引用:http://iyuan.iteye.com/blog/973013
這裏的發佈與訂閱角色是絕對的,即發佈者無法使用recv,訂閱者不能使用send,並且訂閱者需要設置訂閱條件"setsockopt"。
按照官網的說法,在這種模式下很可能發佈者剛啓動時發佈的數據出現丟失,原因是用zmq發送速度太快,在訂閱者尚未與發佈者建立聯繫時,已經開始了數據發佈(內部局域網沒這麼誇張的)。官網給了兩個解決方案;1,發佈者sleep一會再發送數據(這個被標註成愚蠢的);2,(還沒有看到那,在後續中發現的話會更新這裏)。
上代碼:
發佈端:
package com.zeromq.test.Sync_pub_sub;
import org.zeromq.ZMQ;
import org.zeromq.ZMQ.Context;
import org.zeromq.ZMQ.Socket;
/**
* @author 呂桂強
* @email [email protected]
* @version 創建時間:2012-4-26 下午8:17:40
*/
public class syncpub{
//等待10個訂閱者
protected static int SUBSCRIBERS_EXPECTED = 10;
public static void main (String[] args) {
Context context = ZMQ.context(1);
Socket publisher = context.socket(ZMQ.PUB);
publisher.bind("tcp://*:5561");
try {
//zmq發送速度太快,在訂閱者尚未與發佈者建立聯繫時,已經開始了數據發佈
Thread.sleep (1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
int update_nbr;
for (update_nbr = 0; update_nbr < 10; update_nbr++){
publisher.send("Rhubarb".getBytes(), ZMQ.NOBLOCK);
}
publisher.send("END".getBytes(), 0);
publisher.close();
context.term();
}
}
訂閱者:
package com.zeromq.test.Sync_pub_sub;
import org.zeromq.ZMQ;
import org.zeromq.ZMQ.Context;
import org.zeromq.ZMQ.Socket;
/**
* @author 呂桂強
* @email [email protected]
* @version 創建時間:2012-4-26 下午8:36:42
*/
public class syncsub {
public static void main(String[] args) {
Context context = ZMQ.context(1);
Socket subscriber = context.socket(ZMQ.SUB);
subscriber.connect("tcp://localhost:5561");
subscriber.subscribe("".getBytes());
int update_nbr = 0;
while (true) {
byte[] stringValue = subscriber.recv(0);
String string = new String(stringValue);
if (string.equals("END")) {
break;
}
update_nbr++;
System.out.println("Received " + update_nbr + " updates. :" + string);
}
subscriber.close();
context.term();
}
}