List类型的遍历取值重复

数据存储类：
public class UserList
{
public UserList(String name, String ipEndPoint,String imgIPEndPoint)
{
username = name;
userIPEndPoint = ipEndPoint;
IMGIPEndPoint = imgIPEndPoint;
}
public static String username;
public static String userIPEndPoint;
public static String IMGIPEndPoint;
}
public static List<UserList> users=new ArrayList<UserList>();//值已经赋值好
遍历
public Map SetUserInfo(String user)
{
Map map = new HashMap();
for (UserList m : users)
{
UserList n=(UserList)m;
if(user.equals(n.username))//这里的n有值，但是username一直是第一个遍历的userlist里的值，求解？
{
String[] splitstring=n.IMGIPEndPoint.split(":");
map.put("ip",splitstring[0] );
map.put("port", Integer.parseInt(splitstring[1]));
break;
}
}
return map;
}