移动开发:微信公众平台消息接口-java-jsp版(转)
转载自：http://blog.csdn.net/wangqianjiao/article/details/8469780
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微信公众平台现在推出自动回复消息接口，但是由于是接口内容用的是PHP语言写的，很多地方操作起来让本人这个对java比较熟悉的小伙很别扭，所以仿照PHP的接口代码做了一套jsp语言编写的接口。
首先先把整个接口代码贴出来做下比较，然后我们再分析代码：
PHP代码：
<?php/** * wechat php test *///define your tokendefine("TOKEN", "weixin");$wechatObj = new wechatCallbackapiTest();$wechatObj->valid();class wechatCallbackapiTest{public function valid() { $echoStr = $_GET["echostr"]; //valid signature , option if($this->checkSignature()){ echo $echoStr; exit; } } public function responseMsg() {//get post data, May be due to the different environments$postStr = $GLOBALS["HTTP_RAW_POST_DATA"]; //extract post dataif (!empty($postStr)){ $postObj = simplexml_load_string($postStr, 'SimpleXMLElement', LIBXML_NOCDATA); $fromUsername = $postObj->FromUserName; $toUsername = $postObj->ToUserName; $keyword = trim($postObj->Content); $time = time(); $textTpl = "<xml><ToUserName><![CDATA[%s]]></ToUserName><FromUserName><![CDATA[%s]]></FromUserName><CreateTime>%s</CreateTime><MsgType><![CDATA[%s]]></MsgType><Content><![CDATA[%s]]></Content><FuncFlag>0</FuncFlag></xml>"; if(!empty( $keyword )) { $msgType = "text"; $contentStr = "Welcome to wechat world!"; $resultStr = sprintf($textTpl, $fromUsername, $toUsername, $time, $msgType, $contentStr); echo $resultStr; }else{ echo "Input something..."; } }else { echo ""; exit; } }private function checkSignature(){ $signature = $_GET["signature"]; $timestamp = $_GET["timestamp"]; $nonce = $_GET["nonce"]; $token = TOKEN;$tmpArr = array($token, $timestamp, $nonce);sort($tmpArr);$tmpStr = implode( $tmpArr );$tmpStr = sha1( $tmpStr );if( $tmpStr == $signature ){return true;}else{return false;}}}?>?
JAVA代码：
<%@page import="java.util.Date"%><%@page import="org.dom4j.Element"%><%@page import="org.dom4j.DocumentHelper"%><%@page import="org.dom4j.Document"%><%@page import="java.io.IOException"%><%@page import="java.io.InputStreamReader"%><%@page import="java.io.BufferedReader"%><%@page import="java.io.Reader"%><%@page import="java.security.MessageDigest"%><%@page import="java.util.Arrays"%><%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%><%//WeiXinHandler为内部类不能使用非final类型的对象final String TOKEN="weixin";final HttpServletRequest final_request=request; final HttpServletResponse final_response=response;%><% class WeiXinHandler{public void valid(){String echostr=final_request.getParameter("echostr");if(null==echostr||echostr.isEmpty()){responseMsg();}else{if(this.checkSignature()){this.print(echostr);}else{this.print("error"); }}}//自动回复内容public void responseMsg(){String postStr=null;try{postStr=this.readStreamParameter(final_request.getInputStream());}catch(Exception e){e.printStackTrace();}//System.out.println(postStr);if (null!=postStr&&!postStr.isEmpty()){Document document=null;try{document = DocumentHelper.parseText(postStr);}catch(Exception e){e.printStackTrace();}if(null==document){this.print("");return;}Element root=document.getRootElement(); String fromUsername = root.elementText("FromUserName"); String toUsername = root.elementText("ToUserName"); String keyword = root.elementTextTrim("Content"); String time = new Date().getTime()+""; String textTpl = "<xml>"+"<ToUserName><![CDATA[%1$s]]></ToUserName>"+"<FromUserName><![CDATA[%2$s]]></FromUserName>"+"<CreateTime>%3$s</CreateTime>"+"<MsgType><![CDATA[%4$s]]></MsgType>"+"<Content><![CDATA[%5$s]]></Content>"+"<FuncFlag>0</FuncFlag>"+"</xml>"; if(null!