Java反射机制实现微信公众平台XML数据解析

在做微信公众平台开发时，接收消息中有很多种类型的xml消息，比如“文本消息”“图片消息”“语音消息”“视频消息”“链接消息”“地理位置消息”等等，最初在开发时针对每一种数据格式写了一个实体类，单独做解析，当然这样写的好处是层次分明。但经过尝试之后，用一个统一的实体类消息做处理，更加高效，当然，里面最核心的就是在遍历xml数据时，通过反射的机制动态调用set方法：

1、ReceiveXmlEntity.java实体类。包含了所有的接收到的xml字段

package com.basicwechat.entity;
/**
 * 接收到的微信xml实体类
 * @author pamchen-1
 *
 */
public class ReceiveXmlEntity {
	private String ToUserName="";
	private String FromUserName="";
	private String CreateTime="";
	private String MsgType="";
	private String MsgId="";
	private String Event="";
	private String EventKey="";
	private String Ticket="";
	private String Latitude="";
	private String Longitude="";
	private String Precision="";
	private String PicUrl="";
	private String MediaId="";
	private String Title="";
	private String Description="";
	private String Url="";
	private String Location_X="";
	private String Location_Y="";
	private String Scale="";
	private String Label="";
	private String Content="";
	private String Format="";
	private String Recognition="";

	public String getRecognition() {
		return Recognition;
	}
	public void setRecognition(String recognition) {
		Recognition = recognition;
	}
	public String getFormat() {
		return Format;
	}
	public void setFormat(String format) {
		Format = format;
	}
	public String getContent() {
		return Content;
	}
	public void setContent(String content) {
		Content = content;
	}
	public String getLocation_X() {
		return Location_X;
	}
	public void setLocation_X(String locationX) {
		Location_X = locationX;
	}
	public String getLocation_Y() {
		return Location_Y;
	}
	public void setLocation_Y(String locationY) {
		Location_Y = locationY;
	}
	public String getScale() {
		return Scale;
	}
	public void setScale(String scale) {
		Scale = scale;
	}
	public String getLabel() {
		return Label;
	}
	public void setLabel(String label) {
		Label = label;
	}
	public String getTitle() {
		return Title;
	}
	public void setTitle(String title) {
		Title = title;
	}
	public String getDescription() {
		return Description;
	}
	public void setDescription(String description) {
		Description = description;
	}
	public String getUrl() {
		return Url;
	}
	public void setUrl(String url) {
		Url = url;
	}
	public String getPicUrl() {
		return PicUrl;
	}
	public void setPicUrl(String picUrl) {
		PicUrl = picUrl;
	}
	public String getMediaId() {
		return MediaId;
	}
	public void setMediaId(String mediaId) {
		MediaId = mediaId;
	}
	public String getEventKey() {
		return EventKey;
	}
	public void setEventKey(String eventKey) {
		EventKey = eventKey;
	}
	public String getTicket() {
		return Ticket;
	}
	public void setTicket(String ticket) {
		Ticket = ticket;
	}
	public String getLatitude() {
		return Latitude;
	}
	public void setLatitude(String latitude) {
		Latitude = latitude;
	}
	public String getLongitude() {
		return Longitude;
	}
	public void setLongitude(String longitude) {
		Longitude = longitude;
	}
	public String getPrecision() {
		return Precision;
	}
	public void setPrecision(String precision) {
		Precision = precision;
	}
	public String getEvent() {
		return Event;
	}
	public void setEvent(String event) {
		Event = event;
	}
	public String getMsgId() {
		return MsgId;
	}
	public void setMsgId(String msgId) {
		MsgId = msgId;
	}
	public String getToUserName() {
		return ToUserName;
	}
	public void setToUserName(String toUserName) {
		ToUserName = toUserName;
	}
	public String getFromUserName() {
		return FromUserName;
	}
	public void setFromUserName(String fromUserName) {
		FromUserName = fromUserName;
	}
	public String getCreateTime() {
		return CreateTime;
	}
	public void setCreateTime(String createTime) {
		CreateTime = createTime;
	}
	public String getMsgType() {
		return MsgType;
	}
	public void setMsgType(String msgType) {
		MsgType = msgType;
	}
}

2、ParseReceiveXml.hava 通过反射的机制动态调用set方法，将xml消息转成实体类，避免大批量的if重复判断。

package com.basicwechat.parse;

import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.Iterator;
import org.dom4j.Document;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;

import com.basicwechat.entity.ReceiveXmlEntity;
/**
 * 解析接收到的微信xml，返回消息对象
 * @author pamchen-1
 *
 */
public class ParseReceiveXml {
	/**
	 * 解析微信xml消息
	 * @param strXml
	 * @return
	 */
	public ReceiveXmlEntity getMsgEntity(String strXml){
		ReceiveXmlEntity msg = null;
		try {
			if (strXml.length() <= 0 || strXml == null)
				return null;

			// 将字符串转化为XML文档对象
			Document document = DocumentHelper.parseText(strXml);
			// 获得文档的根节点
			Element root = document.getRootElement();
			// 遍历根节点下所有子节点
			Iterator<?> iter = root.elementIterator();

			// 遍历所有结点
			msg = new ReceiveXmlEntity();
			//利用反射机制，调用set方法
			//获取该实体的元类型
			Class<?> c = Class.forName("com.basicwechat.entity.ReceiveXmlEntity");
			msg = (ReceiveXmlEntity)c.newInstance();//创建这个实体的对象

			while(iter.hasNext()){
				Element ele = (Element)iter.next();
				//获取set方法中的参数字段（实体类的属性）
				Field field = c.getDeclaredField(ele.getName());
				//获取set方法，field.getType())获取它的参数数据类型
				Method method = c.getDeclaredMethod("set"+ele.getName(), field.getType());
				//调用set方法
				method.invoke(msg, ele.getText());
			}
		} catch (Exception e) {
			// TODO: handle exception
			System.out.println("xml 格式异常: "+ strXml);
			e.printStackTrace();
		}
		return msg;
	}
}

Java反射机制实现微信公众平台XML数据解析