微信公众平台开发（2）-消息封装

今天药忘吃喽~ 2022-08-13 15:51 223阅读 0赞

微信公众平台开发（2）-消息处理  
消息包括文本、图片、语音、视频、音乐、图文，消息格式参考http://mp.weixin.qq.com/wiki/index.php?title=发送被动响应消息  
在接入接口时指定了回调URL，在保存时微信会以GET方式调用此URL，并将signature,timestamp,nonce,echostr添加到URL上  
因此在我们的微信处理的Controller中需要有执行上面URL的GET方法。  
  
  
那么，发送和接收消息怎么来实现呢？  
这个是通过以POST方式调用上述URL来实现的。  
用户发送的数据通过微信包装以后POST到上面的URL，微信包装的各个类型的消息结构如下：  
http://mp.weixin.qq.com/wiki/index.php?title=接收普通消息  
比如， 用户通过微信发送一段文本，那么我们可以从输入流中拿到微信服务器发送的数据。  
比如：  
<xml>  
 <ToUserName><!\[CDATA\[toUser\]\]></ToUserName>  
 <FromUserName><!\[CDATA\[fromUser\]\]></FromUserName>   
 <CreateTime>1348831860</CreateTime>  
 <MsgType><!\[CDATA\[text\]\]></MsgType>  
 <Content><!\[CDATA\[this is a test\]\]></Content>  
 <MsgId>1234567890123456</MsgId>  
 </xml>  
   
 这样，就可以知道用户发送的是什么内容了。  
 那么，如果响应用户呢？  
 http://mp.weixin.qq.com/wiki/index.php?title=发送被动响应消息  
 上面定义了响应各个类型消息的结构  
 组装响应结构的xml数据，并写到输出流，微信就会解析，并发送给用户了。  
 比如回复文本，如：  
 <xml>  
<ToUserName><!\[CDATA\[toUser\]\]></ToUserName>  
<FromUserName><!\[CDATA\[fromUser\]\]></FromUserName>  
<CreateTime>12345678</CreateTime>  
<MsgType><!\[CDATA\[text\]\]></MsgType>  
<Content><!\[CDATA\[你好\]\]></Content>  
</xml>  
ToUserName,FromUserName通过接受用户的消息就知道了，那么再组装一下其他内容就可以了。  
  
  
首先呢，通过解析输入流可以拿到XML的各个节点内容，然后放到Map中。  
这里使用dom4j来解析，代码参考后面的MessageUtil.parseXml()方法。  
  
  
响应时，我们按照文档中给的XML结构组装XML就可以了。  
当然，你用字符串来拼当然可以，但是这样很麻烦。我们可以通过xstream来实现Bean到Xml的转换。  
说到Bean呢，观察一下响应的各个类型的消息的XML结构，发现有一些属性是共有的。  
那么将这些共有的属性组装成一个基类BaseMessage，其他各个类型的消息继承BaseMessage，如下：  
import java.io.Serializable;  
  
  
public class BaseMessage implements Serializable \{  
  
  
private String ToUserName;  
private String FromUserName;  
private Long CreateTime;  
private String MsgType;  
private Long MsgId;  
/\*\*  
\* @return the toUserName  
\*/  
public String getToUserName() \{  
return ToUserName;  
\}  
/\*\*  
\* @param toUserName the toUserName to set  
\*/  
public void setToUserName(String toUserName) \{  
ToUserName = toUserName;  
\}  
/\*\*  
\* @return the fromUserName  
\*/  
public String getFromUserName() \{  
return FromUserName;  
\}  
/\*\*  
\* @param fromUserName the fromUserName to set  
\*/  
public void setFromUserName(String fromUserName) \{  
FromUserName = fromUserName;  
\}  
/\*\*  
\* @return the createTime  
\*/  
public Long getCreateTime() \{  
return CreateTime;  
\}  
/\*\*  
\* @param createTime the createTime to set  
\*/  
public void setCreateTime(Long createTime) \{  
CreateTime = createTime;  
\}  
/\*\*  
\* @return the msgType  
\*/  
public String getMsgType() \{  
return MsgType;  
\}  
/\*\*  
\* @param msgType the msgType to set  
\*/  
public void setMsgType(String msgType) \{  
MsgType = msgType;  
\}  
/\*\*  
\* @return the msgId  
\*/  
public Long getMsgId() \{  
return MsgId;  
\}  
/\*\*  
\* @param msgId the msgId to set  
\*/  
public void setMsgId(Long msgId) \{  
MsgId = msgId;  
\}  
  
