java连接MYSQL，对数据库进行操作
DBUtil.java
package Stu;
import java.sql.*;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.lang.Exception;
import java.sql.Statement;
public class DBUtil {
private static final String DRIVER_NAME = "com.mysql.jdbc.Driver";
private static final String URL = "jdbc:mysql://localhost:3306/test";
private static final String USER = "root";
private static final String PASS = "123456";
public static Connection getCon() throws ClassNotFoundException,SQLException {
Connection con = null;
Class.forName(DRIVER_NAME);
con = DriverManager.getConnection(URL, USER, PASS);
return con;
}
public static void close(Connection con, Statement stmt, ResultSet rs) {
try {
if (rs != null) {
rs.close();
}
if (stmt != null) {
stmt.close();
}
if (con != null) {
con.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
/* StuManage s=new StuManage();
s.menu();*/
}
}
Main.java
package Stu;
//主函数测试类
public class Main {
/**
* @paramargs
*/
public static void main(String[] args) {
StuManage s=new StuManage();
s.menu();
}
}
Stu.java
package Stu;
//实体类，封装学生类数据
/**
* @authorScatlett
*/
public class Stu {
private String no; //学号
private String name; //姓名
private String phone; //手机号
//getter setter
public String getNo() {
return no;
}
public void setNo(String no) {
this.no = no;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPhone() {
return phone;
}
public void setPhone(String phone) {
this.phone = phone;
}
//无参构造函数
public Stu() {
super();
// TODO Auto-generated constructor stub
}
//有参构造函数
public Stu(String no, String name, String phone) {
super();
this.no = no;
this.name = name;
this.phone = phone;
}
}
StuManage.java
package Stu;
//学生信息管理系统的菜单选择
import java.sql.Connection;
import java.util.List;
import java.util.Scanner;
import javax.print.DocFlavor.INPUT_STREAM;
//import org.omg.CORBA.PUBLIC_MEMBER;
import studao.StuDao;
public class StuManage{
public void menu() {
//1.打印菜单
//2.输入菜单
//3.switch菜单选择
int choose;
do {
System.out.println("******************************");
System.out.println("=======欢迎进入学生信息管理系统=======");
System.out.println("1.新增学生");
System.out.println("2.修改学生");
System.out.println("3.删除学生");
System.out.println("4.查询学生");
System.out.println("5.退出该系统");
System.out.println("请选择（1-5）：");
Scanner scanner=new Scanner(System.in);
choose=scanner.nextInt();
System.out.println("******************************");
switch (choose) {
case 1:
myAdd(); //菜单选择1，是新增学生
break;
case 2:
myUpdate(); //菜单选择2，是修改学生
break;
case 3:
myDel(); //菜单选择3，是删除学生
break;
case 4:
myList(); //菜单选择4，是查询学生
break;
case 5: //菜单选择5，是退出该系统
System.out.println("您选择了退出系统，确定要退出吗？(y/n)");
Scanner scan=new Scanner(System.in);
String scanExit=scan.next();
if(scanExit.equals("y")){
System.exit(-1);
System.out.println("您已成功退出系统，欢迎您再次使用！");
}
break;
default:
break;
}
} while (choose!=5);
}
//新增学生信息
public void myAdd() {
String continute;
do {
Scanner s=new Scanner(System.in);
String no,name,phone;
System.out.println("====新增学生====");
System.out.println("学号：");
no=s.next();
System.out.println("姓名：");
name=s.next();
System.out.println("手机号：");
phone=s.next();
Stu stu=new Stu(no,name,phone);
StuDao dao=new StuDao();
boolean ok=dao.add(stu);
if (ok) {
System.out.println("保存成功！");
}else {
System.out.println("保存失败！");
}
System.out.println("是否继续添加(y/n)：");
Scanner scanner2=new Scanner(System.in);
continute=scanner2.next();
} while (continute.equals("y"));
}
//删除学生信息
public void myDel(){
Scanner s=new Scanner(System.in);
String no;
System.out.println("====删除学生====");
System.out.println("请输入要删除的学生学号：");
no=s.next();
System.out.println("该学生的信息如下：");
StuDao stuDao=new StuDao();
System.out.println("学生学号："+stuDao.findSomeone(no).getNo());
System.out.println("学生姓名："+stuDao.findSomeone(no).getName());
System.out.println("学生手机号："+stuDao.findSomeone(no).getPhone());
System.out.println("是否真的删除(y/n)：");
Scanner scanner3=new Scanner(System.in);
String x=scanner3.next();
if (x.equals("y")) {
Stu stu=new Stu(no,null,null);
StuDao dao=new StuDao();
boolean ok=dao.del(no);
if (ok) {
System.out.println("删除成功！");
