Java-struts2 之值栈问题

这里是根据一个小项目，将数据库的值查出来，然后在页面前台进行遍历的方法

放入值的几种方式：

Struts2的三种存值取值的方式

值栈:

栈上下文:

ActionContext:

package com.sun.action;

import java.sql.DriverManager;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.util.*;

import javax.servlet.http.HttpServletRequest;

import org.apache.struts2.ServletActionContext;

import com.mysql.jdbc.Connection;

import com.opensymphony.xwork2.ActionContext;

import com.opensymphony.xwork2.ActionSupport;

import com.sun.model.User;

public class UserListAction extends ActionSupport{

	static PreparedStatement ps = null;

    static ResultSet rs;

	 public String execute()throws Exception{

		 Connection con = null;  //创建用于连接数据库的Connection对象

		 List<User> users  = new ArrayList<User>();

      try {

          Class.forName("com.mysql.jdbc.Driver");// 加载Mysql数据驱动  

        con = (Connection) DriverManager.getConnection(

                  "jdbc:mysql://127.0.0.1:3306/test", "root", "123456");// 创建数据连接

           //System.out.println("数据库连接成功");

               String sql = "select * from user";// 删除数据的sql语句

               ps = (PreparedStatement) con.prepareStatement(sql);

              rs = ps.executeQuery();

              User c = null;

	           while(rs.next()){

	        	   c = new User();

	        	   c.setAge(rs.getInt("age"));

	        	   c.setId(rs.getInt("id"));

	        	   c.setName(rs.getString("name"));

	        	   c.setSex(rs.getString("sex"));

	           //System.out.println(rs.getString("name"));

	        	   users.add(c);

	           }

           con.close();   //关闭数据库连接

           } catch (Exception e) {

            System.out.println("数据库连接失败" + e.getMessage());

	      } 

           HttpServletRequest request = ServletActionContext.getRequest();

         //  request.setAttribute("users", users) ;

         //  ActionContext.getContext().put("users", users);

         ActionContext.getContext().getValueStack().push(users);

         ActionContext.getContext().getValueStack().push(users);

		 return "list_ok";

	 }

}

<%@ page language="java" contentType="text/html; charset=utf-8"

    pageEncoding="utf-8"%>

    <%@ taglib prefix="s" uri="/struts-tags"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<meta http-equiv="Content-Type" content="text/html; charset=utf-8">

<title>显示用户的列表</title>

</head>

<body>

<table>

  <tr>

    <th>ID</th>

    <th>姓名</th>

    <th>年龄</th>

    <th>性别</th>

  </tr>

<%-- HttpServletRequest request = ServletActionContext.getRequest();

         //  request.setAttribute("users", users) ;

         <s:iterator value="#request.users" >

  <tr>

    <td><s:property value="id" /></td>

    <td><s:property value="name" /></td>

    <td><s:property value="age" /></td>

    <td><s:property value="sex" /></td>

  </tr>

  </s:iterator> --%>

<%--  ActionContext.getContext().put("users", users); <s:iterator value="#users" var="u">

  <tr>

    <td><s:property value="#u.id" /></td>

    <td><s:property value="#u.name" /></td>

    <td><s:property value="#u.age" /></td>

    <td><s:property value="#u.sex" /></td>

  </tr>

  </s:iterator> --%>

<%--   ActionContext.getContext().getValueStack().push(users); <s:iterator >

  <tr>

    <td><s:property value="id" /></td>

    <td><s:property value="name" /></td>

    <td><s:property value="age" /></td>

    <td><s:property value="sex" /></td>

  </tr>

  </s:iterator> --%>

</table>

</body>

</html>

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Java-struts2 之值栈问题

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