Posted on 2006-04-07 10:31
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JSP
**这是管理user信息的类
文件名为onLineUser.java
欢迎访问javajia家(http://www.javajia.com),由yuking制作。2001.1.1
*/ 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;
}
public boolean deleteUser(String userName) {
users.trimToSize();
if(existUser(userName)){
int currUserIndex=-1;
for(
int i=0;i<users.capacity();i++){
if(userName.equals((String)users.get(i))){
currUserIndex=i;
break;
}
}
if (currUserIndex!=-1){
users.remove(currUserIndex);
users.trimToSize();
return true;
}
}
return false;
}
public Vector getOnLineUser()
{
return users;
}
public void valueBound(HttpSessionBindingEvent e) {
users.trimToSize();
if(!existUser(e.getName())){
users.add(e.getName());
System.out.print(e.getName()+
"\t 登入到系统\t"+(
new Date()));
System.out.println(
" 在线用户数为："+getCount());
}
else System.out.println(e.getName()+
"已经存在");
}
public void valueUnbound(HttpSessionBindingEvent e) {
users.trimToSize();
String userName=e.getName();
deleteUser(userName);
System.out.print(userName+
"\t 退出系统\t"+(
new Date()));
System.out.println(
" 在线用户数为："+getCount());
}
}