  
\}  
  
  
然后是文本消息：  
public class TextMessage extends BaseMessage \{  
  
  
private String Content;  
  
  
/\*\*  
\* @return the content  
\*/  
public String getContent() \{  
return Content;  
\}  
  
  
/\*\*  
\* @param content the content to set  
\*/  
public void setContent(String Content) \{  
this.Content = Content;  
\}  
  
\}  
  
  
图片消息：  
public class ImageMessage extends BaseMessage \{  
/\*\*  
\* 通过上传多媒体文件，得到的id。  
\*/  
private String MediaId;  
\}  
  
  
音乐消息：  
public class MusicMessage extends BaseMessage \{  
private Music Music;  
  
  
/\*\*  
\* @return the music  
\*/  
public Music getMusic() \{  
return Music;  
\}  
  
  
/\*\*  
\* @param music the music to set  
\*/  
public void setMusic(Music music) \{  
this.Music = music;  
\}  
  
\}  
  
  
public class Music \{  
/\*\*  
\* 音乐标题  
\*/  
private String Title;  
/\*\*  
\* 音乐描述  
\*/  
private String Description;  
/\*\*  
\* 音乐链接  
\*/  
private String MusicUrl;  
/\*\*  
\* 高质量音乐链接，WIFI环境优先使用该链接播放音乐  
\*/  
private String HQMusicUrl;  
/\*\*  
\* 缩略图的媒体id，通过上传多媒体文件，得到的id  
\*/  
private String ThumbMediaId;  
/\*\*  
\* @return the title  
\*/  
public String getTitle() \{  
return Title;  
\}  
/\*\*  
\* @param title the title to set  
\*/  
public void setTitle(String title) \{  
Title = title;  
\}  
/\*\*  
\* @return the description  
\*/  
public String getDescription() \{  
return Description;  
\}  
/\*\*  
\* @param description the description to set  
\*/  
public void setDescription(String description) \{  
Description = description;  
\}  
/\*\*  
\* @return the musicUrl  
\*/  
public String getMusicUrl() \{  
return MusicUrl;  
\}  
/\*\*  
\* @param musicUrl the musicUrl to set  
\*/  
public void setMusicUrl(String musicUrl) \{  
MusicUrl = musicUrl;  
\}  
/\*\*  
\* @return the hQMusicUrl  
\*/  
public String getHQMusicUrl() \{  
return HQMusicUrl;  
\}  
/\*\*  
\* @param musicUrl the hQMusicUrl to set  
\*/  
public void setHQMusicUrl(String musicUrl) \{  
HQMusicUrl = musicUrl;  
\}  
/\*\*  
\* @return the thumbMediaId  
\*/  
public String getThumbMediaId() \{  
return ThumbMediaId;  
\}  
/\*\*  
\* @param thumbMediaId the thumbMediaId to set  
\*/  
public void setThumbMediaId(String thumbMediaId) \{  
ThumbMediaId = thumbMediaId;  
\}  
\}  
  
  
  
  
语音消息：  
public class VoiceMessage extends BaseMessage \{  
/\*\*  
\* 通过上传多媒体文件，得到的id  
\*/  
private String MediaId;  
  
  
/\*\*  
\* @return the mediaId  
\*/  
public String getMediaId() \{  
return MediaId;  
\}  
  
  
/\*\*  
\* @param mediaId the mediaId to set  
\*/  
public void setMediaId(String mediaId) \{  
MediaId = mediaId;  
\}  
  
