使用JDBC连接MySQL数据库并且完成增删改查完整代码

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完整路径截图：

**//BaseDao.java文件**
package cn.utils;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class BaseDao {

    /**
     * 1.四个常量 driver 驱动 url 连接地址 username数据库登录名 password 密码
     */
    private static final String DRIVER = "com.mysql.jdbc.Driver";
    private static final String URL = "jdbc:mysql://127.0.0.1:3306/myschool?characterEncoding=utf-8";
    private static final String USERNAME = "root";
    private static final String PASSWOED = "root";
    // 2.static块加载驱动类
    static {
        try {
            Class.forName(DRIVER);
        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

    // 3.用DriverManager获取数据库连接对象Connection
    public Connection getConnection() throws SQLException {
        return DriverManager.getConnection(URL, USERNAME, PASSWOED);
    }

    // 4.用connection对象获取preparedStatement预编译执行对象
    public PreparedStatement createPreparedStatement(Connection conn,
            String sql, Object... params) throws SQLException {
        PreparedStatement pstmt = conn.prepareStatement(sql);
        if (params != null && params.length > 0) {
            int i = 1;// 标识“？”占位符的位置，默认为1，表示第一个？
            for (Object p : params) {
                pstmt.setObject(i, p);
                i++;
            }
        }
        return pstmt;
    }

    // 5.公用的DML语句执行方法，执行增、删、改，返回影响行数
    public int excuteDML(String sql, Object... params) {
        // 获取Connection连接对象
        Connection conn = null;
        // 获取编译执行对象
        PreparedStatement pstmt = null;
        int result = 0;
        try {
            conn = this.getConnection();
            pstmt = this.createPreparedStatement(conn, sql, params);
            result = pstmt.executeUpdate();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            this.closeAll(conn, pstmt, null);
        }
        return result;
    }

    protected void closeAll(Connection conn, PreparedStatement stmt,
            ResultSet rs) {
        if (rs != null) {
            try {
                rs.close();// 关闭结果集
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } finally {
                // 关闭连接对象和执行对象
                this.closeConnAndPstmt(conn, stmt);

            }
        } else {
            this.closeConnAndPstmt(conn, stmt);
        }
    }

    private void closeConnAndPstmt(Connection conn, PreparedStatement stmt) {
        if (stmt != null) {
            try {
                stmt.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } finally {
                if (conn != null) {
                    try {
                        conn.close();
                    } catch (SQLException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
            }
        }
    }
}
**//StudentServlet.java文件**
package cn.servlet;

import java.util.List;
import java.util.Scanner;

import cn.entit.Student;
import cn.service.StudentService;
import cn.service.impl.StudentServiceImpl;

public class StudentServlet {
    // 定义业务逻辑层接口，指向业务逻辑层实现类
    private static StudentService studentService = new StudentServiceImpl();

    /**
     * 表示控制层：学生表
     * 
     * @param args
     *            作用：传递用户输入的信息，调用后台业务逻辑层代码，实现增删改查
     * 
     */
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        do {
            System.out.println("请选择操作类型：1.添加2.删除3.修改4.查询5.学号查询");
            int choose = input.nextInt();
            switch (choose) {
            case 1:
                addStudent(input);// 添加
                break;
            case 2:
                delStudent(input);// 删除
                break;
            case 3:
                insStudent(input);// 修改
                break;
            case 4:
                selStudent();// 查询
                break;
            case 5:
                // 学号查询
                selectStudentByNo(input);// 查询
                break;
            default:
                System.out.println("无效输入");
                break;
            }
        } while (true);

    }

    private static void selectStudentByNo(Scanner input) {
        System.out.println("请输入您要查询的学号:");
        Integer studentNo = input.nextInt();
        List<Student> students = studentService.selectStudentByNo(studentNo);

        for (Student s : students) {
            System.out.println("学号：" + s.getStudentNo() + "\t姓名"
                    + s.getStudentName() + "\t手机号：" + s.getPhone() + "\t生日"
                    + s.getBornData());
        }
    }

    private static void selStudent() {
        List<Student> students = studentService.selStudent();
        for (Student s : students) {
            System.out.println("学号：" + s.getStudentNo() + "\t姓名"
                    + s.getStudentName() + "\t手机号：" + s.getPhone() + "\t生日"
                    + s.getBornData());
        }
    }

    // 修改
    private static void insStudent(Scanner input) {
        System.out.println("请输入要修改的学号：");
        Integer studentNo = input.nextInt();
        System.out.println("请输入要修改的密码：");
        String loginPwd = input.next();

