import java.sql.*; public class oracle {      String driver = "oracle.jdbc.OracleDriver";     String url="jdbc:oracle:thin:@localhost:1521:orcl";//@主机名:监听端口:数据库实例名称,Attention notes:the port is generally 1521     String name = "system";//登录名     String pwd = "orcl";//登陆密码          private static Statement sql = null;        private static ResultSet rs = null;     private static Connection con = null;      public Connection getCon()      {         try          {              Class.forName(driver); //注册oracle数据库驱动         }          catch (ClassNotFoundException e1)         {             System.out.println("驱动加载失败!");             e1.printStackTrace();         }         try          {             con = DriverManager.getConnection(url, name, pwd);//获取连接字符串         }          catch (SQLException e)          {             System.out.println("驱动或数据库连接失败！");             e.printStackTrace();         }         return con;     }      public static void main(String[] args)      {    	 try    	 {	         oracle db = new oracle();	         Connection con = db.getCon();	         if (con != null) 	         {	             System.out.println("数据库连接成功！");	         } 	         else 	         {	             System.out.println("数据库连接失败！");	         }	         sql = con.createStatement();         	         rs = sql.executeQuery("select * from students");	         System.out.println("编号\t学号\t姓名\t性别\t出生日期");	         while (rs.next())	         {	        	 System.out.println(rs.getInt(1)+"\t"+rs.getString(2)+"\t"+rs.getString(3)+"\t"+rs.getString(4)+"\t"+rs.getString(5));	         }    	 }    	 catch(Exception e)    	 {    		 e.printStackTrace();            	 }     } }