\}  
  
  
视频消息：  
public class VideoMessage extends BaseMessage \{  
/\*\*  
\* 通过上传多媒体文件，得到的id  
\*/  
private String MediaId;  
/\*\*  
\* 视频消息的标题  
\*/  
private String Title;  
/\*\*  
\* 视频消息的描述  
\*/  
private String Description;  
/\*\*  
\* @return the mediaId  
\*/  
public String getMediaId() \{  
return MediaId;  
\}  
/\*\*  
\* @param mediaId the mediaId to set  
\*/  
public void setMediaId(String mediaId) \{  
MediaId = mediaId;  
\}  
/\*\*  
\* @return the title  
\*/  
public String getTitle() \{  
return Title;  
\}  
/\*\*  
\* @param title the title to set  
\*/  
public void setTitle(String title) \{  
Title = title;  
\}  
/\*\*  
\* @return the description  
\*/  
public String getDescription() \{  
return Description;  
\}  
/\*\*  
\* @param description the description to set  
\*/  
public void setDescription(String description) \{  
Description = description;  
\}  
  
  
\}  
  
  
图文消息：  
public class NewsMessage extends BaseMessage \{  
/\*\*  
\* 图文消息个数，限制为10条以内  
\*/  
private int ArticleCount;  
/\*\*  
\* 多条图文消息信息，默认第一个item为大图,注意，如果图文数超过10，则将会无响应  
\*/  
private List<Articles> Articles;  
/\*\*  
\* @return the articleCount  
\*/  
public int getArticleCount() \{  
return ArticleCount;  
\}  
/\*\*  
\* @param articleCount the articleCount to set  
\*/  
public void setArticleCount(int articleCount) \{  
ArticleCount = articleCount;  
\}  
/\*\*  
\* @return the articles  
\*/  
public List<Articles> getArticles() \{  
return Articles;  
\}  
/\*\*  
\* @param articles the articles to set  
\*/  
public void setArticles(List<Articles> articles) \{  
Articles = articles;  
\}  
  
  
\}  
  
  
public class Articles implements Serializable \{  
/\*\*  
\* 图文消息标题  
\*/  
private String Title;  
/\*\*  
\* 图文消息描述  
\*/  
private String Description;  
/\*\*  
\* 图片链接，支持JPG、PNG格式，较好的效果为大图360\*200，小图200\*200  
\*/  
private String PicUrl;  
/\*\*  
\* 点击图文消息跳转链接  
\*/  
private String Url;  
/\*\*  
\* @return the title  
\*/  
public String getTitle() \{  
return Title;  
\}  
/\*\*  
\* @param title the title to set  
\*/  
public void setTitle(String title) \{  
Title = title;  
\}  
/\*\*  
\* @return the description  
\*/  
public String getDescription() \{  
return Description;  
\}  
/\*\*  
\* @param description the description to set  
\*/  
public void setDescription(String description) \{  
Description = description;  
\}  
/\*\*  
\* @return the picUrl  
\*/  
public String getPicUrl() \{  
return PicUrl;  
\}  
/\*\*  
\* @param picUrl the picUrl to set  
\*/  
public void setPicUrl(String picUrl) \{  
PicUrl = picUrl;  
\}  
/\*\*  
\* @return the url  
\*/  
public String getUrl() \{  
return Url;  
\}  
/\*\*  
\* @param url the url to set  
\*/  
public void setUrl(String url) \{  
Url = url;  
\}  
  
  
\}  
  
  
然后将各个类型的消息Bean到XML的转换方法写到一个工具类中。  
因为XML结构中的内容都包含CDATA，因此需要使xstream支持cdata。  
整个微信消息工具类如下：  
import java.io.IOException;  
import java.io.InputStream;  
import java.io.Writer;  
import java.util.HashMap;  
import java.util.List;  
import java.util.Map;  
  
  
import javax.servlet.http.HttpServletRequest;  
  
  
import org.apache.log4j.Logger;  
import org.dom4j.Document;  
import org.dom4j.DocumentException;  
import org.dom4j.Element;  
import org.dom4j.io.SAXReader;  
  