=keyword&&!keyword.equals("")) { String msgType = "text"; String contentStr = "Welcome to wechat world!"; String resultStr = textTpl.format(textTpl, fromUsername, toUsername, time, msgType, contentStr); this.print(resultStr); }else{ this.print("Input something..."); } }else { this.print(""); }}//微信接口验证public boolean checkSignature(){String signature = final_request.getParameter("signature"); String timestamp = final_request.getParameter("timestamp"); String nonce = final_request.getParameter("nonce"); String token=TOKEN; String[] tmpArr={token,timestamp,nonce}; Arrays.sort(tmpArr); String tmpStr=this.ArrayToString(tmpArr); tmpStr=this.SHA1Encode(tmpStr); if(tmpStr.equalsIgnoreCase(signature)){return true;}else{return false;}}//向请求端发送返回数据public void print(String content){try{final_response.getWriter().print(content);final_response.getWriter().flush();final_response.getWriter().close();}catch(Exception e){}}//数组转字符串public String ArrayToString(String [] arr){StringBuffer bf = new StringBuffer();for(int i = 0; i < arr.length; i++){ bf.append(arr[i]);}return bf.toString();}//sha1加密public String SHA1Encode(String sourceString) {String resultString = null;try { resultString = new String(sourceString); MessageDigest md = MessageDigest.getInstance("SHA-1"); resultString = byte2hexString(md.digest(resultString.getBytes()));} catch (Exception ex) {}return resultString;}public final String byte2hexString(byte[] bytes) {StringBuffer buf = new StringBuffer(bytes.length * 2);for (int i = 0; i < bytes.length; i++) {if (((int) bytes[i] & 0xff) < 0x10) { buf.append("0"); }buf.append(Long.toString((int) bytes[i] & 0xff, 16));}return buf.toString().toUpperCase();}//从输入流读取post参数public String readStreamParameter(ServletInputStream in){StringBuilder buffer = new StringBuilder();BufferedReader reader=null;try{reader = new BufferedReader(new InputStreamReader(in));String line=null;while((line = reader.readLine())!=null){buffer.append(line); }}catch(Exception e){e.printStackTrace();}finally{if(null!=reader){try {reader.close();} catch (IOException e) {e.printStackTrace();}}}return buffer.toString();}}%><%WeiXinHandler handler=new WeiXinHandler();handler.valid();%>?
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以上就是PHP接口和JSP接口的所有代码，现在我们来对一些需要注意的地方做下分析：
首先的从总体看的话，jsp要比PHP繁琐一些，因为很多函数需要自己写，像sha1加密，解析xml字符串等都需要自己找第三方的库。
第一点，我们要获取微信公众平台给jsp发送的post或get参数，正常情况下都是用request.getParameter就可以获取到，但是在写的过程中发现PHP是这样获取
$postStr = $GLOBALS["HTTP_RAW_POST_DATA"];
?这时通过查询一些资料知道这样获取的是无法通过$_GET或$_POST函数得到的”未识别 MIME 类型的数据“，原始的 POST 数据
（参考：http://blog.csdn.net/china_skag/article/details/7284227）
所以这里使用获取原始数据流的方式来解析post的xml数据
String postStr=null;try{postStr=this.readStreamParameter(final_request.getInputStream());}catch(Exception e){e.printStackTrace();}?
//从输入流读取post参数public String readStreamParameter(ServletInputStream in){StringBuilder buffer = new StringBuilder();BufferedReader reader=null;try{reader = new BufferedReader(new InputStreamReader(in));String line=null;while((line = reader.readLine())!=null){buffer.append(line); }}catch(Exception e){e.printStackTrace();}finally{if(null!=reader){try {reader.close();} catch (IOException e) {e.printStackTrace();}}}return buffer.toString();}?第二个，是response消息返回给微信平台，我尝试的用最一般的out.print去做，但是发现没反应，观察PHP的代码写法
echo "";exit;
?猜想可能需要有个刷新的操作才能把消息response回去，于是找了下response内的一些函数做出以下尝试
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//向请求端发送返回数据public void print(String content){try{final_response.getWriter().print(content);final_response.getWriter().flush();final_response.getWriter().close();}catch(Exception e){}}?发现以上做法是可以在微信发送端得到消息的；
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第三个，接口描述上说目前只支持80端口的服务端地址，所以我这里的做法是用apache服务器路由到tomcat的jsp上
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关于微信公众平台的消息接口的详细介绍，可以参看微信公众平台的官方文档，里面介绍了消息的xml的格式和消息的发送方式等。
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