Java web--MVC开发模式介绍

怼烎@ 2023-02-13 03:35 2阅读 0赞

在开发web应用程序时，通常需要同时使用3种技术，并分别承担不同的职责。**jsp**一般来编写用户界面层的信息显示，充当视图层的角色（简称：V）；**servlet**需要来扮演任务的执行者，一般充当控制层的角色（简称：C）；**Javabean**主要实现业务逻辑的处理，充当模型层的角色（简称：M）。这些分工就如同流水线一般，不同的人有不同的任务，承担不同的责任。通过这三种技术的组合实现不同组件功能分工协作，将一个系统的功能分为3种不同类型的组件，这种技术通常称为MVC模式。

**目录**

一、jsp技术

二、Javabean技术

三、servlet技术

四、简单的MVC开发模式介绍

五、基于MVC技术+Dao技术的学生信息管理系统的设计（Dao技术是一种数据库连接技术）

--------------------

### 一、jsp技术 ###

jsp是一种运行在服务器端的脚本语言，它是用来开发动态网页的技术，是Java web程序开发的重要技术。与jsp相反的就是HTML，它是一种静态网络开发技术。

如果你已经知道了MVC开发模式，想来你应该也已经知道了jsp技术。

如果你不知道的话，那么你可以到菜鸟教程网站或者w3school网站去学习，通过百度就可以查到，这些网站讲的都比较好。

### 二、Javabean技术 ###

Javaweb是用Java语言编写的、遵循一定标准的类，他封装了数据和业务逻辑，完成数据封装和数据处理等功能。

详情可见：

java web--javabean技术：[https://blog.csdn.net/qq\_43238335/article/details/105701359][https_blog.csdn.net_qq_43238335_article_details_105701359]

### 三、servlet技术 ###

Servlet技术是一种Java语言编写的服务器端程序，是由服务器端调用和执行的、按照servlet自身规范编写的Java。servlet可以处理客户端传来的http请求，并返回一个响应。

详情可见：

java web--Servlet技术（一）：[https://blog.csdn.net/qq\_43238335/article/details/105964695][https_blog.csdn.net_qq_43238335_article_details_105964695]

java web--Servlet技术（二）：[https://blog.csdn.net/qq\_43238335/article/details/106138427][https_blog.csdn.net_qq_43238335_article_details_106138427]

### 四、简单的MVC开发模式介绍 ###

输入圆的半径，求得圆的周长和面积

简单的分为四个部分：两个jsp文件、一个Javabean文件、一个servlet文件。

jsp完成数据的获取和显示，Javabean完成业务逻辑的处理，servlet完成具体的功能。

1.jsp获取数据

2.javabean业务逻辑

package aaa;
    
    public class a02a {
    private double radius;
    
    public a02a() {
    	super();
    	// TODO Auto-generated constructor stub
    }
    
    public a02a(double radius) {
    	super();
    	this.radius = radius;
    }
    
    public double getRadius() {
    	return radius;
    }
    
    public void setRadius(double radius) {
    	this.radius = radius;
    }
    public double mj()
    {
    	return Math.PI*radius*radius;
    }
    public double zc()
    {
    	return Math.PI*2*radius;
    }
    }

3.servlet 具体的完成功能，计算出圆的周长和面积

package aaa;
    
    import java.io.IOException;
    import javax.servlet.ServletException;
    import javax.servlet.annotation.WebServlet;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    /**
     * Servlet implementation class a02b
     */
    @WebServlet("/a02b")
    public class a02b extends HttpServlet {
    	private static final long serialVersionUID = 1L;
           
        /**
         * @see HttpServlet#HttpServlet()
         */
        public a02b() {
            super();
            // TODO Auto-generated constructor stub
        }
    
    	/**
    	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
    	 */
    	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    		// TODO Auto-generated method stub
    		doPost(request,response);
    	}
    
    	/**
    	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
    	 */
    	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    		// TODO Auto-generated method stub
    		String number=request.getParameter("radius");
    		double r=Double.parseDouble(number);
    		a02a aa=new a02a(r);
    		double mj=aa.mj();
    		double zc=aa.zc();
    		request.setAttribute("mj", mj);
    		request.setAttribute("zc", zc);
    		request.getRequestDispatcher("/a02/a02d.jsp").forward(request, response);
    	}
    
