ZeroMQ--使用jzmq进行编程

一、环境搭建

wget http://download.zeromq.org/zeromq-2.1.7.tar.gz
tar -xzf zeromq-2.1.7.tar.gz
cd zeromq-2.1.7
./configure
make
sudo make install

git clone https://github.com/nathanmarz/jzmq.git
cd jzmq
./autogen.sh
./configure
make
sudo make install

如果没有安装libtool、libuuid-devel则需要先安装，否则安装失败
yum install libtool
yum install libuuid-devel

常见问题：

出现java.lang.UnsatisfiedLinkError: /usr/local/lib/libjzmq.so.0.0.0: libzmq.so.1: cannot open shared object file: No such file or directory异常
原因是未找到zmq动态链接库。
解决方法1：export LD_LIBRARY_PATH=/usr/local/lib
解决方法2：编辑/etc/ld.so.conf文件，增加一行：/usr/local/lib。再执行sudo ldconfig命令

Exception in thread "main" java.lang.UnsatisfiedLinkError: no jzmq in java.library.path
未设置native library
在eclipse设置native library为/usr/local/lib
或在jvm增加参数
-Djava.library.path=/usr/local/lib
或在启动脚本中增加
java -Djava.library.path=/usr/local/lib

二、使用jzmq进行编程

    1.创建maven项目，pom.xml的内容参见pom.xml

      注意：jzmq的版本不能太高，建议使用2.1.0，目前storm也是使用这个版本的jzmq-2.1.0.jar

      否则报： java.lang.UnsatisfiedLinkError: org.zeromq.ZMQ$Socket.nativeInit()V

    2.编写Publisher.java,Subscriber.java,参见源代码

    Publisher.java  

package com.catt.mqtest.pubsub;


import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.zeromq.ZMQ;
import org.zeromq.ZMQ.Context;
import org.zeromq.ZMQ.Socket;

public class Publisher {

	// 等待10个订阅者
	private static final int SUBSCRIBERS_EXPECTED = 10;
	// 定义一个全局的记录器，通过LoggerFactory获取
	private final static Logger log = LoggerFactory.getLogger(Publisher.class);

	public static void main(String[] args) throws InterruptedException{
		Context context = ZMQ.context(1);
		Socket publisher = context.socket(ZMQ.PUB);
		publisher.bind("tcp://*:5557");
		try {
			// zmq发送速度太快，在订阅者尚未与发布者建立联系时，已经开始了数据发布
			Thread.sleep(1000);
		} catch (InterruptedException e) {
			e.printStackTrace();
		}

		publisher.send("send start......".getBytes(), 0);
		for (int i = 0; i < 10; i++) {
			publisher.send(("Hello world "+i).getBytes(), ZMQ.NOBLOCK);
		}
		publisher.send("send end......".getBytes(), 0);

		publisher.close();
		context.term();
	}
}

Subscriber.java

package com.catt.mqtest.pubsub;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.zeromq.ZMQ;
import org.zeromq.ZMQ.Context;
import org.zeromq.ZMQ.Socket;

public class Subscriber {

	// 定义一个全局的记录器，通过LoggerFactory获取
	private final static Logger log = LoggerFactory.getLogger(Subscriber.class);

	public static void main(String[] args) {
		Context context = ZMQ.context(1);
		Socket subscriber = context.socket(ZMQ.SUB);
		subscriber.connect("tcp://192.168.230.128:5557");
		subscriber.subscribe("".getBytes());
		int total = 0;
		while (true) {
			byte[] stringValue = subscriber.recv(0);
			String string = new String(stringValue);
			if (string.equals("send end......")) {
				break;
			}
			total++;
			System.out.println("Received " + total + " updates. :" + string);
		}

		subscriber.close();
		context.term();
	}
}

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>

	<groupId>com.catt</groupId>
	<artifactId>mqtest</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>mqtest</name>
	<url>http://maven.apache.org</url>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
	</properties>

	<dependencies>
		<dependency>
			<groupId>org.zeromq</groupId>
			<artifactId>jzmq</artifactId>
			<version>2.1.0</version>
		</dependency>
		<dependency>
			<groupId>ch.qos.logback</groupId>
			<artifactId>logback-classic</artifactId>
			<version>1.1.1</version>
		</dependency>
		<dependency>
			<groupId>junit</groupId>
			<artifactId>junit</artifactId>
			<version>4.10</version>
			<scope>test</scope>
		</dependency>
	</dependencies>
</project>