mysql数据库如何实现与Java项目连接

package com.shaocoder.connection;

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

public class ConnectionTest {
	public static void main(String[] args) {
		Connection conn = null;
		try {
			//1.数据库连接的4个基本要素
			//①JDBC URL用于标识一个被注册的驱动程序，驱动程序管理器通过这个URL选择正确的驱动程序，从而建立到数据库的连接；
			//jdbc：表示URL中的协议
			//mysql：子协议，用于标识mysql数据库驱动程序
			//localhost:本机的IP地址
			//3306：端口号
			//test：表示访问test数据库
			String url = "jdbc:mysql://localhost:3306/test";
			//user:登录数据库的用户名
			String user = "root";
			//password:用户名对应的密码，这些都是自己之前设定的
			String password = "123456";
			//mySql的驱动：com.mysql.jdbc.Driver
			String driverName = "com.mysql.jdbc.Driver";
			
			//2.实例化Driver
			Class clazz = Class.forName(driverName);
			Driver driver = (Driver) clazz.newInstance();
			
			//3.通过DriverManager来注册驱动
			DriverManager.registerDriver(driver);
			//4.通过DriverManager的getConnection方法，获取Connection类的对象
			conn = DriverManager.getConnection(url, user, password);
			//5.打印出conn对象
			System.out.println(conn);
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			try {
				//当conn不为空时
				if(conn != null) 
					//关闭conn资源
					conn.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	}
}

package com.shaocoder.connection;

import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Properties;

public class ConnectionTest {

	public static void main(String args[]) {
		InputStream is = null;
		Connection conn = null;
		try {
			//通过类加载器访问jdbc.properties文件，转化为输入流
			is = ClassLoader.getSystemClassLoader().getResourceAsStream("jdbc.properties");
			Properties pros = new Properties();
			pros.load(is);
			
			String user = pros.getProperty("user");
			String password = pros.getProperty("password");
			String url = pros.getProperty("url");
			String driverClass = pros.getProperty("driverClass");
			
			Class.forName(driverClass);
			
			conn = DriverManager.getConnection(url, user, password);
			
			System.out.println(conn);
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			
			try {
				if(conn != null)
					conn.close();
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
			try {
				if(is != null)
					is.close();
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
				
		}
		
	}
}