实体:
private String foodName;// 餐品名称public String getFoodName() {
return foodName;
} public void setFoodName(String foodName) {
this.foodName = foodName;
}
select :
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException { response.setContentType("text/html;charset=utf-8");
request.setCharacterEncoding("utf-8");
String username=request.getParameter("txtloginid");
String pwd=request.getParameter("txtpass");
UserInfo u=new UserInfo(username,pwd);
UserInfo userInfo=UserInfoDao.findUserInfoByUsernameAndPassword(u);
try {
if (username.equals(userInfo.getLoginname())&&pwd.equals(userInfo.getLoginpass())) {
//如果用户存在查询所有餐品并跳转到show页面
List<FoodInfo> list=FoodInfoDao.findAllFoodInfo();
HttpSession session=request.getSession();
session.setAttribute("FoodInfo", list);
response.sendRedirect("main/show.jsp");
}else {
response.sendRedirect("login.jsp");
}
} catch (RuntimeException e) {
// TODO Auto-generated catch block
e.printStackTrace();
response.sendRedirect("login.jsp");
}
}show页面:
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8" isELIgnored="false" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %><c:forEach items="FoodInfo" var="falg" varStatus="status"><td class="tdcls" valign="top">
<b>${falg.foodName }</b><br>
<font color="gray" >限价:人民币
<font color="red">13</font> 元</font><br>
</td></c:forEach>
错误:严重: Servlet.service() for servlet jsp threw exception
javax.servlet.jsp.el.ELException: Unable to find a value for "foodName" in object of class "java.lang.String" using operator "."
at org.apache.commons.el.Logger.logError(Logger.java:481)
at org.apache.commons.el.Logger.logError(Logger.java:498)
at org.apache.commons.el.Logger.logError(Logger.java:611)
at org.apache.commons.el.ArraySuffix.evaluate(ArraySuffix.java:340)
at org.apache.commons.el.ComplexValue.evaluate(ComplexValue.java:145)
。。
private String foodName;// 餐品名称public String getFoodName() {
return foodName;
} public void setFoodName(String foodName) {
this.foodName = foodName;
}
select :
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException { response.setContentType("text/html;charset=utf-8");
request.setCharacterEncoding("utf-8");
String username=request.getParameter("txtloginid");
String pwd=request.getParameter("txtpass");
UserInfo u=new UserInfo(username,pwd);
UserInfo userInfo=UserInfoDao.findUserInfoByUsernameAndPassword(u);
try {
if (username.equals(userInfo.getLoginname())&&pwd.equals(userInfo.getLoginpass())) {
//如果用户存在查询所有餐品并跳转到show页面
List<FoodInfo> list=FoodInfoDao.findAllFoodInfo();
HttpSession session=request.getSession();
session.setAttribute("FoodInfo", list);
response.sendRedirect("main/show.jsp");
}else {
response.sendRedirect("login.jsp");
}
} catch (RuntimeException e) {
// TODO Auto-generated catch block
e.printStackTrace();
response.sendRedirect("login.jsp");
}
}show页面:
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8" isELIgnored="false" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %><c:forEach items="FoodInfo" var="falg" varStatus="status"><td class="tdcls" valign="top">
<b>${falg.foodName }</b><br>
<font color="gray" >限价:人民币
<font color="red">13</font> 元</font><br>
</td></c:forEach>
错误:严重: Servlet.service() for servlet jsp threw exception
javax.servlet.jsp.el.ELException: Unable to find a value for "foodName" in object of class "java.lang.String" using operator "."
at org.apache.commons.el.Logger.logError(Logger.java:481)
at org.apache.commons.el.Logger.logError(Logger.java:498)
at org.apache.commons.el.Logger.logError(Logger.java:611)
at org.apache.commons.el.ArraySuffix.evaluate(ArraySuffix.java:340)
at org.apache.commons.el.ComplexValue.evaluate(ComplexValue.java:145)
。。
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使用打印system.out.println(request.getSession(). getAttribute("FoodInfo"));是否存在
<c:forEach items="${FoodInfo}" var="falg" varStatus="status"><td class="tdcls" valign="top">
<b>${falg.foodName }</b><br>
<font color="gray" >限价:人民币
<font color="red">13</font> 元</font><br>
</td></c:forEach>试试 迭代内容用el
items 是从作用域里去取值的
这里应该是里list没有找到值引发的异常
或者session 中存进去的值就是空的
<c:forEach items="${sessionScope.FoodInfo}" var="falg" varStatus="status"> <td class="tdcls" valign="top">
<b>${falg.foodName } </b> <br>
<font color="gray" >限价:人民币
<font color="red">13 </font> 元 </font> <br>
</td> </c:forEach>
你是把FoodInfo放在session 在session取下看看没用,或者看下list是否有值,试试debug调试