    }

4.jsp数据显示

### 五、基于MVC技术+Dao技术的学生信息管理系统的设计（Dao技术是一种数据库连接技术） ###

我通过Dao技术连接的是MySQL的数据库。

以下是管理系统的流程和结构（仅为查询模块，其余模块与查询模块相同）

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQzMjM4MzM1_size_16_color_FFFFFF_t_70][]

1.javabean部分

//User.java文件
    
    package bean1;
    
    public class User {
    	private int id;
    	private String name;
    	private String sex;
    	private int age;
    	private double weight;
    	private double height;
    	public User() {
    		super();
    		// TODO Auto-generated constructor stub
    	}
    	public User(int id, String name, String sex, int age, double weight, double height) {
    		super();
    		this.id = id;
    		this.name = name;
    		this.sex = sex;
    		this.age = age;
    		this.weight = weight;
    		this.height = height;
    	}
    	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 getSex() {
    		return sex;
    	}
    	public void setSex(String sex) {
    		this.sex = sex;
    	}
    	public int getAge() {
    		return age;
    	}
    	public void setAge(int age) {
    		this.age = age;
    	}
    	public double getWeight() {
    		return weight;
    	}
    	public void setWeight(double weight) {
    		this.weight = weight;
    	}
    	public double getHeight() {
    		return height;
    	}
    	public void setHeight(double height) {
    		this.height = height;
    	}
    }

2.Dao部分

//db.properties文件
    driver=com.mysql.jdbc.Driver
    url=jdbc:mysql://localhost:3306/aaa?useUnicode=true&characterEncoding=UTF-8
    user=root
    password=2411030483
    
    
    //JdbcUtil.java文件
    package bean1;
    
    import java.io.IOException;
    import java.sql.Connection;
    import java.sql.DriverManager;
    import java.sql.ResultSet;
    import java.sql.SQLException;
    import java.sql.Statement;
    import java.util.Properties;
    
    public class JdbcUtil {
    	private static String driver;
    	private static String url;
    	private static String user;
    	private static String password;
    	private static Properties pr=new Properties();
    	public JdbcUtil(){
    		super();
    	}
    	static 
    	{
    		try {
    			pr.load(JdbcUtil.class.getClassLoader().getResourceAsStream("db.properties"));
    		    driver=pr.getProperty("driver");
    		    url=pr.getProperty("url");
    		    user=pr.getProperty("user");
    		    password=pr.getProperty("password");
    		    try {
    				Class.forName(driver);
    			} catch (ClassNotFoundException e) {
    				// TODO Auto-generated catch block
    				e.printStackTrace();
    			}
    		} catch (IOException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}
    	}
    	public static Connection getConnection() throws SQLException
    	{
    		return DriverManager.getConnection(url,user,password);
    	}
    	public static void free(Connection conn,Statement st,ResultSet rs) throws Exception
    	{
    		if(conn!=null){conn.close();}
    		if(st!=null){st.close();}
    		if(rs!=null){rs.close();}
    	}
    }
    
    //UserDao.java文件
    package bean1;
    
    import com.mysql.jdbc.Connection;
    import com.mysql.jdbc.PreparedStatement;
    import java.sql.*;
    import java.util.ArrayList;
    import java.util.List;
    
