JDBC连接数据库实现——手把手教你打造一款简单的图书管理系统

public class Book {    //定义图书的编号、名称、出版社、价格    private String id,name,press;    private double price;    //构造方法    public Book(String id, String name, String press, double price) {        this.id = id;        this.name = name;        this.press = press;        this.price = price;}    public String getId() {        return id;}    public void setId(String id) {        this.id = id;}    public String getName() {        return name;}    public void setName(String name) {        this.name = name;}    public String getPress() {        return press;}    public void setPress(String press) {        this.press = press;}    public double getPrice() {        return price;}    public void setPrice(double price) {        this.price = price;  }}

import java.sql.*;import java.util.Scanner;public class BookManager {    //定义com.mysql.jdbc的Driver类路径、数据库的地址、用户名、密码    static String driver ="com.mysql.jdbc.Driver";    static String url="jdbc:mysql://localhost:3306/book?useUnicode=true&characterEncoding=utf-8";    static String user="root";    static String pwd="168168";    //创建Connection、Statement、ResultSet对象    static Connection con;    static Statement stmt;    static ResultSet rs;    public static void main(String[] args) {        BookManager bm=new BookManager();        try {            Class.forName(driver);//加载驱动程序            System.out.println("加载驱动成功！");            con=DriverManager.getConnection(url,user,pwd);            stmt=con.createStatement();        } catch (ClassNotFoundException e) {            e.printStackTrace();        } catch (SQLException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }        //模块化        System.out.println("1---插入图书");        System.out.println("2---删除图书");        System.out.println("3---更新图书信息");        System.out.println("4---查询图书信息");        System.out.println("请输入你的选择1~4：");        Scanner sc=new Scanner(System.in);        int i=sc.nextInt();        switch(i){        case 1:            insertBook();break;        case 2:            deleteBook();break;        case 3:            updateBook();break;        case 4:            queryBook();break;        default:            System.out.println("您的输入有误！");        }}    private static void queryBook(){//查询        String sql="select * from book";        try {            rs=stmt.executeQuery(sql);            while(rs.next()){                System.out.println(rs.getString("id"));                System.out.println(rs.getString("name"));                System.out.println(rs.getString("press"));                System.out.println(rs.getDouble("price"));            }        } catch (SQLException e) {            e.printStackTrace();        }}    private static void updateBook(){//修改        System.out.println("请输入图书Id：");        Scanner sc=new Scanner(System.in);        String oldid=sc.next();        System.out.println("请输入您要更新图书Id：");        String newid=sc.next();        String sql="update book set id='"+newid+"' where id='"+oldid+"'";        try {            stmt.executeUpdate(sql);        } catch (SQLException e) {            e.printStackTrace();        }        System.out.println(sql);}    private static void deleteBook(){//删除        System.out.println("请输入您要删除的图书Id：");        Scanner sc=new Scanner(System.in);        String id=sc.next();        String sql="delete from book where id='"+id+"'";        System.out.println(sql);        try {            stmt.executeUpdate(sql);        } catch (SQLException e) {            e.printStackTrace();        }}    private static void insertBook(){//插入        Scanner sc=new Scanner(System.in);        System.out.println("请输入您要添加的图书id：");        String id=sc.next();        System.out.println("请输入您要添加的图书name：");        String name=sc.next();        System.out.println("请输入您要添加的图书press：");        String press=sc.next();        System.out.println("请输入您要添加的图书price：");        String price=sc.next();        try {            Book b=new Book(id,name,press,Integer.valueOf(price));            String sql="insert into book values('"+b.getId()+"','"+b.getName()+"','"+b.getPress()+"',"+b.getPrice()+")";            System.out.println(sql);            stmt.executeUpdate(sql);        } catch (SQLException e) {            e.printStackTrace();        }    }}