JDBC入门try/catch型

package com.itheima.domain;

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

public class JDBCyh {
	public static void main(String[] args) {
		Connection conn=null;
		Statement stmt=null;
		ResultSet rs=null;
		try{
			//1,加载驱动程序
			Class.forName("com.mysql.jdbc.Driver");
			//2,链接数据库
			conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/qq","root","111111");
			//3,得到发送查询语句的对象
			stmt=conn.createStatement();
			//4,发送语句
			String sql="select id,name,age from user";
			rs=stmt.executeQuery(sql);
			//5,打印
			while(rs.next()){
				System.out.print("id号:"+rs.getInt("id"));
				System.out.print("姓名:"+rs.getString("name"));
				System.out.println("年龄:"+rs.getInt("age"));
			}
		}catch(Exception e){
			e.printStackTrace();
		}finally{
			//6释放资源
			if(rs!=null){
				try {
					rs.close();
				} catch (SQLException e) {
					e.printStackTrace();
				}
				rs=null;
			}
			if(stmt!=null){
				try {
					stmt.close();
				} catch (SQLException e) {
					e.printStackTrace();
				}
				stmt=null;
				
			}
			if(conn!=null){
				try {
					conn.close();
				} catch (SQLException e) {
					e.printStackTrace();
				}
				conn=null;
			}
		}
	}
}