java连接数据库基础操作实例代码，备用。

	public static void main(String[] args) {
		try{
			//mysql
			String URL="jdbc:mysql://127.0.0.1:3306/mytest?useSSL=false&useUnicode=true&characterEncoding=utf-8&allowMultiQueries=true";
			//oracle
            //String URL="jdbc:oracle:thin:@127.0.0.1:1521:orcl";
	        String USER="root";
	        String PASSWORD="root";
	        //1.加载驱动
	        //mysql
	        Class.forName("com.mysql.jdbc.Driver");
	        //oracle
            //Class.forName("oracle.jdbc.driver.OracleDriver");
	        //2.获得数据库链接
	        Connection conn=DriverManager.getConnection(URL, USER, PASSWORD);
	        Statement st=conn.createStatement();
	        //3.执行sql语句
	        ResultSet rs=st.executeQuery("select username,phone from t_user");
	        //4.获取返回结果
	        while(rs.next()){
	            System.out.println(rs.getString("username")+":"+rs.getString("phone"));
	        }
	        
	        //关闭数据资源
	        rs.close();
	        st.close();
	        conn.close();
		}catch(Exception e){
			e.printStackTrace();
		}
	}