ResultSet 的问题!!在线等!菜鸟求救
我的程序是这样的: 
 package   brick0906;   
 import   java.sql.*; 
 import   java.sql.Date; 
 import   java.util.*; 
 import   java.io.*;   
 public   class   ArrayListText   {  	 
 	public   static   String   drivername= "oracle.jdbc.driver.OracleDriver "; 
 	public   Connection   conn=null; 
 	ResultSet   rs=null; 
 	String   classno=null; 
 	String   classname=null; 
 	String   classteacher=null; 
 	//Date   classdate=null;  	 
 	public   static   void   main(String   args   [])   throws   
ClassNotFoundException,   
SQLException,   
IOException{  		 
 		ArrayListText   ar=new   ArrayListText(); 
 		ArrayList   al=new   ArrayList(); 
 		ar.conninit(); 
 		ar.select(); 
 		al.add(ar.classno); 
 		al.add(ar.classname); 
 		al.add(ar.classteacher); 
 		PrintWriter   pw   =new   PrintWriter(new   FileWriter(new   File( "F://java.txt "))); 
 		pw.println(al.get(0)); 
 		pw.println(al.get(1)); 
 		pw.println(al.get(2)); 
 		pw.close(); 
 		ar.connclose();  		 
 	}  	 
 	public   void   conninit()   throws   Class
NotFoundException,   SQLException{ 
 		Class.forName(drivername); 
 		String   url= "jdbc:oracle:thin:@169.254.179.82:1521:brick "; 
 		conn=DriverManager.getConnection(url, "brick ", "brick "); 
 	}  	 
 	public   void   connclose()   throws   SQLException{ 
 		conn.close(); 
 	}  	 
 	public   void   select()   throws   SQLException{ 
 		Statement   ps=null; 
 		String   sql= "select   *   from   classinfo "; 
 		ps=conn.createStatement(); 
 		rs=ps.executeQuery(sql); 
 		while(rs.next()){ 
 		this.classno=rs.getString( "classno "); 
 		this.classname=rs.getString( "classname "); 
 		this.classteacher=rs.getString( "classteacher "); 
 	} 
 	}   
 }   
 这样的话,我只能在java.txt中显示查询的最后一行,但是我要每行都显示.我弄了很久没搞出来,头都大了,各位大哥帮帮
------解决方案--------------------while(rs.next()){ 
   this.classno=rs.getString( "classno "); 
   this.classname=rs.getString( "classname "); 
   this.classteacher=rs.getString( "classteacher "); 
 }   
 你这个当然只能显示最后一行了,若记录集有多条的话,后面的把前的冲掉了,需要更改代码结构。
------解决方案--------------------楼上的强,