import?java.net.DatagramPacket;
import?java.net.InetAddress;
import?java.net.MulticastSocket;

//通過接收多播消息獲取多播組的用戶IP列表
public?class?BroadcastIP_rece_Thread?extends?Thread?{
	public?M_system?system;
	boolean?userState;
	int?time=0;

	public?BroadcastIP_rece_Thread（M_system?system）?{
		this.system?=?system;
	}

	@SuppressWarnings（{?“unchecked“?“resource“?}）
	public?void?run（）?{
		try?{
			MulticastSocket?multicastSocket?=?new?MulticastSocket（7777）;
			InetAddress?inetAddress?=?InetAddress.getByName（M_system.broadcastIP）;
			multicastSocket.joinGroup（inetAddress）;
			byte[]?receive_Ip_User?=?new?byte[200];
			system.getAddress（）;
			while?（true）?{
				//?接收到的數據報包也包含發送方的?IP地址和用戶名
				DatagramPacket?datagramPacket?=?new?DatagramPacket（receive_Ip_User?receive_Ip_User.length?inetAddress
						7777）;
				multicastSocket.receive（datagramPacket）;

				String?ip_user?=?new?String（datagramPacket.getData（）?0?datagramPacket.getLength（）?“UTF-8“）;?//?提取為String

				if?（ip_user.charAt（0）?==?‘F‘）?{
					userState=false;
					ip_user?=?ip_user.substring（1）;
					if?（（system.clients.contains（ip_user）））?{
						system.clients.remove（ip_user）;
						system.showUserState（ip_useruserState）;?//?提示用戶下線
					}
				}
				else?if?（!system.clients.contains（ip_user））?{
					system.clients.add（ip_user）;
					userState=true;
					system.showUserState（ip_useruserState）;?//?提示新用戶上線
				}
				
				//每隔一段時間刷新一次列表				
				if?（time>100||time==0）?{					
					system.List_repaint（）;
					time=0;
				}
				time++;
				
				sleep（5）;?//線程休眠5ms
			}
		}?catch?（Exception?exception）?{
			exception.printStackTrace（）;
		}
	}
}

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件????????301??2012-06-24?14:41??Chatp2p_2.7\.classpath

?????文件????????379??2012-06-24?14:41??Chatp2p_2.7\.project

?????文件????????108??2012-06-24?18:14??Chatp2p_2.7\.settings\org.eclipse.core.resources.prefs

?????文件????????629??2012-06-24?14:41??Chatp2p_2.7\.settings\org.eclipse.jdt.core.prefs

?????文件???????2100??2018-12-28?12:57??Chatp2p_2.7\bin\BroadcastIP_rece_Thread.class

?????文件????????959??2018-12-28?13:18??Chatp2p_2.7\bin\BroadcastIP_Thread$1.class

?????文件???????2164??2018-12-28?13:18??Chatp2p_2.7\bin\BroadcastIP_Thread.class

?????文件???????5561??2018-12-28?12:34??Chatp2p_2.7\bin\Main_window.class

?????文件????????441??2018-12-28?12:34??Chatp2p_2.7\bin\Multicast_Chat_Launcher.class

?????文件???????1909??2018-12-28?12:34??Chatp2p_2.7\bin\Multicast_Thread.class

?????文件????????977??2018-12-28?13:23??Chatp2p_2.7\bin\M_system$1.class

?????文件???????9051??2018-12-28?13:23??Chatp2p_2.7\bin\M_system.class

?????文件???????1682??2018-12-28?12:34??Chatp2p_2.7\bin\pMsg_window.class

?????文件???????1741??2018-12-28?12:34??Chatp2p_2.7\bin\Receive_privatemsg.class

?????文件???????2042??2018-12-28?12:39??Chatp2p_2.7\bin\Receive_Thread.class

?????文件???????2016??2018-12-28?12:34??Chatp2p_2.7\bin\Set_window.class

?????文件???????1814??2018-12-28?12:57??Chatp2p_2.7\src\BroadcastIP_rece_Thread.java

?????文件???????1562??2018-12-28?13:18??Chatp2p_2.7\src\BroadcastIP_Thread.java

?????文件???????7159??2018-12-28?11:38??Chatp2p_2.7\src\Main_window.java

?????文件????????114??2018-12-25?19:56??Chatp2p_2.7\src\Multicast_Chat_Launcher.java

?????文件???????1169??2018-12-27?21:44??Chatp2p_2.7\src\Multicast_Thread.java

?????文件??????10001??2018-12-28?13:23??Chatp2p_2.7\src\M_system.java

?????文件???????2120??2018-12-28?09:59??Chatp2p_2.7\src\pMsg_window.java

?????文件????????921??2018-12-28?09:36??Chatp2p_2.7\src\Receive_privatemsg.java

?????文件???????1257??2018-12-28?12:39??Chatp2p_2.7\src\Receive_Thread.java

?????文件???????2070??2018-12-27?16:04??Chatp2p_2.7\src\Set_window.java

?????目錄??????????0??2018-12-28?13:24??Chatp2p_2.7\.settings

?????目錄??????????0??2018-12-28?13:24??Chatp2p_2.7\bin

?????目錄??????????0??2018-12-28?13:24??Chatp2p_2.7\src

?????目錄??????????0??2018-12-28?13:24??Chatp2p_2.7

............此處省略3個文件信息