微信公众号--被动回复用户消息

https://www.bilibili.com/video/BV1nb411P76t?p=7

以图文消息为例

1、创建对应的实体：

public class ResponseMessage {
     private String toUserName;
     private String fromUserName;
     private String createTime;
     public ResponseMessage(Map<String, String> requestMap) { // 这个是用户发送的消息的一个Map
         this.toUserName = requestMap.get("FromUserName"); 
         this.fromUserName = requestMap.get("ToUserName");
         this.createTime = System.currentTimeMillis()/1000+"";
     }
}
public class NewsResponseMessage extends ResponseMessage {
    private String msgType;
    private String articleCount;
    private List<Article> articles = new ArrayList<>();
    private Article article;
    public NewsResponseMessage(Map requestMap, List<Article> articles) {
        super(requestMap);
        articles = articles;
        articleCount = "" + articles.size() + "";
        msgType = "news"; 
    }
}    
public class Article {
    private String title;
    private String description;
    private String picUrl;
    private String url;
    public Article(String title, String description, String picUrl, String url) {
        this.title = title;
        this.description = description;
        this.picUrl = picUrl;
        this.url = url;
    }
}

2、将NewsResponseMessage类转化成对应的xml

https://developers.weixin.qq.com/doc/offiaccount/Message_Management/Passive_user_reply_message.html  微信开发文档 

使用@XStreamAlias()方式

准备工作：需要三个jar包： xmlpull  xpp3   xstream

链接：https://pan.baidu.com/s/12QM_INm7A26ZxolBlf1JXA  提取码：xdep 

对照图文消息的xml的格式，在对应的实体上加上注解@XStreamAlias("")

public class ResponseMessage {
    @XStreamAlias("ToUserName") // 这个名称就是在xml里面会显示的标签的名称
    private String toUserName;
    @XStreamAlias("FromUserName")
    private String fromUserName;
    @XStreamAlias("CreateTime")
    private String createTime;
    public ResponseMessage(Map<String, String> requestMap) {
        this.toUserName = requestMap.get("FromUserName");  
        this.fromUserName = requestMap.get("ToUserName");
        this.createTime = System.currentTimeMillis()/1000+"";
    }
}

@XStreamAlias("xml")  // 要将这个类转换成xml格式   写在类外面的这个 会是转换成xml格式后的最外面的大标签
public class NewsResponseMessage extends ResponseMessage {
    @XStreamAlias("ArticleCount")
    private String articleCount;
    @XStreamAlias("Articles") // 
    private List<Article> articles = new ArrayList<>();
    private Article article;
        @XStreamAlias("MsgType")
        private String msgType
    public NewsResponseMessage(Map requestMap, List<Article> articles) {
        super(requestMap);
        articles = articles;
        articleCount = "" + articles.size() + "";
                msgType = "news";
    }
}    

@XStreamAlias("item")
public class Article {
    @XStreamAlias("Title")
    private String title;
    @XStreamAlias("Description")
    private String description;
    @XStreamAlias("PicUrl")
    private String picUrl;
    @XStreamAlias("Url")
    private String url;

    public Article(String title, String description, String picUrl, String url) {
        this.title = title;
        this.description = description;
        this.picUrl = picUrl;
        this.url = url;
    }
}

3、将实例转换成xml：

public static String beanToXml(ResponseMessage ResponseMessage) {
    XStream xStream = new XStream();
    // 在解析之前先开启注解
    xStream.processAnnotations(NewsResponseMessage.class);
    String xml = xStream.toXML(ResponseMessage);
    return xml;
}