http://wenku.baidu.com/view/2ddf3843be1e650e52ea99e5.html
json调用jsp页面，jsp页面中加载公司标签的实现过程(json 异步)

1、jsp中写的json：

var isAskUrl = "<c:url value='/ask/ajax/isAskJson.shtm'  />"    
         $.getJSON(isAskUrl,{userID:hiddenUserId,faqPrice:price,ranNum:Math.random()},function(data){
            if(data != 1 ){
                alert("金额不足，不能提问！");
            }else{

            }
        });




2、要访问的isAskJson.jsp页面

<%@ page language="java" contentType="text/html; charset=UTF-8"
     pageEncoding="UTF-8"%>
 <%@ include file="/WEB-INF/jsp/common/common.jsp" %>
 <%@ taglib tagdir="/WEB-INF/tags/fee" prefix="fee" %>
 <%@ include file="/WEB-INF/jsp/login/loginCheck.jsp" %>  


 <fee:isAsk var="result" userID="${param.userID}" faqPrice="${param.faqPrice}"></fee:isAsk>
 <c:if test="${not empty result and result eq 1}">
     <util:writeJson value="[1]"></util:writeJson>
 </c:if>
 <c:if test="${empty result or  result ne 1}">
     <util:writeJson value="[0]"></util:writeJson>
 </c:if>



3、isAsk.tag 的代码

<%@ attribute
     name="userID"
     type="java.lang.Integer"
     required="true"
  %>
  <%@ attribute
     name="faqPrice"
     type="java.lang.Float"
     required="true"
  %>
 <%@ 
     attribute
     name="var"
     type="java.lang.String"
     required="true"
 %>

 <%@ tag 
     import="com.huabeisai.rad3.ibatis2.SqlMapTemplate,com.huabeisai.fee.domain.UserAccount,
     javax.servlet.jsp.PageContext,java.util.*"
     dynamic-attributes="dynamicAttributes"
     description="是否可以提问" %>
 <%
     Integer userID = (Integer)jspContext.getAttribute("userID");
     Float faqPrice = (Float)jspContext.getAttribute("faqPrice");
     
     int rtInt = 0;
     
     if(userID == null){
         return;
     }
     
     if(faqPrice == null || faqPrice < 0){
         return;
     }
     
     Map paramMap = new HashMap();
     paramMap.put("userID",userID);
     paramMap.put("accountID",1);
     UserAccount userAccount = (UserAccount)SqlMapTemplate.selectObject("fee","ns.op.feeApi.getUserAccount",paramMap);
     
     if(userAccount != null && userAccount.getUsableMoney() != null && userAccount.getUsableMoney() > 0){
         Float usableMoney = userAccount.getUsableMoney();
         
         if(usableMoney >= faqPrice){
             rtInt = 1;
         }else {
             rtInt = 0;
         }
     }else{
         rtInt = 0;
     }
     
     jspContext.setAttribute(var,rtInt,PageContext.REQUEST_SCOPE);
 %>

 

 

第二版不用数据库的异步交互过程：

 

<%@ page language="java" contentType="text/html; charset=UTF-8"
     pageEncoding="UTF-8"%>
 <%@ include file="/WEB-INF/jsp/common/common.jsp" %>
 <%@ taglib uri="http://java.sun.com/jsp/jstl/functions" prefix="fn" %>
 <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
 <%@ taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt" %>
 <%@ taglib uri="http://java.sun.com/jsp/jstl/sql" prefix="sql" %>
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 <html>
 <head>
  <script src="http://code.jquery.com/jquery-latest.min.js"></script>
 </head>
 <script>
      function ckc(vl){
      var isAskUrl = "<c:url value='/ask/ajax/isJson.shtm'  />" 
      var numh=vl.value;
      $.getJSON(isAskUrl,{numh:numh,ranNum:Math.random()},function(data){
         document.getElementById("inputid").value=data;
       });
     }
 </script>

 <body>
 <input  type="text" value="" onpropertychange="ckc(this);"/><br></br>
 <input type="text" value="" id="inputid"/>
 </body>
 </html>

2、要访问的isJson.jsp页面

 

<%@ page language="java" contentType="text/html; charset=UTF-8"
     pageEncoding="UTF-8"%>
 <%@ include file="/WEB-INF/jsp/common/common.jsp" %>
 <%@ taglib tagdir="/WEB-INF/tags/fee" prefix="fee" %>
 <%
 int paramvalue=Integer.parseInt(request.getParameter("numh"));
 %>

 <util:writeJson value="[111]"></util:writeJson>