toString());
} catch (MalformedURLException e) {
e.printStackTrace();
log.error("URL错误！");
} catch (IOException e) {
e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (NoSuchProviderException e) {
e.printStackTrace();
} catch (KeyManagementException e) {
e.printStackTrace();
}
return jsonObject;
}
/**
* 获取access_token
*
* @author qincd
* @date Nov 6, 2014 9:56:43 AM
*/
public static AccessToken getAccessToken(String appid,String appSecret) {
AccessToken at = new AccessToken();
// 每次获取access_token时，先从accessTokenMap获取，如果过期了就重新从微信获取
// 没有过期直接返回
// 从微信获取的token的有效期为2个小时
if (!accessTokenMap.isEmpty()) {
Date getTokenTime = (Date) accessTokenMap.get("getTokenTime");
Calendar c = Calendar.getInstance();
c.setTime(getTokenTime);
c.add(Calendar.HOUR_OF_DAY, 2);
getTokenTime = c.getTime();
if (getTokenTime.after(new Date())) {
log.info("缓存中发现token未过期，直接从缓存中获取access_token");
// token未过期，直接从缓存获取返回
String token = (String) accessTokenMap.get("token");
Integer expire = (Integer) accessTokenMap.get("expire");
at.setToken(token);
at.setExpiresIn(expire);
return at;
}
}
String requestUrl = access_token_url.replace("APPID", appid).replace("APPSECRET", appSecret);
JSONObject object = handleRequest(requestUrl, "GET", null);
String access_token = object.getString("access_token");
int expires_in = object.getInt("expires_in");
log.info("\naccess_token:" + access_token);
log.info("\nexpires_in:" + expires_in);
at.setToken(access_token);
at.setExpiresIn(expires_in);
// 每次获取access_token后，存入accessTokenMap
// 下次获取时，如果没有过期直接从accessTokenMap取。
accessTokenMap.put("getTokenTime", new Date());
accessTokenMap.put("token", access_token);
accessTokenMap.put("expire", expires_in);
return at;
}
/**
* 创建菜单
*
* @author qincd
* @date Nov 6, 2014 9:56:36 AM
*/
public static boolean createMenu(Menu menu,String accessToken) {
String requestUrl = create_menu_url.replace("ACCESS_TOKEN", accessToken);
String menuJsonString = JSONObject.fromObject(menu).toString();
JSONObject jsonObject = handleRequest(requestUrl, "POST", menuJsonString);
String errorCode = jsonObject.getString("errcode");
if (!"0".equals(errorCode)) {
log.error(String.format("菜单创建失败！errorCode:%d,errorMsg:%s",jsonObject.getInt("errcode"),jsonObject.getString("errmsg")));
return false;
}
log.info("菜单创建成功！");
return true;
}
// 上传多媒体文件到微信服务器
public static final String upload_media_url = "http://file.api.weixin.qq.com/cgi-bin/media/upload?access_token=ACCESS_TOKEN&type=TYPE";
/**
* 上传多媒体文件到微信服务器<br>
* @see http://www.oschina.net/code/snippet_1029535_23824
* @see http://mp.weixin.qq.com/wiki/index.php?title=上传下载多媒体文件
*
* @author qincd
* @date Nov 6, 2014 4:11:22 PM
*/
public static JSONObject uploadMediaToWX(String filePath,String type,String accessToken) throws IOException{
File file = new File(filePath);
if (!file.exists()) {
log.error("文件不存在！");
return null;
}
String url = upload_media_url.replace("ACCESS_TOKEN", accessToken).replace("TYPE", type);
URL urlObj = new URL(url);
HttpURLConnection conn = (HttpURLConnection) urlObj.openConnection();
conn.setDoInput(true);
conn.setDoOutput(true);
conn.setUseCaches(false);
conn.setRequestProperty("Connection", "Keep-Alive");
conn.setRequestProperty("Charset", "UTF-8");
// 设置边界
String BOUNDARY = "----------" + System.currentTimeMillis();
conn.setRequestProperty("Content-Type", "multipart/form-data; boundary="
+ BOUNDARY);
// 请求正文信息
// 第一部分：
StringBuilder sb = new StringBuilder();
sb.append("--"); // ////////必须多两道线
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");
// 获得输出流
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();
// 结尾部分
byte[] foot = ("\r\n--" + BOUNDARY + "--\r\n").getBytes("utf-8");// 定义最后数据分隔线
out.write(foot);
out.flush();
out.close();
/**
* 读取服务器响应，必须读取,否则提交不成功
*/
try {
// 定义BufferedReader输入流来读取URL的响应
StringBuffer buffer = new StringBuffer();
