jsp统计在线人数.txt

JSP应用实例：统计当前在线人数<转帖>
/**这是管理user信息的类 

文件名为onLineUser.java 

*/ 
import javax.servlet.http.*; 
import javax.servlet.*; 
import java.util.*; 
public class onLineUser implements HttpSessionBindingListener { 
public onLineUser(){ 
} 
private Vector users=new Vector(); 
public int getCount(){ 
users.trimToSize(); 
return users.capacity(); 
} 
public boolean existUser(String userName){ 
users.trimToSize(); 
boolean existUser=false; 
for (int i=0;i<users.capacity();i++ ) 
{ 
if (userName.equals((String)users.get(i))) 
{ 
existUser=true; 
break; 
} 
} 
return existUser; 
}