微信公众平台开发学习记录(3)————接收消息和发送回复消息

当普通微信用户向公众账号发消息时，微信服务器将POST消息的XML数据包到开发者填写的URL上。

当用户发送消息给公众号时（或某些特定的用户操作引发的事件推送时），会产生一个POST请求，开发者可以在响应包（Get）中返回特定XML结构，来对该消息进行响应（现支持回复文本、图片、图文、语音、视频、音乐）。严格来说，发送被动响应消息其实并不是一种接口，而是对微信服务器发过来消息的一次回复。回复消息是根据接收的xml中获取到用户信息，根据各类型消息XML结构示例进行拼接。

代码：

package com.qs.action;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.io.PrintWriter;import java.util.Date;import javax.servlet.ServletInputStream;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.apache.struts2.interceptor.ServletRequestAware;import org.apache.struts2.interceptor.ServletResponseAware;import com.opensymphony.xwork2.ActionSupport;import com.qs.util.SignUtil;/** * @author qiaoshuai * @createDate 2016-3-1 */public class TestWeiXinAction extends ActionSupport implementsServletRequestAware, ServletResponseAware {private static final long serialVersionUID = -799327593656049028L;protected HttpServletRequest request;private HttpServletResponse response;public void setServletResponse(HttpServletResponse response) {this.response = response;}public void setServletRequest(HttpServletRequest request) {this.request = request;}public void checkSignature() throws IOException {boolean isGet = request.getMethod().toLowerCase().equals("get");if (isGet) {// 微信加密签名String signature = request.getParameter("signature");System.out.println("signature=" + signature);// 时间戳String timestamp = request.getParameter("timestamp");System.out.println("timestamp=" + timestamp);// 随机数String nonce = request.getParameter("nonce");System.out.println("nonce=" + nonce);// 随机字符串String echostr = request.getParameter("echostr");System.out.println("echostr=" + echostr);PrintWriter out = response.getWriter();// 通过检验signature对请求进行校验，若校验成功则原样返回echostr，表示接入成功，否则接入失败if (SignUtil.checkSignature(signature, timestamp, nonce)) {out.print(echostr);}out.close();out = null;} else {// POSTresponseMsg();}}public void responseMsg() throws  IOException{String outString = "";String replyString = "";BufferedReader br = new BufferedReader(new InputStreamReader((ServletInputStream) request.getInputStream(), "utf-8"));String line = null;StringBuilder sb = new StringBuilder();while ((line = br.readLine()) != null) {sb.append(line);}String xmlS = sb.toString();System.out.println(xmlS);if (xmlS != null && !xmlS.equals("")) {// 用户发送者int fromuser_s = xmlS.indexOf("<FromUserName><![CDATA[");int fromuser_e = xmlS.indexOf("]]></FromUserName>");String fromuser = xmlS.substring(fromuser_s + 23, fromuser_e);System.out.println("fromuser:" + fromuser);// 取出目标用户int touser_s = xmlS.indexOf("<ToUserName><![CDATA[");int touser_e = xmlS.indexOf("]]></ToUserName>");String touser = xmlS.substring(touser_s + 21, touser_e);System.out.println("touser:" + touser);// 获取请求类型int msgType_s = xmlS.indexOf("<MsgType><![CDATA[");int msgType_e = xmlS.indexOf("]]></MsgType>");String msgType = xmlS.substring(msgType_s + 18, msgType_e);System.out.println("msgType:" + msgType);// 获取请求当前时间int createTime_s = xmlS.indexOf("<CreateTime>");int createTime_e = xmlS.indexOf("</CreateTime>");String createTime = xmlS.substring(createTime_s + 12, createTime_e);int createTimeInt = Integer.parseInt(createTime);System.out.println("createTime:" + createTimeInt);// 接收点击推事件消息if ("event".equals(msgType)) {StringBuilder outBuilder = new StringBuilder();int EventKey_s = xmlS.indexOf("<EventKey><![CDATA[");int EventKey_e = xmlS.indexOf("]]></EventKey>");String eventKey = xmlS.substring(EventKey_s + 19, EventKey_e);System.out.println("EventKey:" + eventKey);if (eventKey.equals("V1001_TODAY_MUSIC")) { //outBuilder.append("《燕归巢》");outString = textDemo(outBuilder.toString());}else if(eventKey.equals("V1001_GOOD")){outBuilder.append("谢谢您的赞！");outString = textDemo(outBuilder.toString());}}// 接收文本消息if ("text".equals(msgType)) {StringBuilder outBuilder = new StringBuilder();int content_s = xmlS.indexOf("<Content><![CDATA[");int content_e = xmlS.indexOf("]]></Content>");String content = xmlS.substring(content_s + 18, content_e);System.out.println("content:" + content);if (content.equals("天气")) { // 帮助回复（文本回复）outBuilder.append("今天是晴天");outString = textDemo(outBuilder.toString());}else{outBuilder.append(content + "啊哈");outString = textDemo(outBuilder.toString());}}//replyString = this.replyDemo(fromuser, touser, outString);}System.out.println("replyString:" + replyString);this.print(replyString);}// 向请求端发送返回数据public void print(String content) {try {response.setContentType("text/html;charset=utf-8");response.getWriter().print(content);response.getWriter().flush();response.getWriter().close();} catch (Exception e) {e.printStackTrace();}}public String replyDemo(String fromuser, String touser, String content) {StringBuilder outString = new StringBuilder();// 表头outString.append("<xml>");outString.append("    <ToUserName><![CDATA[" + fromuser+ "]]></ToUserName>");outString.append("    <FromUserName><![CDATA[" + touser+ "]]></FromUserName>");outString.append("    <CreateTime>" + new Date().getTime()+ "</CreateTime>");// 表中outString.append(content);// 表尾outString.append("    <FuncFlag>0</FuncFlag>");outString.append("</xml>");return outString.toString();}/** *文本回复 Demo *  * @param content *            字符串内容 **/public String textDemo(String content) {StringBuilder textString = new StringBuilder();textString.append("<MsgType><![CDATA[text]]></MsgType>");textString.append("<Content><![CDATA[").append(content).append("]]></Content>");return textString.toString();}/** *图文回复 Demo *  * @param title *            标题 * @param description *            简介内容 * @param picUrl *            图片路径 * @param skipUrl *            链接路径 *  **/public String textPicDemo(String title, String description, String picUrl,String skipUrl) {StringBuilder textPicString = new StringBuilder();textPicString.append("  <MsgType><![CDATA[news]]></MsgType>");textPicString.append("  <ArticleCount>1</ArticleCount>");textPicString.append("  <Articles>");textPicString.append("    <item>");textPicString.append("      <Title><![CDATA[" + title + "]]></Title> ");if (description != null) {textPicString.append("      <Description><![CDATA[" + description+ "]]></Description>");}textPicString.append("    <PicUrl><![CDATA[" + picUrl + "]]></PicUrl>");textPicString.append("      <Url><![CDATA[" + skipUrl + "]]></Url>");textPicString.append("    </item>");textPicString.append("  </Articles>");return textPicString.toString();}/** * 多张图文回复 Demo *  * @param articleCount *            图文数量 * @param content *            图文内容 **/public String textPicListDemosun(String[] titles, String[] descriptions,String[] picUrls, String[] skipUrls) {StringBuilder textPicString = new StringBuilder();textPicString.append("  <MsgType><![CDATA[news]]></MsgType>");textPicString.append("  <ArticleCount>" + 1 + "</ArticleCount>");textPicString.append("  <Articles>");textPicString.append("    <item>");textPicString.append("      <Title><![CDATA[" + titles[0]+ "]]></Title> ");if (descriptions != null) {textPicString.append("      <Description><![CDATA["+ descriptions[0] + "]]></Description>");}textPicString.append("    <PicUrl><![CDATA[" + picUrls[0]+ "]]></PicUrl>");textPicString.append("      <Url><![CDATA[" + skipUrls[0] + "]]></Url>");textPicString.append("    </item>");textPicString.append("  </Articles>");return textPicString.toString();}/** * 多张图文回复 Demo *  * @param articleCount *            图文数量 * @param content *            图文内容 **/public String textPicListDemo(int articleCount, String content) {StringBuilder textPicString = new StringBuilder();textPicString.append("  <MsgType><![CDATA[news]]></MsgType>");textPicString.append("  <ArticleCount>" + articleCount+ "</ArticleCount>");textPicString.append("  <Articles>");textPicString.append(content);textPicString.append("  </Articles>");return textPicString.toString();}}

效果：