基于Java Web的学生管理系统

零、前提

使用工具：idea、MySQL

使用技术：JDBC、servlet

一、数据库

Database - test1 # 数据库：test1

CREATE TABLE student (
id int(3) NOT NULL auto_increment,
name varchar(10) default NULL,
age int(3) default NULL,
classes varchar(10) default NULL,
PRIMARY KEY (id),
UNIQUE KEY index_1 (name)
) ENGINE=InnoDB DEFAULT CHARSET=utf8; # 表：student

insert into student(id,name,age,classes) values (7,'李让',28,'毕业'),(8,'张三',20,'大二'),(9,'张四',10,'三年级'),(11,'小张',10,'三年级'),(12,'张丹',17,'高二'),(13,'小暇',19,'大一'),(14,'小兰',19,'大一'),(15,'李杯狐',12,'五年级'); #表中的内容

二、项目框架

2-1 domain-Student 实体类

public class Student {
    private int id;
    private String name;
    private int age;
    private String classes;

    public Student() {
    }

    public Student(String name, int age, String classes) {
        this.name = name;
        this.age = age;
        this.classes = classes;
    }

    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 int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getClasses() {
        return classes;
    }

    public void setClasses(String classes) {
        this.classes = classes;
    }
}

2-2 util-JdbcUtils 工具类

public class JdbcUtils {
    private final static String url = "jdbc:mysql://localhost:3306/test1?useUnicode=true&characterEncoding=utf8";
    private final static String user = "root";
    private final static String psw = "mysql";

    public static Connection getConn() {
        Connection conn = null;
        try {
            Class.forName("com.mysql.jdbc.Driver");
            conn = DriverManager.getConnection(url, user, psw);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return conn;
    }
}

2-3 dao-StudentDao接口

public interface StudentDao {
    public List<Student> findAll() throws SQLException, ClassNotFoundException;

    public Student findById(int id) throws SQLException, ClassNotFoundException;

    public int add(Student s) throws SQLException, ClassNotFoundException;

    public int delete(int id) throws SQLException, ClassNotFoundException;

    public int modify(int id ,Student s) throws SQLException, ClassNotFoundException;
}

2-4 dao-impl-StudentDaoImpl 接口实现

public class StudentDaoImpl implements StudentDao {
    private Connection conn = null;
    private PreparedStatement ps = null;
    private ResultSet rs = null;
    @Override
    public List<Student> findAll() throws SQLException, ClassNotFoundException {
        conn= JdbcUtils.getConn();
        String sql = "select * from student";
        ps = conn.prepareStatement(sql);
        rs = ps.executeQuery();
        List<Student> list = new ArrayList<Student>();
        while(rs.next()){
            Student s = new Student();
            s.setId(rs.getInt("id"));
            s.setAge(rs.getInt("age"));
            s.setClasses(rs.getString("classes"));
            s.setName(rs.getString("name"));
            list.add(s);
        }
        return list;
    }

    @Override
    public Student findById(int id) throws SQLException, ClassNotFoundException {
        conn= JdbcUtils.getConn();
        String sql = "select * from student where id = ?";
        ps = conn.prepareStatement(sql);
        ps.setInt(1,id);
        rs = ps.executeQuery();
        Student s = new Student();
        while(rs.next()){
            s.setId(rs.getInt("id"));
            s.setAge(rs.getInt("age"));
            s.setClasses(rs.getString("classes"));
            s.setName(rs.getString("name"));
        }
        return s;
    }

    @Override
    public int add(Student s) throws SQLException, ClassNotFoundException {
        conn= JdbcUtils.getConn();
        String sql = "insert into student(name,age,classes) values(?,?,?)";
        ps = conn.prepareStatement(sql);
        ps.setString(1,s.getName());
        ps.setInt(2,s.getAge());
        ps.setString(3,s.getClasses());
        int i = ps.executeUpdate();
        return i;
    }

    @Override
    public int delete(int id) throws SQLException, ClassNotFoundException {
        conn= JdbcUtils.getConn();
        String sql = "delete from student where id = ?";
        ps = conn.prepareStatement(sql);
        ps.setInt(1,id);
        int i = ps.executeUpdate();
        return i;
    }

    @Override
    public int modify(int id, Student s) throws SQLException, ClassNotFoundException {
        conn= JdbcUtils.getConn();
        String sql = "update student set name=?,age=?,classes=? where id=?";
        ps = conn.prepareStatement(sql);
        ps.setString(1,s.getName());
        ps.setInt(2,s.getAge());
        ps.setString(3,s.getClasses());
        ps.setInt(4,id);
        int i = ps.executeUpdate();
        return i;
    }
}

2-5 servle-StudentServlet

public class StudentServlet extends HttpServlet {
    StudentDao studentDao = new StudentDaoImpl();

    public List<Student> findAll() throws SQLException, ClassNotFoundException {
        return studentDao.findAll();
    }
    public int modify(int id ,Student s) throws SQLException, ClassNotFoundException {
        return studentDao.modify(id,s);
    }

    public Student findById(int id) throws SQLException, ClassNotFoundException {
        return studentDao.findById(id);
    }

    public int add(Student s) throws SQLException, ClassNotFoundException{
        return studentDao.add(s);
    }

    public int delete(int id) throws SQLException, ClassNotFoundException{
        return studentDao.delete(id);
    }
} 

