循环输出

使用foreach循环输出List中的数据

步骤详解：
1.数据库的设计和实现
2. Java代码的书写
3. jsp页面的显示

效果图展示

数据库数据
在这里插入图片描述
查询结果的显示

功能分析：

链接数据库
查找数据库内容
把这些内容放入List数组里面
用session传递
jsp页面获取session内容
用foreach循环输出内容

了解一下目录结构吧！
在这里插入图片描述
==注意：==写代码之前一定要添加相应的架包

代码展示

数据库链接（（util包里的DBUtil.java代码））

package com.hnpi.util;import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;public class DBUtil {public static Connection getConn(){String url = "jdbc:sqlserver://localhost:1433;databaseName=Manager";String user = "sa";String pwd = "1";Connection conn = null;try {Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");conn = DriverManager.getConnection(url, user, pwd);} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (ClassNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();}return conn;}public static void closeConn(Connection conn, PreparedStatement ps, ResultSet rs){if(conn!=null){try {conn.close();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}if(ps!=null){try {ps.close();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}if(rs!=null){try {rs.close();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}}

People类的实现（（bean包里的People.java代码））

package com.hnpi.bean;public class People {private int id;private String name;private String pwd;private String reallyName;private String branch;private String role;public int getId() {return id;}public void setId(int id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getPwd() {return pwd;}public void setPwd(String pwd) {this.pwd = pwd;}public String getReallyName() {return reallyName;}public void setReallyName(String reallyName) {this.reallyName = reallyName;}public String getBranch() {return branch;}public void setBranch(String branch) {this.branch = branch;}public String getRole() {return role;}public void setRole(String role) {this.role = role;}public People() {super();// TODO Auto-generated constructor stub}public People(int id, String name, String pwd, String reallyName,String branch, String role) {super();this.id = id;this.name = name;this.pwd = pwd;this.reallyName = reallyName;this.branch = branch;this.role = role;}}

查询内容并用session传输（（servlet包里的UserSelectServlet.java代码））

package com.hnpi.servlet;import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;import com.hnpi.bean.People;
import com.hnpi.util.DBUtil;public class UserSelectServlet extends HttpServlet {public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {doPost(request, response);}public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {request.setCharacterEncoding("utf-8");response.setContentType("text/html");Connection conn = DBUtil.getConn();PreparedStatement ps = null;ResultSet rs = null;String sql = "select * from register";List<People> peoples = new ArrayList<People>();try {ps = conn.prepareStatement(sql);rs = ps.executeQuery();while(rs.next()){People people = new People(rs.getInt(1),rs.getString(2),rs.getString(3),rs.getString(4),rs.getString(5),rs.getString(6));peoples.add(people);}} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}finally{DBUtil.closeConn(conn, ps, rs);}HttpSession session = request.getSession();session.setAttribute("peopleList", peoples);response.sendRedirect("userSelect.jsp");}}

最后是jsp页面的展示（（userSelect.jsp代码））

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@page import="com.hnpi.bean.People"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html><head><base href="<%=basePath%>"><title>My JSP 'regist.jsp' starting page</title><meta http-equiv="pragma" content="no-cache"><meta http-equiv="cache-control" content="no-cache"><meta http-equiv="expires" content="0">    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"><meta http-equiv="description" content="This is my page"><!--<link rel="stylesheet" type="text/css" href="styles.css">--></head><body><table><thead><tr><th>序号</th><th>姓名</th><th>密码</th><th>真实姓名</th><th>部门</th><th>角色</th><th colspan="2">操作</th></tr></thead><tbody><%List<People> peoples = (List)session.getAttribute("peopleList");for(People people :peoples){%><tr><td><%=people.getId() %></td><td><%=people.getName() %></td><td><%=people.getPwd() %></td><td><%=people.getReallyName() %></td><td><%=people.getBranch() %></td><td><%=people.getRole() %></td><td><a href="#">删除</a></td><td><a href="#">更新</a></td></tr><%}%></tbody></table></body>
</html>