  
import com.company.project.model.resp.Articles;  
import com.company.project.model.resp.ImageMessage;  
import com.company.project.model.resp.MusicMessage;  
import com.company.project.model.resp.NewsMessage;  
import com.company.project.model.resp.TextMessage;  
import com.company.project.model.resp.VideoMessage;  
import com.company.project.model.resp.VoiceMessage;  
import com.thoughtworks.xstream.XStream;  
import com.thoughtworks.xstream.core.util.QuickWriter;  
import com.thoughtworks.xstream.io.HierarchicalStreamWriter;  
import com.thoughtworks.xstream.io.xml.PrettyPrintWriter;  
import com.thoughtworks.xstream.io.xml.XppDriver;  
  
  
public class MessageUtil \{  
public static final Logger log = Logger.getLogger(MessageUtil.class);  
public static final String MESSAGG\_TYPE\_TEXT = "text";  
public static final String MESSAGG\_TYPE\_IMAGE = "image";  
public static final String MESSAGG\_TYPE\_VOICE = "voice";  
public static final String MESSAGG\_TYPE\_VIDEO = "video";  
public static final String MESSAGG\_TYPE\_LOCATION = "location";  
public static final String MESSAGG\_TYPE\_LINK = "link";  
public static final String MESSAGG\_TYPE\_MUSIC = "music";  
public static final String MESSAGG\_TYPE\_NEWS = "news";  
public static final String MESSAGG\_TYPE\_EVENT = "event";  
// 关注  
public static final String EVENT\_TYPE\_SUBSCRIBE = "subscribe";  
// 取消关注  
public static final String EVENT\_TYPE\_UNSUBSCRIBE = "unsubscribe";  
  
/\*\*  
\* 扩展XStream，使其支持CDATA  
\*/  
private static XStream xStream = new XStream(new XppDriver() \{  
public HierarchicalStreamWriter createWriter(Writer out) \{  
return new PrettyPrintWriter(out) \{  
// 对所有的XML节点增加CDATA标记  
boolean cdata = true;  
  
public void startNode(String name,Class clazz) \{  
super.startNode(name,clazz);  
\}  
  
protected void writeText(QuickWriter writer,String text) \{  
if (cdata) \{  
writer.write("<!\[CDATA\[");  
writer.write(text);  
writer.write("\]\]>");  
\}  
else \{  
writer.write(text);  
\}  
\}  
\};  
\}  
\});  
/\*\*  
\* 解析微信发过来的请求（XML）  
\*  
\* @author qincd  
\* @date Nov 4, 2014 11:03:55 AM  
\*/  
public static Map<String,String> parseXml(HttpServletRequest request) throws IOException, DocumentException \{  
Map<String,String> map = new HashMap<String,String>();  
InputStream input = request.getInputStream();  
SAXReader saxReader = new SAXReader();  
Document document = saxReader.read(input);  
Element root = document.getRootElement();  
List<Element> eles = root.elements();  
for (Element ele:eles) \{  
log.info(ele.getName() + ":" + ele.getText());  
map.put(ele.getName(), ele.getText());  
\}  
  
input.close();  
input = null;  
  
return map;  
\}  
  
public static String textMessageToXml(TextMessage textMessage) \{  
xStream.alias("xml", textMessage.getClass());  
return xStream.toXML(textMessage);  
\}  
  
public static String ImageMessageToXml(ImageMessage imageMessage) \{  
xStream.alias("xml", imageMessage.getClass());  
return xStream.toXML(imageMessage);  
\}  
  
public static String MusicMessageToXml(MusicMessage musicMessage) \{  
xStream.alias("xml", musicMessage.getClass());  
return xStream.toXML(musicMessage);  
\}  
public static String NewsMessageToXml(NewsMessage newsMessage) \{  
xStream.alias("xml", newsMessage.getClass());  
xStream.alias("item", new Articles().getClass());  
return xStream.toXML(newsMessage);  
\}  
public static String videoMessageToXml(VideoMessage videoMessage) \{  
xStream.alias("xml", videoMessage.getClass());  
return xStream.toXML(videoMessage);  
\}  
public static String voiceMessageToXml(VoiceMessage voiceMessage) \{  
xStream.alias("xml", voiceMessage.getClass());  
return xStream.toXML(voiceMessage);  
\}  
\}  
  
  
这些公共的东西可以打成一个Jar包