编辑:重新表述问题:
我想在我的服务器和客户端应用程序之间使用ActiveMQ作为信使服务。
我正在尝试设置一个嵌入式代理(即不是一个单独的进程),以处理为我的客户生成的消息。这个队列是持久化的。
代理的初始化如下:
BrokerService broker = new BrokerService();
KahaPersistenceAdapter adaptor = new KahaPersistenceAdapter();
adaptor.setDirectory(new File("activemq"));
broker.setPersistenceAdapter(adaptor);
broker.setUseJmx(true);
broker.addConnector("tcp://localhost:61616");
broker.start();
经过一番调试之后,我最终得到的服务器部分代码是:
public static class HelloWorldProducer implements Runnable {
public void run() {
try {
ActiveMQConnectionFactory connectionFactory = new ActiveMQConnectionFactory("tcp://localhost"); // apparently the vm part is all i need
Connection connection = connectionFactory.createConnection();
connection.start();
Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
Destination destination = session.createQueue("TEST.FOO");
MessageProducer producer = session.createProducer(destination);
producer.setDeliveryMode(DeliveryMode.NON_PERSISTENT);
String text = "Hello world! From: " + Thread.currentThread().getName() + " : " + this.hashCode();
TextMessage message = session.createTextMessage(text);
System.out.println("Sent message: "+ message.hashCode() + " : " + Thread.currentThread().getName());
producer.send(message);
session.close();
connection.close();
}
catch (Exception e) {
System.out.println("Caught: " + e);
e.printStackTrace();
}
}
}
客户端非常相似,看起来像这样:
public static class HelloWorldConsumer implements Runnable, ExceptionListener {
public void run() {
try {
ActiveMQConnectionFactory connectionFactory = new ActiveMQConnectionFactory("tcp://localhost");
Connection connection = connectionFactory.createConnection(); // exception happens here...
connection.start();
connection.setExceptionListener(this);
Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
Destination destination = session.createQueue("TEST.FOO");
MessageConsumer consumer = session.createConsumer(destination);
Message message = consumer.receive(1000);
if (message instanceof TextMessage) {
TextMessage textMessage = (TextMessage) message;
String text = textMessage.getText();
System.out.println("*****Received: " + text);
} else {
System.out.println("*****Received obj: " + message);
}
consumer.close();
session.close();
connection.close();
} catch (Exception e) {
System.out.println("Caught: " + e);
e.printStackTrace();
}
}
主方法只是启动每个线程以开始生产/接收消息。
...但我在每个线程的启动时遇到了以下问题:
2013-01-24 07:54:31,271 INFO [org.apache.activemq.broker.BrokerService] Using Persistence Adapter: AMQPersistenceAdapter(activemq-data/localhost)
2013-01-24 07:54:31,281 INFO [org.apache.activemq.store.amq.AMQPersistenceAdapter] AMQStore starting using directory: activemq-data/localhost
2013-01-24 07:54:31,302 INFO [org.apache.activemq.kaha.impl.KahaStore] Kaha Store using data directory activemq-data/localhost/kr-store/state
2013-01-24 07:54:31,339 INFO [org.apache.activemq.store.amq.AMQPersistenceAdapter] Active data files: []
2013-01-24 07:54:31,445 DEBUG [org.apache.activemq.broker.jmx.ManagementContext] Probably not using JRE 1.4: mx4j.tools.naming.NamingService
2013-01-24 07:54:31,450 DEBUG [org.apache.activemq.broker.jmx.ManagementContext] Failed to create local registry
java.rmi.server.ExportException: internal error: ObjID already in use
at sun.rmi.transport.ObjectTable.putTarget(ObjectTable.java:186)
at sun.rmi.transport.Transport.exportObject(Transport.java:92)
at sun.rmi.transport.tcp.TCPTransport.exportObject(TCPTransport.java:247)
at sun.rmi.transport.tcp.TCPEndpoint.exportObject(TCPEndpoint.java:411)
at sun.rmi.transport.LiveRef.exportObject(LiveRef.java:147)
<snip....>
看起来消息已经成功地生产和消费了(我之前发布的其他问题已经解决),但上述异常让我感到担忧。
编辑:在代理器关闭期间,我现在也收到了以下提示:
2013-01-25 08:40:17,486 DEBUG [org.apache.activemq.transport.failover.FailoverTransport] Transport failed with the following exception:
java.io.EOFException
at java.io.DataInputStream.readInt(DataInputStream.java:392)
at org.apache.activemq.openwire.OpenWireFormat.unmarshal(OpenWireFormat.java:269)
at org.apache.activemq.transport.tcp.TcpTransport.readCommand(TcpTransport.java:210)
at org.apache.activemq.transport.tcp.TcpTransport.doRun(TcpTransport.java:202)
at org.apache.activemq.transport.tcp.TcpTransport.run(TcpTransport.java:185)
at java.lang.Thread.run(Thread.java:722)