        Student student = new Student();
        student.setStudentNo(studentNo);
        student.setLoginPwd(loginPwd);

        int result = studentService.insStudent(student);
        if (result > 0) {
            System.out.println("更新成功");
        } else {
            System.out.println("更新失败");

        }
    }

    // 删除
    private static void delStudent(Scanner input) {
        System.out.println("请输入要删除的学号");
        int studentNo = input.nextInt();

        int result = studentService.delStudent(studentNo);
        if (result > 0) {
            System.out.println("删除成功");
        } else {
            System.out.println("删除失败");

        }
    }

    // 添加
    private static void addStudent(Scanner input) {
        // Scanner input = new Scanner(System.in);
        System.out.println("请输入学号：");
        Integer studentNo = input.nextInt();
        System.out.println("请输入登录密码：");
        String loginPwd = input.next();
        System.out.println("请输入学生姓名：");
        String studentName = input.next();
        System.out.println("请输入性别：");
        String sex = input.next();
        System.out.println("请输入年级编号：");
        Integer gradelD = input.nextInt();
        Student student = new Student(studentNo, loginPwd, studentName, sex,
                gradelD);
        // 调用业务逻辑层添加学生信息，获取影响行数
        int result = studentService.addStudeng(student);
        if (result > 0) {
            System.out.println("添加成功");
        } else {
            System.out.println("添加失败");

        }
    }

}
**//StudentService.java文件**
package cn.service;

import java.util.List;

import cn.entit.Student;

public interface StudentService {

    int addStudeng(Student student);

    int delStudent(int studentNo);

    int insStudent(Student student);

    List<Student> selStudent();

    List<Student> selectStudentByNo(Integer studentNo);

}
**//StudentServiceImpl.java文件**
package cn.service.impl;

import java.util.ArrayList;
import java.util.List;

import cn.dao.StudentDao;
import cn.dao.impl.StudengDaoImpl;
import cn.entit.Student;
import cn.service.StudentService;

/**
 * 业务逻辑层实现类：学生表 作用：传递的参数合法性，及业务逻辑分支判断，调用数据访问层实现CRUD
 */
public class StudentServiceImpl implements StudentService {
    // 创建数据访问层接口对象，指向数据访问层实现类
    private StudentDao studentDao = new StudengDaoImpl();

    @Override
    public int addStudeng(Student student) {
        int result = 0;// 影响行数
        if (student != null) {
            if (student.getStudentNo() != null) {
                // 当数据合法时，调用数据访问层，执行CRUD
                result = studentDao.addStudent(student);
            }
        }
        return result;
    }

    @Override
    public int delStudent(int studentNo) {
        int result = 0;// 影响行数
        if (studentNo >= 9999 && studentNo <= 100000) {
            // 当数据合法时，调用数据访问层，执行CRUD
            result = studentDao.delStudent(studentNo);
        }
        return result;
    }

    @Override
    public int insStudent(Student student) {
        int result = 0;// 影响行数
        if (student != null) {
            if (student.getStudentNo() != null) {
                // 当数据合法时，调用数据访问层，执行CRUD
                result = studentDao.insStudent(student);
            }
        }
        return result;
    }

    @Override
    public List<Student> selStudent() {
        return studentDao.selStudent();
    }

    @Override
    public List<Student> selectStudentByNo(Integer studentNo) {
        List<Student> list=new ArrayList<Student>();
        if (studentNo >= 9999 && studentNo <= 100000) {
            // 当数据合法时，调用数据访问层，执行CRUD
            list = studentDao.selectStudentByNo(studentNo);
        }
        return list;
    }

}
**//Student.java文件**
package cn.entit;

import java.util.Date;

/**
 * 学生表实体类
 * 
 * @author Administrator
 * 
 */
public class Student {
    private Integer studentNo;// 学号
    private String loginPwd;// 登录密码
    private String studentName;// 学生姓名
    private String sex;// 性别
    private Integer gradelD;// 年级编号
    private String phone;// 手机号
    private String address;// 地址
    private Date bornData;// 出生日期
    private String email;// 邮箱
    private String identityCard;// 身份证号

    public Student() {
        // TODO Auto-generated constructor stub
    }

    public Student(Integer studentNo, String loginPwd, String studentName,
            String sex, Integer gradelD, String phone, String address,
            Date bornData, String email, String identityCard) {
        super();
        this.studentNo = studentNo;
        this.loginPwd = loginPwd;
        this.studentName = studentName;
        this.sex = sex;
        this.gradelD = gradelD;
        this.phone = phone;
        this.address = address;
        this.bornData = bornData;
        this.email = email;
        this.identityCard = identityCard;
    }