    public class UserDao {
    public int add(User user)throws Exception
    {
    	Connection conn=(Connection) JdbcUtil.getConnection();
    	String sql="insert into biao1(id,name,sex,age,weight,height) values(?,?,?,?,?,?);";
    	PreparedStatement pstmt=(PreparedStatement) conn.prepareStatement(sql);
    	pstmt.setInt(1,user.getId());//将第一个占位符赋值
    	pstmt.setString(2,user.getName());
    	pstmt.setString(3,user.getSex());
    	pstmt.setInt(4,user.getAge());
    	pstmt.setDouble(5,user.getWeight());
    	pstmt.setDouble(6,user.getHeight());
    	int n=pstmt.executeUpdate();
    	JdbcUtil.free(conn,pstmt,null);
    	return n;
    }
    public int update(User user)throws Exception
    {
    	Connection conn=(Connection) JdbcUtil.getConnection();
    	String sql="update biao1 set id=?,name=?,sex=?,age=?,weight=?,height=? where name=? and sex=?"; 
    	PreparedStatement pstmt=(PreparedStatement) conn.prepareStatement(sql);
    	pstmt.setInt(1,user.getId());//将第一个占位符赋值
    	pstmt.setString(2,user.getName());
    	pstmt.setString(3,user.getSex());
    	pstmt.setInt(4,user.getAge());
    	pstmt.setDouble(5,user.getWeight());
    	pstmt.setDouble(6,user.getHeight());
    	pstmt.setString(7,user.getName());
    	pstmt.setString(8,user.getSex());
    	int n=pstmt.executeUpdate();
    	JdbcUtil.free(conn,pstmt,null);
    	return n;
    }
    public int delete(String name,String sex,double weight1,double weight2)throws Exception
    {
    	Connection conn=(Connection) JdbcUtil.getConnection();
    	String sql="delete from biao1 where name=?,sex=?,weight>=? and weight<=?;";
    	PreparedStatement pstmt=(PreparedStatement) conn.prepareStatement(sql);
    	pstmt.setString(1,name);
    	pstmt.setString(2,sex);
    	pstmt.setDouble(3,weight1);
    	pstmt.setDouble(4,weight2);
    	int n=pstmt.executeUpdate();
    	JdbcUtil.free(conn,pstmt,null);
    	return n;
    }
    public List<User> findUserById(double weight1,double weight2)throws Exception
    {
    	Connection conn=(Connection) JdbcUtil.getConnection();
    	User user=null;
    	List<User> userList=new ArrayList<User>();
    	String sql = "select id,name,sex,age,weight,height from biao1 where weight>=? and weight<=?;";//写出对数据库的操作语句，？表示占位符
    	PreparedStatement pstmt=(PreparedStatement) conn.prepareStatement(sql);
    	pstmt.setDouble(1,weight1);
    	pstmt.setDouble(2,weight2);
    	ResultSet rs=pstmt.executeQuery();
    	while(rs.next())
    	{
    		user=new User();
    		user.setId(rs.getInt("id"));
    		user.setName(rs.getString("name"));
    		user.setSex(rs.getString("sex"));
    		user.setAge(rs.getInt("age"));
    		user.setWeight(rs.getDouble("weight"));
    		user.setHeight(rs.getDouble("height"));
    		userList.add(user);
    	}
    	JdbcUtil.free(conn,pstmt,rs);
    	return userList;
    }
    public List<User> QueryAll() throws Exception
    {
    	Connection conn=(Connection) JdbcUtil.getConnection();
    	User user=null;
    	List<User> userList=new ArrayList<User>();
    	String sql="select * from biao1";
    	PreparedStatement pstmt=(PreparedStatement) conn.prepareStatement(sql);
    	ResultSet rs=pstmt.executeQuery();
    	while(rs.next())
    	{
    		user=new User();
    		user.setId(rs.getInt("id"));
    		user.setName(rs.getString("name"));
    		user.setSex(rs.getString("sex"));
    		user.setAge(rs.getInt("age"));
    		user.setWeight(rs.getDouble("weight"));
    		user.setHeight(rs.getDouble("height"));
    		userList.add(user);
    	}
    	JdbcUtil.free(conn,pstmt,rs);
    	return userList;
    }
    }

3.servlet部分

//a01a_delete2.java文件
    package bean1;
    
    import java.io.IOException;
    import javax.servlet.ServletException;
    import javax.servlet.annotation.WebServlet;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    /**
     * Servlet implementation class a01a_delete2
     */
    @WebServlet("/a01a_delete2")
    public class a01a_delete2 extends HttpServlet {
    	private static final long serialVersionUID = 1L;
           
        /**
         * @see HttpServlet#HttpServlet()
         */
        public a01a_delete2() {
            super();
            // TODO Auto-generated constructor stub
        }
    
    	/**
    	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
    	 */
    	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    		// TODO Auto-generated method stub
    		doPost(request, response);
    		}
    
