JDBC工具类

配置文件

driver=com.mysql.cj.jdbc.Driver
url=jdbc:mysql:///test?useUnicode=true&characterEncoding=utf8&useSSL=true&serverTimezone=UTC
user=root
password=***********//密码

简化后代码

package JDBC;

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

public class jdbctest {
    public static void main(String[] args) {
        Connection conn =null;
        Statement stmt =null;
        ResultSet rs =null;
        try {
            conn = JDBCtool1.getConnection();
            String sql="select * from account";
            stmt = conn.createStatement();
             rs = stmt.executeQuery(sql);
             while(rs.next()){
                 int id = rs.getInt(1);
                 String name = rs.getString("name");
                 double balance = rs.getDouble(3);
                 System.out.println(id+"==="+name+"==="+balance);
             }
        } catch (SQLException e) {
            e.printStackTrace();
        }finally {
            JDBCtool1.close(rs,stmt,conn);
        }

    }
}

工具类

package JDBC;

import com.sun.istack.internal.localization.NullLocalizable;

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

public class jdbcdemo1 {
    public static void main(String[] args){
        Statement sttn =null;
        Connection conn =null;

        try {

            Class.forName("com.mysql.cj.jdbc.Driver");
            String sql="insert into account values(null,'哈哈',3000)";
            conn = DriverManager.getConnection("jdbc:mysql:///test?useUnicode=true&characterEncoding=utf8&useSSL=true&serverTimezone=UTC", "root", "1614553361");

            sttn = conn.createStatement();
            int i = sttn.executeUpdate(sql);
            System.out.println(i);
        } catch (SQLException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } finally {
            if(sttn!= null)
            {
                try {
                    sttn.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            if(conn!= null)
            {
                try {
                   conn.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

欢迎大佬给我斧正