BufferedReader reader = new BufferedReader(new InputStreamReader(
conn.getInputStream()));
String line = null;
while ((line = reader.readLine()) != null) {
buffer.append(line);
}
reader.close();
conn.disconnect();
return JSONObject.fromObject(buffer.toString());
} catch (Exception e) {
log.error("发送POST请求出现异常！" + e);
e.printStackTrace();
}
return null;
}
public static final String download_media_url = "http://file.api.weixin.qq.com/cgi-bin/media/get?access_token=ACCESS_TOKEN&media_id=MEDIA_ID";
/**
* 从微信服务器下载多媒体文件
*
* @author qincd
* @date Nov 6, 2014 4:32:12 PM
*/
public static String downloadMediaFromWx(String accessToken,String mediaId,String fileSavePath) throws IOException {
if (StringUtils.isEmpty(accessToken) || StringUtils.isEmpty(mediaId)) return null;
String requestUrl = download_media_url.replace("ACCESS_TOKEN", accessToken).replace("MEDIA_ID", mediaId);
URL url = new URL(requestUrl);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("GET");
conn.setDoInput(true);
conn.setDoOutput(true);
InputStream in = conn.getInputStream();
File dir = new File(fileSavePath);
if (!dir.exists()) {
dir.mkdirs();
}
if (!fileSavePath.endsWith("/")) {
fileSavePath += "/";
}
String ContentDisposition = conn.getHeaderField("Content-disposition");
String weixinServerFileName = ContentDisposition.substring(ContentDisposition.indexOf("filename")+10, ContentDisposition.length() -1);
fileSavePath += weixinServerFileName;
BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(fileSavePath));
byte[] data = new byte[1024];
int len = -1;
while ((len = in.read(data)) != -1) {
bos.write(data,0,len);
}
bos.close();
in.close();
conn.disconnect();
return fileSavePath;
}
}测试代码：
public class WeixinUtilTest {
/**
*
* @author qincd
* @date Nov 6, 2014 9:57:54 AM
*/
public static void main(String[] args) {
// 1).获取access_token
AccessToken accessToken = WeixinUtil.getAccessToken(WeixinUtil.APPID, WeixinUtil.APP_SECRET);
String filePath = "C:\\Users\\qince\\Pictures\\壁纸20141029091612.jpg";
JSONObject uploadJsonObj = testUploadMedia(filePath,"image",accessToken.getToken());
if (uploadJsonObj == null) {
System.out.println("上传图片失败");
return;
}
int errcode = 0;
if (uploadJsonObj.containsKey("errcode")) {
errcode = uploadJsonObj.getInt("errcode");
}
if (errcode == 0) {
System.out.println("图片上传成功");
String mediaId = uploadJsonObj.getString("media_id");
long createAt = uploadJsonObj.getLong("created_at");
System.out.println("--Details:");
System.out.println("media_id:" + mediaId);
System.out.println("created_at:" + createAt);
}
else {
System.out.println("图片上传失败！");
String errmsg = uploadJsonObj.getString("errmsg");
System.out.println("--Details:");
System.out.println("errcode:" + errcode);
System.out.println("errmsg:" + errmsg);
}
String mediaId = "6W-UvSrQ2hkdSdVQJJXShwtFDPLfbGI1qnbNFy8weZyb9Jac2xxxcAUwt8p4sYPH";
String filepath = testDownloadMedia(accessToken.getToken(), mediaId, "d:/test");
System.out.println(filepath);
}
/**
* 上传多媒体文件到微信
*
* @author qincd
* @date Nov 6, 2014 4:15:14 PM
*/
public static JSONObject testUploadMedia(String filePath,String type,String accessToken) {
try {
return WeixinUtil.uploadMediaToWX(filePath, type, accessToken);
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
/**
* 从微信下载多媒体文件
*
* @author qincd
* @date Nov 6, 2014 4:56:25 PM
*/
public static String testDownloadMedia(String accessToken,String mediaId,String fileSaveDir) {
try {
return WeixinUtil.downloadMediaFromWx(accessToken, mediaId, fileSaveDir);
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
}The above is the detailed content of Java WeChat development of uploading and downloading multimedia files. For more information, please follow other related articles on the PHP Chinese website!
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
