java连接MySQL数据库操作步骤

package com.swift;
//这里导入的包是java.sql.Connection而不是com.mysql.jdbc.Connection
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;

public class TestJDBC {

public static void main(String[] args) {
        Connection conn=null;
        Statement st=null;
        ResultSet rs=null;
try {
//1、装载驱动
            Class.forName("com.mysql.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
try {
//2、链接数据库，使用com.mysql.jdbc.Connection包会出错
            List<User> list=new ArrayList<User>();
            conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/sw_database?user=root&password=root");
//3、创建连接语句
            st=conn.createStatement();
//4、执行ＳＱＬ语句获得结果集
            rs=st.executeQuery("select * from sw_user");
//5、循环获得数据库字段生成对象
while(rs.next()) {
int id=rs.getInt("id");
                String username=rs.getString("username");
                String password=rs.getString("password");
                User user=new User(id,username,password);
                list.add(user);
            }
//6、遍历对象列表
for(User user:list) {
                System.out.println(user.toString());
            }

        } catch (SQLException e) {
// TODO Auto-generated catch block
            e.printStackTrace();
        }finally {
//7、关闭结果集
try {
if(rs!=null) {
                   rs.close();
                }
            } catch (SQLException e) {
// TODO Auto-generated catch block
                e.printStackTrace();
            }
//7、关闭连接语句
try {
if(st!=null) {
                   st.close();
                }
            } catch (SQLException e) {
// TODO Auto-generated catch block
                e.printStackTrace();
            }
//7、关闭数据库连接
try {
if(conn!=null) {
                    conn.close();
                }
            } catch (SQLException e) {
// TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }

}