    public Student(Integer studentNo, String loginPwd, String studentName,
            String sex, Integer gradelD) {
        super();
        this.studentNo = studentNo;
        this.loginPwd = loginPwd;
        this.studentName = studentName;
        this.sex = sex;
        this.gradelD = gradelD;
    }

    public Integer getStudentNo() {
        return studentNo;
    }

    public void setStudentNo(Integer studentNo) {
        this.studentNo = studentNo;
    }

    public String getLoginPwd() {
        return loginPwd;
    }

    public void setLoginPwd(String loginPwd) {
        this.loginPwd = loginPwd;
    }

    public String getStudentName() {
        return studentName;
    }

    public void setStudentName(String studentName) {
        this.studentName = studentName;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public Integer getGradelD() {
        return gradelD;
    }

    public void setGradelD(Integer gradelD) {
        this.gradelD = gradelD;
    }

    public String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public Date getBornData() {
        return bornData;
    }

    public void setBornData(Date bornData) {
        this.bornData = bornData;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getIdentityCard() {
        return identityCard;
    }

    public void setIdentityCard(String identityCard) {
        this.identityCard = identityCard;
    }

}
**//StudentDao.java文件**
package cn.dao;

import java.util.List;

import cn.entit.Student;

public interface StudentDao {

    int addStudent(Student student);

    int delStudent(int studentNo);

    int insStudent(Student student);

    List<Student> selStudent();

    List<Student> selectStudentByNo(Integer studentNo);


}
//StudengDaoImpl.java文件
package cn.dao.impl;

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 cn.dao.StudentDao;
import cn.entit.Student;
import cn.utils.BaseDao;

/**
 * 数据访问层实现类：学生表
 * 
 * @author Administrator 作用：调用jdbc连接，执行增删改查方法，实现数据持久化操作
 */
public class StudengDaoImpl extends BaseDao implements StudentDao {
    // 全局的数据库3个对象，连接、执行、结果集
    private Connection conn = null;
    private PreparedStatement pstmt = null;
    private ResultSet rs = null;

    @Override
    public int addStudent(Student student) {
        String sql = "insert into student(studentNo, loginPwd, studentName, sex,gradelD)value (?,?,?,?,?)";
        Object[] params = { student.getStudentNo(), student.getLoginPwd(),
                student.getStudentName(), student.getSex(),
                student.getGradelD() };
        return this.excuteDML(sql, params);
    }

    @Override
    public int delStudent(int studentNo) {
        String sql = "delete from student where studentNo=?";
        Object[] params = { studentNo };
        return this.excuteDML(sql, params);
    }

    @Override
    public int insStudent(Student student) {
        String sql = "update student set loginPwd=? where studentNo=?";
        Object[] params = { student.getLoginPwd(), student.getStudentNo() };
        return this.excuteDML(sql, params);
    }

    @Override
    public List<Student> selStudent() {
        List<Student> list = new ArrayList<Student>();
        try {
            conn = this.getConnection();// 1.获取数据库连接对象
            String sql = "select studentNo,studentName,phone,bornData from student";
            pstmt = this.createPreparedStatement(conn, sql);// 2.获取预编译执行对象
            rs = pstmt.executeQuery();// 3.执行查询语句DQL
            while (rs.next()) {
                Student student = new Student();
                student.setStudentNo(rs.getInt("studentNo"));
                student.setStudentName(rs.getString("studentName"));
                student.setPhone(rs.getString("phone"));
                student.setBornData(rs.getDate("bornData"));
                list.add(student);
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            this.closeAll(conn, pstmt, rs);
        }
        return list;
    }

    @Override
    public List<Student> selectStudentByNo(Integer studentNo) {
        List<Student> list = new ArrayList<Student>();
        try {
            conn = this.getConnection();// 1.获取数据库连接对象
            String sql = "select studentNo,studentName,phone,bornData from student where studentNo=?";
            pstmt = this.createPreparedStatement(conn, sql);// 2.获取预编译执行对象
            pstmt.setInt(1, studentNo);
            rs = pstmt.executeQuery();// 3.执行查询语句DQL
            while (rs.next()) {
                Student student = new Student();
                student.setStudentNo(rs.getInt("studentNo"));
                student.setStudentName(rs.getString("studentName"));
                student.setPhone(rs.getString("phone"));
                student.setBornData(rs.getDate("bornData"));
                list.add(student);
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            this.closeAll(conn, pstmt, rs);
        }
        return list;
    }

}

//数据库student表截图

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