    	/**
    	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
    	 */
    	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    		// TODO Auto-generated method stub
    		request.setCharacterEncoding("UTF-8");
    		String name=request.getParameter("name");
    		String sex=request.getParameter("sex");
    		String ww1=request.getParameter("w1");
    		String ww2=request.getParameter("w2");
    		double weight1=Double.parseDouble(ww1);
    		double weight2=Double.parseDouble(ww2);
    		UserDao dao=new UserDao();
    		try {
    			int n=dao.delete(name, sex, weight1, weight2);
    			request.setAttribute("number", n);
    		} catch (Exception e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}
    		request.getRequestDispatcher("/a01a_delete/a01a_delete3.jsp").forward(request,response);
    		}
    }
    
    
    //a01a_insert2.jsp文件
    package bean1;
    
    import java.io.IOException;
    
    import javax.servlet.ServletException;
    import javax.servlet.annotation.WebServlet;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    /**
     * Servlet implementation class a01a_insert2
     */
    @WebServlet("/a01a_insert2")
    public class a01a_insert2 extends HttpServlet {
    	private static final long serialVersionUID = 1L;
           
        /**
         * @see HttpServlet#HttpServlet()
         */
        public a01a_insert2() {
            super();
            // TODO Auto-generated constructor stub
        }
    
    	/**
    	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
    	 */
    	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    		// TODO Auto-generated method stub
    		doPost(request, response);
    	}
    
    	/**
    	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
    	 */
    	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    		// TODO Auto-generated method stub
    		request.setCharacterEncoding("UTF-8");
    		String id=request.getParameter("id_in");
    		String name=request.getParameter("name_in");
    		String sex=request.getParameter("sex_in");
    		String age=request.getParameter("age_in");
    		String weight=request.getParameter("weight_in");
    		String height=request.getParameter("height_in");//通过表单获取数据
    		int id2=Integer.parseInt(id);//将数据转换为相应类型
    		int age2=Integer.parseInt(age);
    		double weight2=Double.parseDouble(weight);
    		double height2=Double.parseDouble(height);
    		User user=new User(id2,name,sex,age2,weight2,height2);
    		UserDao dao=new UserDao();
    		try {
    			int n=dao.add(user);
    			request.setAttribute("number", n);
    		} catch (Exception e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}
    		request.getRequestDispatcher("/a01a_insert/a01a_insert3.jsp").forward(request,response);
    		}
    }
    
    
    //a01a_select2.java文件
    package bean1;
    
    import java.io.IOException;
    import java.util.List;
    
    import javax.servlet.ServletException;
    import javax.servlet.annotation.WebServlet;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    /**
     * Servlet implementation class a01a_select2
     */
    @WebServlet("/a01a_select2")
    public class a01a_select2 extends HttpServlet {
    	private static final long serialVersionUID = 1L;
           
        /**
         * @see HttpServlet#HttpServlet()
         */
        public a01a_select2() {
            super();
            // TODO Auto-generated constructor stub
        }
    
    	/**
    	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
    	 */
    	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    		// TODO Auto-generated method stub
    		doPost(request, response);
    	}
    
    	/**
    	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
    	 */
    	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    		// TODO Auto-generated method stub
    		request.setCharacterEncoding("UTF-8");
    		String weight1 = request.getParameter("weight1");//通过表单获取数据
    		String weight2 = request.getParameter("weight2");
    		double wt1 = Double.parseDouble(weight1);
    		double wt2 = Double.parseDouble(weight2);//将数据转换为相应类型
    		UserDao dao=new UserDao();
    		try {
    			List<User> user=dao.findUserById(wt1, wt2);
    			request.setAttribute("list", user);
    		} catch (Exception e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}
    		request.getRequestDispatcher("/a01a_select/a01a_select3.jsp").forward(request,response);
    		}
    }
    
    
    //a01a_update.java文件
    package bean1;
    
    import java.io.IOException;
    import javax.servlet.ServletException;
    import javax.servlet.annotation.WebServlet;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    /**
     * Servlet implementation class a01a_update2
     */
    @WebServlet("/a01a_update2")
    public class a01a_update2 extends HttpServlet {
    	private static final long serialVersionUID = 1L;
           
