MVC第二篇

MVC实例

现在Javaweb开发第一阶段学习步入实践阶段，在这儿将自己做的项目记下来，也方便积累经验。

下图是处理流程：

MySQL数据库表如下所示：

1.在web项目webContent中新建test.jsp

<%@ 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>

<a href="listAllStudentsServlet">List All Students</a>

</body>
</html>

2在Java-src中新建ListAllStudentServlet.java，并对其进行配置

package com.javaweb.mvc;

import java.io.IOException;
import java.util.Arrays;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class ListAllStudentsServlet extends HttpServlet {
private static final long serialVersionUID = 1L;

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        StudentDao studentDao = new StudentDao();
        List<Student> students = studentDao.getAll();

        request.setAttribute("students", students);
        request.getRequestDispatcher("/students.jsp").forward(request, response);


    }

}

3.继续创建Student.java

package com.javaweb.mvc;

public class Student {
    private Integer id;
    private String studentName;
    private String location;
    private String telephone;

    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getStudentName() {
        return studentName;
    }
    public void setStudentName(String studentName) {
        this.studentName = studentName;
    }
    public String getLocation() {
        return location;
    }
    public void setLocation(String location) {
        this.location = location;
    }
    public String getTelephone() {
        return telephone;
    }
    public void setTelephone(String telephone) {
        this.telephone = telephone;
    }
    public Student(Integer id, String studentName, String location, String telephone) {
        super();
        this.id = id;
        this.studentName = studentName;
        this.location = location;
        this.telephone = telephone;
    }

}

4.创建StudentDao.java

package com.javaweb.mvc;

import java.util.ArrayList;
import java.util.List;
import java.sql.*;

public class StudentDao {

    public List<Student> getAll(){
        List<Student> students = new ArrayList<Student>();
        Connection conn = null;
        PreparedStatement ps = null;
        ResultSet rs = null;

        try {

                Class.forName("com.mysql.jdbc.Driver");

            String url = "jdbc:mysql://localhost:3306/student?user=root&password=1234";
            String user = "root";
            String password = "1234";
            String sql = "select * from stu";
            conn = DriverManager.getConnection(url, user, password);
            ps = conn.prepareStatement(sql);
            rs = ps.executeQuery();
            while(rs.next()){
                int id = rs.getInt(1);
                String studentName = rs.getString(2);
                String location = rs.getString(3);
                String telephone = rs.getString(4);

                Student student = new Student(id, studentName, location, telephone);

                students.add(student);
            }

        }catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            try {
                if(rs != null)
                    rs.close();
                if(ps != null)
                    ps.close();
                if(conn != null)
                    conn.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }

        return students;
    }

}

5.在webContent中新建students.jsp

<%-- 显示学生信息 --%>
<%@page import="java.util.List"%>
<%@page import="com.javaweb.mvc.Student" %>
<%@ 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>

    <%
        List<Student> students = (List<Student>)request.getAttribute("students");

    %>
    <table>
        <tr>
            <th>id</th>
            <th>studentName</th>
            <th>location</th>
            <th>telephone</th>
        </tr>

        <%
            for(Student student:students){
        %>
            <tr>
                <td><%= student.getId() %></td>
                <td><%= student.getStudentName() %></td>
                <td><%= student.getLocation() %></td>
                <td><%= student.getTelephone() %></td>
            </tr>
        <%
            }
        %>

    </table>

</body>
</html>

6.添加JDBC驱动

添加在lib文件夹，因为lib文件夹中存放支持web应用运行的JAR文件

7.接下来就可以运行了

这是运行结果：