2-5 servle-StudentServletAdd

@WebServlet("/stu_add")
public class StudentServletAdd extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doPost(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("utf8");  //解决乱码
        StudentServlet ss = new StudentServlet();
        String name = req.getParameter("name");
        String age = req.getParameter("age");
        String classes = req.getParameter("classes");
        Student s = new Student(name,Integer.parseInt(age),classes);
        try {
            ss.add(s);
        } catch (SQLException throwables) {
            throwables.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
        resp.sendRedirect("/five/stu_list.jsp");
    }
}

2-6 web-stu_list.jsp

<%@ page import="cn.my.sms.servlet.StudentServlet" %>
<%@ page import="cn.my.sms.domain.Student" %>
<%@ page import="java.util.List" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>学生界面</title>
</head>
<body>
    <h2 align="center">学生系统管理</h2>
    <p align="center">欢迎你：XX &nbsp;&nbsp;&nbsp;&nbsp; <a href="login.html">安全退出</a></p>
    <hr/>
    <p align="center"><a href="stu_add.jsp">添加学生</a></p>
    <form action="#" method="post">
        <table align="center" border="1px" width="80%">
            <tr>
                <td>学号</td>
                <td>姓名</td>
                <td>年龄</td>
                <td>班级</td>
                <td>操作</td>
            </tr>
            <%
                StudentServlet ss = new StudentServlet();
                List<Student> list = ss.findAll();
                for(Student s:list){
            %>

            <tr>
                <td><%= s.getId() %></td>
                <td><%= s.getName() %></td>
                <td><%= s.getAge() %></td>
                <td><%= s.getClasses() %></td>
                <td>
                    <a href="stu_delete?id=<%= s.getId() %>" onclick="return confirm('真的要删除该学生吗？')">删除</a>|
                    <a href="stu_modify.jsp?id=<%= s.getId() %>">修改</a> </td>
            </tr>

            <%
                }
            %>

           </table>
       </form>
</body>
</html>

2-6 web-stu_add.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>添加学生界面</title>
</head>
<body>
<form action="stu_add" method="post">
    <table align="center" border="1px">
        <tr>
            <td>姓名</td>
            <td><input type="text" name="name"></td>
        </tr>
        <tr>
            <td>年龄</td>
            <td><input type="text" name="age"></td>
        </tr>
        <tr>
            <td>班级</td>
            <td><input type="text" name="classes"> </td>
        </tr>
        <tr>
            <td align="center" colspan="2"><input type="submit" value="添加学生"></td>
        </tr>
    </table>
</form>
</body>
</html>

2-7 servlet-StudentServletDelete

@WebServlet("/stu_delete")
public class StudentServletDelete extends HttpServlet {
   StudentServlet ss = new StudentServlet();

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doPost(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String id = req.getParameter("id");
        System.out.println("id = " + id);
        int i = 0;
        try {
            i = ss.delete(Integer.parseInt(id));
        } catch (Exception e) {
            e.printStackTrace();
        }

        resp.sendRedirect("/five/stu_list.jsp");

    }
}

2-8 servlet-StudentServletModify

@WebServlet("/stu_modify")
public class StudentServletModify extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doPost(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("utf8");
        String id = req.getParameter("id");
        String name = req.getParameter("name");
        String age = req.getParameter("age");
        String classes = req.getParameter("classes");
        Student s = new Student(name,Integer.parseInt(age),classes);
        StudentServlet ss = new StudentServlet();
        try {
            ss.modify(Integer.parseInt(id),s);
        } catch (Exception throwables) {
            throwables.printStackTrace();
        }
        resp.sendRedirect("stu_list.jsp");
    }
}

2-9 web-stu_modify.jsp

<%@ page import="cn.my.sms.servlet.StudentServlet" %>
<%@ page import="cn.my.sms.domain.Student" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>修改学生</title>
</head>
<body>
<form action="stu_modify" method="post">
    <%
        String id = request.getParameter("id");
        StudentServlet ss = new StudentServlet();
        Student s = ss.findById(Integer.parseInt(id));
    %>
    <input type="hidden" name="id" value="<%= s.getId() %>">
    <table align="center" border="1px">
        <tr>
            <td>姓名</td>
            <td><input type="text" name="name" value="<%= s.getName() %>"></td>
        </tr>
        <tr>
            <td>年龄</td>
            <td><input type="text" name="age" value="<%= s.getAge() %>"></td>
        </tr>
        <tr>
            <td>班级</td>
            <td><input type="text" name="classes" value="<%= s.getClasses() %>"> </td>
        </tr>
        <tr>
            <td align="center" colspan="2"><input type="submit" value="修改学生"></td>
        </tr>
    </table>
</form>
</body>
</html>

三、总结

3-1 根据数据库创建实体类；

3-2 写工具类，获得 conn对象；

3-3 在StudentDao接口中写用到的方法，并在StudentDaoImpl类中实现所有的方法；

3-4 创建servlet包，在StudentServlet中调用所有的StudentDao接口中的方法（目的：方便管理、纠错、隔离）；

3-5 创建主界面、新增学生界面、修改学生界面等三个页面；

3-6 在servlet包下创建类（StudentServletAdd、StudentServletDelete、StudentServletModify），三个类继承 HTTPServlet ，与三个页面结合实现新增、删除、修改等操作；

3-7 没有写登录页面。