JDBC连接MySQL操作步骤

package testJDBC;

import java.sql.*;

public class JDBCdemo1 {

public static void main(String[] args){
Connection conn = null;
Statement statement = null;
ResultSet resultSet = null;
//1.注册数据库驱动
try {

    Class.forName("com.Mysql.jdbc.Driver");
    //加载一个类到内存中,该类中有一静态代码块,该代码块中有注册驱动的代码
    //静态代码块伪代码如下：DriverManager.reGISterDriver( new Driver() )

    //2.获取数据库连接
    String url = "jdbc:mysql://localhost:3306/" +
            "jt_db" +
            "?characterEncoding=utf-8";
    

    String user = "root";           //数据库连接用户名
    String passWord = "123456";     //数据库连接密码

   conn = DriverManager.getConnection(url, user, passWord);

    //3.获取传输器

    statement = conn.createStatement();

    

    //4.执行sql语句,返回执行结果

    String sql = "select * from account";
    
    resultSet = statement.executeQuery(sql);

    //5.处理结果
    
    while (resultSet.next()) {
        int id = resultSet.getInt("id");
        String name = resultSet.getString("name");
        double money = resultSet.getDouble("money");
        System.out.println(id + ":" + name + ":" + money);
    }
}catch (Exception e){
    e.printStackTrace();
}finally {

 //6.释放资源
    //越晚获取越先释放！！
    //最好将释放资源代码放在finally里
 if(resultSet!=null) {
     try {
         resultSet.close();
     } catch (SQLException e) {
         e.printStackTrace();
     } finally {
         resultSet = null;
     }
 }
    if(statement!=null) {
        try {
            statement.close();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            statement = null;
        }
    }
    if(conn!=null) {
        try {
            conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            conn = null;
        }
    }

}

}
}