Java-jdbc-封装类形式的数据库操作

1、建立数据库连接的类

package cn.bruce.MySql;

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

public class Conutils {
    //创建数据库连接的工具类
    private static Connection con=null;
    static
    {
        String usename = "root";
        String password = "jinqi1986";
        String url = "jdbc:mysql://localhost:3306/mytrain?useSSL=false&serverTimezone=CTT";
        String jdbc = "com.mysql.cj.jdbc.Driver";
        try
        {
            Class.forName(jdbc);
            con = DriverManager.getConnection(url, usename, password);
        } catch (Exception e)
        {
            throw new RuntimeException(e + "数据库连接失败！");
        }
    }

    public static Connection recon() {
        return con;
    }
    //创建数据库关闭的工具类(查询）
    public static void close(Connection con,Statement st,ResultSet rs){
        if (rs!=null)
        {
            try
            {
                rs.close();
            } catch (SQLException e)
            {
                e.printStackTrace();
            }
        }
        if (st!=null)
        {
            try
            {
                st.close();
            } catch (SQLException e)
            {
                e.printStackTrace();
            }
        }
        if (con!=null)
        {
            try
            {
                con.close();
            } catch (SQLException e)
            {
                e.printStackTrace();
            }
        }
        }
        //创建数据库关闭的工具类(非查询）
        public static void close(Connection con,Statement st){

            if (st!=null)
            {
                try
                {
                    st.close();
                } catch (SQLException e)
                {
                    e.printStackTrace();
                }
            }
            if (con!=null)
            {
                try
                {
                    con.close();
                } catch (SQLException e)
                {
                    e.printStackTrace();
                }
            }
    }
}

2、建立存放集合的封装类

package cn.bruce.MySql;

public class sort {
    private int zid;
    private String zname;
    private double zprice;
    private String zdesc;

    // 有参构造器
    public sort(int zid, String zname, double zprice, String zdesc)
    {// 依照数据库里的表字段类型创建
        this.zid = zid;
        this.zname = zname;
        this.zprice = zprice;
        this.zdesc = zdesc;
    }

    // 无参构造器
    public sort()
    {

    }

    // get/set方法
    public int getZid() {
        return zid;
    }

    public void setZid(int zid) {
        this.zid = zid;
    }

    public String getZname() {
        return zname;
    }

    public void setZname(String zname) {
        this.zname = zname;
    }

    public double getZprice() {
        return zprice;
    }

    public void setZprice(double zprice) {
        this.zprice = zprice;
    }

    public String getZdesc() {
        return zdesc;
    }

    public void setZdesc(String zdesc) {
        this.zdesc = zdesc;
    }

    // 重写toString
    public String toString() {
        return "sort [zid=" + zid + ", zname=" + zname + ", zprice=" + zprice + ", zdesc=" + zdesc + "]";
    }

}

3、建立main类

package cn.bruce.MySql;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;

public class useutli {
    public static void main(String[] args) throws Exception {

        // 调用数据库连接的工具类
        Connection connection = Conutils.recon();
        String sql = "select * from test;";
        PreparedStatement ps = connection.prepareStatement(sql);
        ResultSet rs = ps.executeQuery();
        // 建立泛型-sort类型list集合
        List<sort> list = new ArrayList<sort>();
        while (rs.next())
        {
            sort s = new sort(rs.getInt("zid"), rs.getString("zname"), rs.getDouble("zprice"), rs.getString("zdesc"));
            list.add(s);
        }
        Conutils.close(connection, ps, rs);
        // 遍历 list
        for (sort s : list)
        {
            System.out.println(s);
        }
    }
}