        /**
         * @see HttpServlet#HttpServlet()
         */
        public a01a_update2() {
            super();
            // TODO Auto-generated constructor stub
        }
    
    	/**
    	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
    	 */
    	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    		// TODO Auto-generated method stub
    		doPost(request, response);
    	}
    
    	/**
    	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
    	 */
    	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    		// TODO Auto-generated method stub
    		request.setCharacterEncoding("UTF-8");
    		int id2=Integer.parseInt(request.getParameter("id"));
    		String name2=request.getParameter("name");
    		String sex2=request.getParameter("sex");
    		int age2=Integer.parseInt(request.getParameter("age"));
    		double weight2=Double.parseDouble(request.getParameter("weight"));
    		double height2=Double.parseDouble(request.getParameter("height"));
    		UserDao dao=new UserDao();
    		User user=new User(id2,name2,sex2,age2,weight2,height2);
    		try {
    			int n=dao.update(user);
    			request.setAttribute("number", n);
    		} catch (Exception e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}
    		request.getRequestDispatcher("/a01a_update/a01a_update3.jsp").forward(request,response);
    		}
    }

4.jsp部分

<%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8"%>
    <!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>删除信息页面</title>
    </head>
    <body>
    <p>请写入删除信息</p>
    <hr>
    <form action="../a01a_delete2" method="post"><%//创建表单传输数据 %>
    姓名： <input type="text" name="name"><br><br>
    性别：
     男<input type="radio" name="sex" value="男">
     女<input type="radio" name="sex" value="女"><br><br>
    体重范围：<p>
    最低体重： <input type="text" name="w1"><br><br>
    最高体重： <input type="text" name="w2"><br><br>
    <input type="submit" value="确认">
     <input type="reset" value="取消">
    </form><br>
    </body>
    </html>
    
    
    
    <%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8"%>
    <!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>删除界面</title>
    </head>
    <body>
    <p>删除界面</p>
    <hr>
    <%
    String a=request.getAttribute("number").toString();
    int aa=Integer.parseInt(a);
    if(aa>0) out.println("删除成功");
    else out.println("删除失败");
    %> 
    </body>
    </html>
    
    
    
    <%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8"%>
    <!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>插入信息页面</title>
    </head>
    <body>
    <p>请写入插入信息</p>
    <hr>
    <form action="../a01a_insert2" method="post"><%//创建表单传输数据 %>
    序号： <input type="text" name="id_in"><br><br>
    姓名： <input type="text" name="name_in"><br><br>
    性别： <input type="text" name="sex_in"><br><br>
    年龄： <input type="text" name="age_in"><br><br>
    体重： <input type="text" name="weight_in"><br><br>
    身高： <input type="text" name="height_in"><br><br>
    <input type="submit" value="确认">
     <input type="reset" value="取消">
    </form><br>
    </body>
    </html>
    
    
    
    <%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8"%>
    <!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>插入界面</title>
    </head>
    <body>
    <p>插入界面</p>
    <hr>
    <%
    String a=request.getAttribute("number").toString();
    int aa=Integer.parseInt(a);
    if(aa>0) out.println("插入成功");
    else out.println("插入失败");
    %> 
    </body>
    </html>
    
    
    
    
    <%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8"%>
    <!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>查询信息页面</title>
    </head>
    <body>
    <form action="../a01a_select2" method="post"><%//创建表单传输数据 %>
    <p>请选择想要查询的分数范围</p>
    <hr>
    最低体重： <input type="text" name="weight1"><br><br>
    最高体重： <input type="text" name="weight2"><br><br>
    <input type="submit" value="提交">
     <input type="reset" value="取消">
    </form><br>
    </body>
    </html>
    
    
    
