提取码: 7sm3
直接放上代码 ·
知识储备：java、mysql、Servlet、HTML、Jquery、Jscript、
我的个人制作过程大概如下：
数据库的创建——数据库的连接——Dao层——Service层——Servlet程序——页面设计。
思路：首先我们要有被管理的对象——Student。那么我们首先要创建Student数据库表。
与此同时创建Student类。
package com.atchensong.pojo;
public class Student {
private Integer id;
private String username;
private int age;
private String gender;
private double score;
public Student() {
}
public Student(Integer id, String username, int age, String gender, double score) {
this.id = id;
this.username = username;
this.age = age;
this.gender = gender;
this.score = score;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
public double getScore() {
return score;
}
public void setScore(double score) {
this.score = score;
}
@Override
public String toString() {
return "Student{" +
"id=" + id +
", username='" + username + ''' +
", age=" + age +
", gender='" + gender + ''' +
", score=" + score +
'}';
}
}
接下来通过JdbcUtils尝试与数据库连接，并查找数据库中的数据。
配置文件-jdbc.properties
driver=com.mysql.jdbc.Driver url=jdbc:mysql://localhost:3306/stu_info?characterEncoding=utf8 username=root password=111111 initialSize=5 maxActive=10
JdbcUtils
package com.atchensong.utils;
import java.io.IOException;
import java.io.InputStream;
import java.sql.*;
import java.util.Properties;
public class JdbcUtils {
private static String driver = null;
private static String url = null;
private static String username = null;
private static String password = null;
static {
try {
InputStream inputStream = JdbcUtils.class.getClassLoader().getResourceAsStream("jdbc.properties");
Properties properties = new Properties();
properties.load(inputStream);
driver = properties.getProperty("driver");
url = properties.getProperty("url");
username = properties.getProperty("username");
password = properties.getProperty("password");
//1.驱动需要加载一次
Class.forName(driver);
} catch (IOException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
//2.获取连接
public static Connection getConnection() throws SQLException {
return DriverManager.getConnection(url, username, password);
}
//3.释放连接
public static void release(Connection connection, Statement statement, ResultSet resultSet) {
if (resultSet != null) {
try {
resultSet.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (statement != null)
try {
statement.close();
} catch (SQLException e) {
e.printStackTrace();
}
if (resultSet != null)
try {
connection.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
确保连接好之后，我们接下来进入页面层面。首先应该实现登录功能。那么登录功能是管理员来登录的，所以应该用管理员的账号与密码。那么在数据库中创建manager表。只需要给上用户名和密码就可以了。
与此同时创建Manager类。
package com.atchensong.pojo;
public class Manager {
private String username;
private String password;
public Manager() {
}
public Manager(String username, String password) {
this.username = username;
this.password = password;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
@Override
public String toString() {
return "Manager{" +
"username='" + username + ''' +
", password='" + password + ''' +
'}';
}
}
编写Dao层实现java程序与数据库的数据交互。
首先创建BaseDao。实现与数据库交互最底层的功能。这段儿代码也可以当作一个模板，适用于其他项目的编写。
package com.atchensong.dao.impl;
import com.atchensong.utils.JdbcUtils;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.apache.commons.dbutils.handlers.ScalarHandler;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.List;
public abstract class BaseDao {
//使用DbUtils操作数据库
private QueryRunner queryRunner = new QueryRunner();
public int update(String sql, Object... args) {
Connection connection = null;
try {
connection = JdbcUtils.getConnection();
return queryRunner.update(connection, sql, args);
} catch (SQLException e) {
e.printStackTrace();
} finally {
JdbcUtils.release(connection, null, null);
}
return -1;
}
public T queryForOne(Class type, String sql, Object... args) {
Connection connection = null;
try {
connection = JdbcUtils.getConnection();
return queryRunner.query(connection, sql, new BeanHandler(type), args);
} catch (SQLException e) {
e.printStackTrace();
} finally {
JdbcUtils.release(connection, null, null);
}
return null;
}
public List queryForList(Class type, String sql, Object... args) {
Connection conn = null;
try {
conn = JdbcUtils.getConnection();
return queryRunner.query(conn, sql, new BeanListHandler(type), args);
} catch (SQLException e) {
e.printStackTrace();
} finally {
JdbcUtils.release(conn, null, null);
}
return null;
}
public Object queryForSingleValue(String sql, Object... args) {
Connection connection = null;
try {
connection = JdbcUtils.getConnection();
return queryRunner.query(connection, sql, new ScalarHandler(), args);
} catch (SQLException e) {
e.printStackTrace();
}
return null;
}
}
创建ManagerDao接口
package com.atchensong.dao;
import com.atchensong.pojo.Manager;
public interface ManagerDao {
public Manager queryUserByUsernameAndPassword(String username, String password);
}
创建Manager实现类。
package com.atchensong.dao.impl;
import com.atchensong.dao.ManagerDao;
import com.atchensong.pojo.Manager;
public class ManagerDaoImpl extends BaseDao implements ManagerDao {
@Override
public Manager queryUserByUsernameAndPassword(String username, String password) {
String sql = "select * from `manager` where username=? and password = ?";
return queryForOne(Manager.class, sql, username, password);
}
}
创建Service层：
package com.atchensong.service;
import com.atchensong.pojo.Manager;
public interface ManagerService {
public Manager login(Manager manager);
}
package com.atchensong.service.impl;
import com.atchensong.dao.ManagerDao;
import com.atchensong.dao.impl.ManagerDaoImpl;
import com.atchensong.pojo.Manager;
import com.atchensong.service.ManagerService;
public class ManagerServiceImpl implements ManagerService {
ManagerDao managerDao = new ManagerDaoImpl();
@Override
public Manager login(Manager manager) {
return managerDao.queryUserByUsernameAndPassword(manager.getUsername(), manager.getPassword());
}
}
确保能够成功运行以后，我们开始实现页面与java程序的交互。这时要用到Servlet知识。
创建实现登录功能的Servlet代码
package com.atchensong.web;
import com.atchensong.pojo.Manager;
import com.atchensong.service.ManagerService;
import com.atchensong.service.impl.ManagerServiceImpl;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
public class LoginServlet extends HttpServlet {
ManagerService managerService = new ManagerServiceImpl();
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
String username = req.getParameter("username");
String password = req.getParameter("password");
Manager login = managerService.login(new Manager(username, password));
if (login == null) {
req.setAttribute("msg", "用户名或密码输入错误");
req.setAttribute("username", username);
req.getRequestDispatcher("/index.jsp").forward(req, resp);
System.out.println("登录失败");
} else {
System.out.println("登录成功");
req.getRequestDispatcher("/login_success.jsp").forward(req, resp);
}
}
}
顺便附上登录页面
<%--
Created by IntelliJ IDEA.
User: 张宸菘
Date: 2022/5/3
Time: 15:59
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%----%>
管理员登录
学 生 管 理 系 统
${ empty requestScope.msg ? "请输入用户名和密码:" :requestScope.msg}
还没有完。在web.xml中配置servlet程序地址。
完成上述工作以后，启动Tomcat，尝试登录操作。
之后的：增删改查操作同登录操作一样：先在Dao层实现与数据库的连接，并编写对应 的方法，在通过Service层调用Dao层的方法。之后编写Servlet程序，配置Servlet程序。