}else {
System.out.println("删除失败！");
}
}
}
//修改学生信息
public void myUpdate(){
Scanner s=new Scanner(System.in);
String no;
System.out.println("====修改学生====");
System.out.println("请输入要修改的学生学号：");
no=s.next();
System.out.println("该学生的信息如下：");
StuDao stuDao=new StuDao();
System.out.println("学生学号："+stuDao.findSomeone(no).getNo());
System.out.println("学生姓名："+stuDao.findSomeone(no).getName());
System.out.println("学生手机号："+stuDao.findSomeone(no).getPhone());
System.out.println("请输入新的学生信息：");
Scanner stuUp=new Scanner(System.in);
String name,phone;
System.out.println("学生姓名：");
name=stuUp.next();
System.out.println("学生手机号：");
phone=stuUp.next();
Stu stu=new Stu(no,name,phone);
StuDao dao=new StuDao();
boolean ok=dao.update(stu);
if (ok) {
System.out.println("保存成功！");
}else {
System.out.println("保存失败！");
}
}
//查询学生信息
public void myList(){
System.out.println("************************");
System.out.println("====查询学生====");
System.out.println("该学生的信息如下：");
System.out.println("学号\t姓名\t手机号");
StuDao stuDao=new StuDao();
List
for (Stu stuList:list) { //循环打印出查询结果
System.out.println(stuList.getNo()+"\t"+stuList.getName()+"\t"+stuList.getPhone());
}
System.out.println("************************");
}
}
StuDao.java
package studao;
//学生管理数据访问对象StuDao
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 Stu.DBUtil;
import Stu.Stu;
public class StuDao {
private Connection con;
private PreparedStatement pstmt;
private ResultSet rs;
//添加学生信息
public boolean add(Stu stu) {
String sql="insert into stu(stu_no,stu_name,phone) values(?,?,?)";
try {
con=DBUtil.getCon();
pstmt=con.prepareStatement(sql);
pstmt.setString(1, stu.getNo());
pstmt.setString(2, stu.getName());
pstmt.setString(3, stu.getPhone());
pstmt.executeUpdate();
} catch (ClassNotFoundException e) {
e.printStackTrace();
return false;
} catch (SQLException e) {
e.printStackTrace();
return false;
} finally{
DBUtil.close(con, pstmt, rs);
}
return true;
}
//查看学生列表（1所有）
public List
List
String sql="select * from stu";
try {
con=DBUtil.getCon();
pstmt=con.prepareStatement(sql);
//pstmt.executeUpdate();//用于增删改
rs=pstmt.executeQuery();//用于查询
while (rs.next()) {
//Stustu=new Stu(rs.getString("stu_no"),rs.getString("stu_name"),rs.getString("phone"));
//上行写法亦可为：
Stu stu=new Stu();
stu.setNo(rs.getString("stu_no"));//取结果集里面学号这一列的值赋给
stu.setName(rs.getString("stu_name"));
stu.setPhone(rs.getString("phone"));
list.add(stu);
}
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
} finally{
DBUtil.close(con, pstmt, rs);
}
return list;
}
//查看学生列表（2根据学生学号显示学生信息）
public Stu findSomeone(String no) {
Stu stu=null;
String sql="select * from stu where stu_no=?";
try {
con=DBUtil.getCon();
pstmt=con.prepareStatement(sql);
//pstmt.executeUpdate();//用于增删改
pstmt.setString(1,no);
rs=pstmt.executeQuery();//用于查询
while (rs.next()) {
//Stustu=new Stu(rs.getString("stu_no"),rs.getString("stu_name"),rs.getString("phone"));
//上行写法亦可为：
stu=new Stu();
stu.setNo(rs.getString("stu_no"));//取结果集里面学号这一列的值赋给
stu.setName(rs.getString("stu_name"));
stu.setPhone(rs.getString("phone"));
}
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
} finally{
DBUtil.close(con, pstmt, rs);
}
return stu;
}
//修改学生信息
public boolean update(Stu stu) {
String sql="update stu set stu_name=?,phone=? wherestu_no=?";
try {
con=DBUtil.getCon();
pstmt=con.prepareStatement(sql);
pstmt.setString(3, stu.getNo());
pstmt.setString(1, stu.getName());
pstmt.setString(2, stu.getPhone());
pstmt.executeUpdate();
} catch (ClassNotFoundException e) {
e.printStackTrace();
return false;
} catch (SQLException e) {
e.printStackTrace();
return false;
} finally{
DBUtil.close(con, pstmt, rs);
}
return true;
}
//删除学生信息
public boolean del(String id) {
String sql="delete from stu where stu_no=?";
try {
con=DBUtil.getCon();
pstmt=con.prepareStatement(sql);
pstmt.setString(1,id);
pstmt.executeUpdate();
} catch (ClassNotFoundException e) {
e.printStackTrace();
return false;
} catch (SQLException e) {
e.printStackTrace();
return false;
} finally{
DBUtil.close(con, pstmt, rs);
}
return true;
}
}