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Thread: passing java objects to ActiveMQ(JMS)

  1. #1
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    Default passing java objects to ActiveMQ(JMS)

    Hi,

    I'm new to this jms. i have written a program to pass java objects to the JMS but i'm getting error as Exception in thread "main" java.lang.NullPointerException, When i run producer.java programme. So please let me know whats wrong in my program.

    Here is the code..

    ******************************************
    TestPro.java
    ******************************************

    package com.test.msg;

    import java.io.Serializable;

    public class TestPro implements Serializable
    {
    private String msg;

    public String getMsg() {
    return msg;
    }

    public void setMsg(String msg) {
    this.msg = msg;
    }
    }

    **************************************
    producer.java
    ***************************************

    package com.test.producer;

    import javax.jms.*;

    import org.apache.activemq.ActiveMQConnectionFactory;

    import com.test.msg.TestPro;

    public class Producer {

    private static String url = "tcp://localhost:5003";
    public static Connection connection;
    private static String TEST_QUEUE = "TEST";

    public static MessageProducer producer;
    public Session session;
    String TEST_MESSAGE;

    public static void main(String[] args) throws JMSException
    {
    ConnectionFactory connectionFactory = new ActiveMQConnectionFactory(url);
    connection = connectionFactory.createConnection();
    connection.start();

    Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);

    Destination destination = session.createQueue(TEST_QUEUE);
    producer = session.createProducer(destination);
    //TextMessage message = session.createTextMessage("Hello Rohith WelCome To ActiveMQ");
    Producer produce = new Producer();
    TestPro testPro = new TestPro();
    testPro.setMsg("Hello......");
    produce.sendData(testPro);

    }

    public void sendData(TestPro message) throws JMSException
    {
    ObjectMessage objectMessage = session.createObjectMessage();
    objectMessage.setObject(message);
    objectMessage.setJMSCorrelationID("ID:"+ TEST_MESSAGE);
    producer.send(objectMessage);
    System.out.println("Send Message" +(String)objectMessage.getObject());
    connection.close();
    }
    }
    *************************************************
    cunsumer.java
    ***********************************************

    package com.test.consumer;

    import javax.jms.*;

    import org.apache.activemq.ActiveMQConnectionFactory;

    public class Consumer {

    private static String url = "tcp://localhost:5003";
    public static Connection connection;
    private static String TEST_QUEUE = "TEST_QUEUE";

    public static MessageConsumer consumer;

    public static void main(String arg[]) throws JMSException
    {
    ConnectionFactory connectionFactory = new ActiveMQConnectionFactory(url);
    Connection connection = connectionFactory.createConnection();
    connection.start();

    Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
    Destination destination = session.createQueue(TEST_QUEUE);
    consumer = session.createConsumer(destination);
    /*Message message = consumer.receive();

    if(message instanceof TextMessage)
    {
    TextMessage textMessage = (TextMessage)message;
    System.out.println("Received Message " + textMessage.getText());
    }*/
    Consumer consume = new Consumer();
    consume.onMessage(message)
    }

    public void onMessage(Message message) throws JMSException
    {
    ObjectMessage objectMessage = (ObjectMessage) message;
    System.out.println("Receive Message: " + (String)objectMessage.getObject());
    connection.close();
    }

    }
    ************************************************** ***
    In consuner.java how to make main method to access onMessage menthod... Please help........


  2. #2
    Super Moderator Norm's Avatar
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    Default Re: passing java objects to ActiveMQ(JMS)

    getting error as Exception in thread "main" java.lang.NullPointerException
    The full text of the error message gives the line number where the exception occurred. Look at that line and find the variable that has a null value. Then backtrack in your code to find out why that variable does not have a valid non null value.
    If you can not tell which variable is null, use the println statement to print out the values of all the variables used on the line with the error.
    If you don't understand my answer, don't ignore it, ask a question.

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