JGroups: send(null, null, Message)vs send(Address, null, Message)

问题

I've written simple test for using JGroups. There are two simple applications like this

import org.jgroups.*;
import org.jgroups.conf.ConfiguratorFactory;
import org.jgroups.conf.ProtocolConfiguration;
import org.jgroups.conf.ProtocolStackConfigurator;

import java.util.List;

/**
 * @author Sergii.Zagriichuk
 */
public class Test {
    public static void main(String[] args) throws Exception {
        JChannel ch = new JChannel();
        ch.setReceiver(new ReceiverAdapter() {
            public void receive(Message msg) {
                System.out.println("received message " + msg.getObject());
            }
        });
        ch.connect("one");
    }
}

and this

package com.datacradle.example;

import org.jgroups.Global;
import org.jgroups.JChannel;
import org.jgroups.Message;
import org.jgroups.conf.ConfiguratorFactory;
import org.jgroups.conf.ProtocolConfiguration;
import org.jgroups.conf.ProtocolStackConfigurator;
import org.jgroups.stack.IpAddress;
import org.jgroups.util.SingletonAddress;
import org.jgroups.util.Util;

import java.util.List;

/**
 * @author Sergii.Zagriichuk
 */
public class Test {

    void start(String props) throws Exception {

        JChannel chanel = new JChannel();
        String line = "Test message";
        chanel.connect("one");
//        Message msg = new Message(null, null, new TestData(line, 1111, line + " Test suffix"));
                Message msg = new Message(new IpAddress("fe33:0:0:0:1986:ba23:d939:f226%12",55435) , null, new TestData(line,1111,line+" sdfasdfasdfasdfasdfa"));
        chanel.send(msg);
    }

    public static void main(final String[] args) throws Exception {
        new Test().start(null);
    }
}

So, If I use this style for creating message

 Message msg = new Message(null, null, new TestData(line, 1111, line + " Test suffix"));

I will receive just a one message(this is for all subscribers in current group), but if I use this style

Message msg = new Message(new IpAddress("fe33:0:0:0:1986:ba23:d939:f226%12",55435) , null, new TestData(line,1111,line+" sdfasdfasdfasdfasdfa"));

I will receive a lot of messages like in a loop (this is for one dist address) What is the problem or I should added some additional parameters?

P.S, JGroups 3.0.0 RC1

Thanks.

回答1:

You should not create a member address using the IpAddress class, as this is something that's opaque. I suggest fetch the target address from a view, e.g.

List<Address> members=channel.getView().getMembers();
Address target=members.get(0);
Message msg=new Message(target, null, "hello");
channel.send(msg);

来源：https://stackoverflow.com/questions/7585958/jgroups-sendnull-null-messagevs-sendaddress-null-message

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