数据库 之JDBC完成英雄排行榜

haohan类

package com.westos.haohan;

public class haohan {

    private int xuhao;
    private String name;

    public void setName(String name) {
        this.name = name;
    }

    public void setXuhao(int xuhao) {
        this.xuhao = xuhao;
    }

    public Integer getXuhao() {
        return xuhao;
    }

    public String getName() {
        return name;
    }

    @Override
    public String toString() {
        return super.toString();
    }
}

haohaninterface接口

package com.westos.haohan;

import java.util.List;

public interface haohaninterface {
    haohan findhaohan(int xuhao);
    List<haohan> listhaohan();
    haohan add(haohan hh);
    haohan update(haohan hh);
    haohan delete(int  xuhao);

}

haohanImpl实现类

package com.westos.haohan;


import java.sql.*;
import java.util.ArrayList;
import java.util.List;

public class haohanImpl implements haohaninterface {



    @Override
    //显示所有好汉
    public List<haohan> listhaohan() {

        //连接数据库
        String driverName="com.mysql.jdbc.Driver";
        String url="jdbc:mysql://localhost:3306/hero?useUnicode=true&characterEncoding=utf-8";
        String username="root";
        String password="123456";

        List<haohan> list=new ArrayList<>();
        haohan hh=new haohan();
        try {
            Class.forName(driverName);
            Connection con = DriverManager.getConnection(url, username, password);

            PreparedStatement ps = con.prepareStatement("select * from heroinfo");
            ResultSet rs = ps.executeQuery();

            while(rs.next()){
                hh.setXuhao(rs.getInt("xuhao"));
                hh.setName(rs.getString("name"));
                list.add(hh);
            }

            //关闭资源
            ps.close();
            con.close();

        } catch (Exception e) {
            e.printStackTrace();
        }

        return list;
    }



    @Override
    //根据序号查询好汉
    public haohan findhaohan(int xh) {

        //连接数据库
        String driverName="com.mysql.jdbc.Driver";
        String url="jdbc:mysql://localhost:3306/hero?useUnicode=true&characterEncoding=utf-8";
        String username="root";
        String password="123456";

        haohan hh=new haohan();
        try {
            Class.forName(driverName);
            Connection con = DriverManager.getConnection(url, username, password);

            PreparedStatement ps = con.prepareStatement("select *from heroinfo where xuhao=?");
            ps.setInt(1,xh);
            ResultSet rs = ps.executeQuery();

            while(rs.next()){
                hh.setXuhao(rs.getInt("xuhao"));
                hh.setName(rs.getString("name"));
            }

            //关闭资源
            ps.close();
            con.close();

        } catch (Exception e) {
            e.printStackTrace();
        }

        return hh;
    }


    @Override
    //添加好汉
    public haohan add(haohan hh) {
        //数据库连接
        String driverName="com.mysql.jdbc.Driver";
        String url="jdbc:mysql://localhost:3306/hero?useUnicode=true&characterEncoding=utf-8";
        String username="root";
        String password="123456";

        try {
            Class.forName(driverName);
            Connection con = DriverManager.getConnection(url, username, password);

            PreparedStatement ps = con.prepareStatement("insert into heroinfo(xuhao,name)values(?,?)");
            ps.setInt(1,hh.getXuhao());
            ps.setString(2,hh.getName());

            int i =ps.executeUpdate();
            System.out.println(i);
            //关闭资源
            ps.close();
            con.close();


        } catch (Exception e) {
            e.printStackTrace();
        }


        return hh;
    }

    @Override
    //修改好汉
    public haohan update(haohan hh) {

        //数据库连接
        String driverName="com.mysql.jdbc.Driver";
        String url="jdbc:mysql://localhost:3306/hero?useUnicode=true&characterEncoding=utf-8";
        String username="root";
        String password="123456";

        try {
            Class.forName(driverName);
            Connection con = DriverManager.getConnection(url, username, password);

            PreparedStatement ps = con.prepareStatement("update heroinfo set name=? where xuhao=?");
            ps.setString(1,hh.getName());
            ps.setInt(2,hh.getXuhao());

            int i=ps.executeUpdate();
            System.out.println(i);
            //关闭资源
            ps.close();
            con.close();

        } catch (Exception e) {
            e.printStackTrace();
        }
        return hh;
    }

    @Override
    //删除好汉
    public haohan delete(int xh) {
        //连接数据库
        String driverName="com.musql.jdbc.Driver";
        String url="jdbc:mysql://localhost:3306/hero?useUnicode=true&characterEncoding=utf-8";
        String username="root";
        String password="123456";

        try {
            Class.forName(driverName);
            Connection con = DriverManager.getConnection(url, username, password);

            PreparedStatement ps = con.prepareStatement("delete from heroinfo where xuhao=?");
            ps.setInt(1,xh);

           int i= ps.executeUpdate();
            System.out.println(i);

            //关闭资源
            ps.close();
            con.close();

        } catch (Exception e) {
            e.printStackTrace();
        }

        //为了更好的用户体验,返回一个信息
        haohan hh=new haohan();
        hh.setXuhao(xh);//这个序号里面的内容已经空了
        return hh;
    }



    //测试
    public static void main(String[]args){
        haohaninterface haohanservice=new haohanImpl();
        haohan hh=new haohan();

//        //测试添加

//        hh.setXuhao(4);
//        hh.setName("宋江kdd");
//       haohan result= haohanservice.add(hh);


        //测试修改
//        hh.setXuhao(1);
//        hh.setName("卢俊义");
//        haohan result=haohanservice.update(hh);


        //测试删除
       // haohan result=haohanservice.delete(2);


        //测试查询
        //haohan result=haohanservice.findhaohan(3);

        //测试显示所有好汉
        List result=haohanservice.listhaohan();
        System.out.println(result);

    }
}