    <%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8"%>
        <%@ page import="java.util.List"%>
         <%@ page import="bean1.a01a_select2"%>
          <%@ page import="bean1.User"%>
    <!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>查询页面</title>
    </head>
    <body>
    <p>查询页面</p>
    <hr/>
    <table>
    <tr>
    			<td>学号</td>
    			<td>姓名</td>
    			<td>性别</td>
    			<td>年龄</td>
    			<td>体重</td>
    			<td>身高</td>
    		</tr>
    <%List<User> list2=(List<User>)(request.getAttribute("list"));
    for(int i=0;i<list2.size();i++)
    {
    	User u=list2.get(i);
    %>
    <tr>
    			<td><%=u.getId()%></td>
    			<td><%=u.getName()%></td>
    			<td><%=u.getSex()%></td>
    			<td><%=u.getAge()%></td>
    			<td><%=u.getHeight()%></td>
    			<td><%=u.getHeight()%></td>
    		</tr>
    <%
    }
    %>
    </table>
    </body>
    </html>
    
    
    
    <%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8"%>
    <!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>修改信息页面</title>
    </head>
    <body>
    <p>请写入修改信息</p>
    <hr>
    <form action="../a01a_update2" method="post">
    		<table>
    			<tr>
    				<td>学号</td>
    				<td><input type="text" name="id" ></td>
    			</tr>
    			<tr>
    				<td>姓名</td>
    				<td><input type="text" name="name"></td>
    			</tr>
    			<tr>
    				<td>性别</td>
    				<td><input type="text" name="sex"></td>
    			</tr>
    			<tr>
    				<td>年龄</td>
    				<td><input type="text" name="age"></td>
    			</tr>
    			<tr>
    				<td>体重</td>
    				<td><input type="text" name="weight"></td>
    			</tr>
    			<tr>
    				<td>身高</td>
    				<td><input type="text" name="height"></td>
    			</tr>
    			<tr align="center">
    				<td><input type="submit" value="确认"></td>
    				<td><input type="reset" value="取消"></td>
    			</tr>
    		</table>
    	</form>
    </body>
    </html>
    
    
    
    <%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8"%>
    <!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>更新界面</title>
    </head>
    <body>
    <p>更新界面</p>
    <hr>
    <%
    String a=request.getAttribute("number").toString();
    int aa=Integer.parseInt(a);
    if(aa>0) out.println("更新成功");
    else out.println("更新失败");
    %> 
    </body>
    </html>

5.管理页面

<%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8"%>
    <!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>学生身体体质信息管理系统</title>
    </head>
    <frameset rows="80,*">
    <frame src="indextitle.jsp" scrolling="no">
    <frameset cols="140,*">
    <frame src="indexleft.jsp" scrolling="no">
    <frame src="indexright.jsp" name="right" scrolling="no">
    </frameset>
    </frameset>
    </html>
    
    
    <%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8"%>
    <!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>菜单页面</title>
    </head>
    <body>
    <br><br><br><br>
    <p><a href="../a01a_insert/a01a_insert1.jsp" target="right">添加学生</a></p>
    <p><a href="../a01a_delete/a01a_delete1.jsp" target="right">按条件删除学生</a></p>
    <p><a href="../a01a_select/a01a_select1.jsp" target="right">按条件查询学生</a></p>
    <p><a href="../a01a_update/a01a_update1.jsp" target="right">按条件修改学生</a></p>
    </body>
    </html>
    
    
    <%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8"%>
    <!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>Insert title here</title>
    </head>
    <body background="1.jpg">
    </body>
    </html>
    
    
    <%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8"%>
    <!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>页面标题</title>
    </head>
    <body>
    <center><h1>学生身体体质信息管理系统</h1></center>
    </body>
    </html>

运行示例如下：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQzMjM4MzM1_size_16_color_FFFFFF_t_70 1][]

[https_blog.csdn.net_qq_43238335_article_details_105701359]: https://blog.csdn.net/qq_43238335/article/details/105701359
[https_blog.csdn.net_qq_43238335_article_details_105964695]: https://blog.csdn.net/qq_43238335/article/details/105964695
[https_blog.csdn.net_qq_43238335_article_details_106138427]: https://blog.csdn.net/qq_43238335/article/details/106138427
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQzMjM4MzM1_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20200527091037761.jpg?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQzMjM4MzM1,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQzMjM4MzM1_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/20200527092701699.jpg?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQzMjM4MzM1,size_16,color_FFFFFF,t_70