8
Napisałem program w języku Java, aby połączyć się z Websphere MQ w celu opublikowania wiadomości. Utworzono przestrzeń nazw JNDI, fabrykę połączeń, miejsca docelowe i menedżera kolejek w przeglądarce Websphere MQ Explore. Kiedy uruchamiam program, wyświetlany jest kod ClassCastException dla odlewania od string do ConnectionFactory.ClassCastException: javax.naming.Reference nie może być rzutowany na javax.jms.ConnectionFactory
Oto mój kod. Czy ktoś może pomóc rozwiązać ten problem.
JNDIUtil.java
package com.tradefinance.jms.util;
//JMS classes
import javax.jms.JMSException;
import javax.jms.ConnectionFactory;
import javax.jms.Destination;
//JNDI classes
import javax.naming.InitialContext;
import javax.naming.Context;
import javax.naming.NamingException;
//Standard Java classes
import java.util.Hashtable;
import java.util.Properties;
/**
*
* A wrapper class for JNDI calls
*
*/
public class JNDIUtil
{
private Context context;
public JNDIUtil(String icf, String url) throws JMSException, NamingException
{
Hashtable environment = new Hashtable();
environment.put(Context.INITIAL_CONTEXT_FACTORY, icf);
environment.put(Context.PROVIDER_URL, url);
context= new InitialContext(environment);
}
/**
* @param ObjName Object Name to be retrieved
* @return Retrieved Object
* @throws NamingException
*/
private Object getObjectByName(String ObjName) throws NamingException
{
return context.lookup(ObjName);
}
/**
* @param factoryName Factory Name
* @return ConnectionFactory object
* @throws NamingException
*/
public ConnectionFactory getConnectionFactory(String factoryName) throws NamingException
{
return (ConnectionFactory) getObjectByName(factoryName);
}
/**
* @param destinationName Destination Name
* @return ConnectionFactory object
* @throws NamingException
*/
public Destination getDestination(String destinationName) throws NamingException
{
return (Destination) getObjectByName(destinationName);
}
}
NewPublisher.java
package com.tradefinance.jms.topics;
//JMS classes
import javax.jms.JMSException;
import javax.jms.ConnectionFactory;
import javax.jms.Connection;
import javax.jms.Session;
import javax.jms.Destination;
import javax.jms.MessageProducer;
import javax.jms.TextMessage;
//JNDI classes
import javax.naming.NamingException;
import com.tradefinance.jms.util.JNDIUtil;
/**
* A class to demonstrate how to a publish to a topic.
*/
public class NewsPublisher
{
public static String icf = "com.sun.jndi.fscontext.RefFSContextFactory";
public static String url = "file:/C:/JNDI-Directory/";
public static void main(String[] vars) throws JMSException, NamingException
{
ConnectionFactory factory = null;
Connection connection = null;
Session session = null;
Destination destination= null; // a destination can be a topic or a queue
MessageProducer producer= null;
try
{
JNDIUtil jndiUtil= new JNDIUtil(icf,url);
factory= jndiUtil.getConnectionFactory("TestQM1ConnectionFactory");
connection = factory.createConnection();
connection.start();
// Indicate a non-transactional session
boolean transacted = false;
session = connection.createSession(transacted, Session.AUTO_ACKNOWLEDGE);
destination = jndiUtil.getDestination("NewsTopic");
producer = session.createProducer(destination);
TextMessage message = session.createTextMessage("No News is Good News!");
producer.send(message);
System.out.println("NewsPublisher: Message Publication Completed");
}
finally
{
// Always release resources
if (producer!= null)
producer.close();
if (session!= null)
session.close();
if (connection!= null)
connection.close();
}
}
}
Uzyskiwanie błąd na tych liniach:
return (ConnectionFactory) getObjectByName(factoryName);
in JNDIUtil.java
factory= jndiUtil.getConnectionFactory("TestQM1ConnectionFactory");
in NewPublisher.java