usrcontainer.java~3~

java编写的聊天室服务器程序

package chatServer;
import chatServer.*;
public class UsrContainer {
    private UserInfo usrList[];
    private int usrNum;
    public UsrContainer()
    {
        usrList=new UserInfo[20];
        usrNum=0;
    }
    public boolean addUser(UserInfo usr)
    {
        int i=0;
        if(usrNum<20)
        {
            for (i = 0;i<usrNum;i++)
           {
               if(usrList[i]==usr)//对象数组中存的是对象的引用，可以直接比较
               {
                   return false;//already exist
               }

           }

            usrList[usrNum]=usr;
            usrNum++;
            return true;
        }
        else return false;
    }
    public boolean delUser(UserInfo usr)
   {
       if(usrNum==0)
           return false;
       else
       {
           int i = 0,j=0,exist=0;
           for (i = 0;i<usrNum;i++)
           {
               if(usrList[i]==usr)//exist
               {
                   j=i;
                   exist=1;
                   break;
               }
           }
           if(exist==1)
           {
                  for (i = j;i<usrNum-1;i++)
              {
                    usrList[i]=usrList[i+1];
              }
              usrNum--;
              return true;
           }
       }
       return false;
   }


}