messageformats.java

JMS的例子程序

/*
 * @(#)MessageFormats.java	1.4 00/08/09
 * 
 * Copyright (c) 2000 Sun Microsystems, Inc. All Rights Reserved.
 * 
 * Sun grants you ("Licensee") a non-exclusive, royalty free, license to use,
 * modify and redistribute this software in source and binary code form,
 * provided that i) this copyright notice and license appear on all copies of
 * the software; and ii) Licensee does not utilize the software in a manner
 * which is disparaging to Sun.
 *
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY
 * IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
 * NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE
 * LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
 * OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS
 * LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT,
 * INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
 * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF
 * OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 *
 * This software is not designed or intended for use in on-line control of
 * aircraft, air traffic, aircraft navigation or aircraft communications; or in
 * the design, construction, operation or maintenance of any nuclear
 * facility. Licensee represents and warrants that it will not use or
 * redistribute the Software for such purposes.
 */
import javax.jms.*;

/**
 * The MessageFormats class consists only of a main method, which creates and 
 * then reads messages in all supported JMS message formats:  BytesMessage, 
 * TextMessage, MapMessage, StreamMessage, and ObjectMessage.  It does not send 
 * the messages.
 * <p>
 * Before it can read a BytesMessage or StreamMessage that has not been sent,
 * the program must call reset() to put the message body in read-only mode 
 * and reposition the stream.
 *
 * @author Kim Haase
 * @version 1.4, 08/09/00
 */
public class MessageFormats {

    /**
     * Main method.  Takes no arguments.
     */
    public static void main(String[] args) {
        QueueConnectionFactory  queueConnectionFactory = null;
        QueueConnection         queueConnection = null;
        QueueSession            queueSession = null;
        BytesMessage            bytesMessage = null;
        byte[]                  byteData = {-128, 127, -1, 0, 1, -64, 64};
        int                     length = 0;
        byte[]                  inByteData = new byte[7];
        TextMessage             textMessage = null;
        String                  msgText = "This is a text message.";
        MapMessage              mapMessage = null;
        StreamMessage           streamMessage = null;
        ObjectMessage           objectMessage = null;
        String                  object = "A String is an object.";
        int                     exitResult = 0;

    	try {
            queueConnectionFactory = 
                SampleUtilities.getQueueConnectionFactory();
    	    queueConnection = 
    	        queueConnectionFactory.createQueueConnection();
    	    queueSession = queueConnection.createQueueSession(false, 
    	        Session.AUTO_ACKNOWLEDGE);
    	} catch (Exception e) {
            System.out.println("Connection problem: " + e.toString());
            if (queueConnection != null) {
                try {
                    queueConnection.close();
                } catch (JMSException ee) {}
            }
    	    System.exit(1);
    	} 

        try {
    	    /*
    	     * Create a BytesMessage, then write it from an array of
    	     * bytes (signed 8-bit integers). 
    	     * Reset the message for reading, then read the bytes into a
    	     * second array.
    	     * A BytesMessage is an undifferentiated stream of bytes that can
    	     * be read in various formats.
    	     */
    	    bytesMessage = queueSession.createBytesMessage();
    	    bytesMessage.writeBytes(byteData);
    	    bytesMessage.reset();
            length = bytesMessage.readBytes(inByteData);
            System.out.println("Reading BytesMessage " + length
                + " bytes long:");
            for (int i = 0; i < length; i++) {
                System.out.print("  " + inByteData[i]);
            }
    	    System.out.println();
    	    
    	    /* 
    	     * Create, write, and display the contents of a TextMessage.
    	     * A TextMessage contains a String of any length. 
    	     */
    	    textMessage = queueSession.createTextMessage();
    	    textMessage.setText(msgText);
            System.out.println("Reading TextMessage:");
            System.out.println(" " + textMessage.getText());
    	    
    	    /* 
    	     * Create and write a MapMessage, then display its contents in
    	     * a different order.
    	     * A MapMessage contains a series of name/value pairs.
    	     * The name is a string; the value can be of various types.
    	     * The receiving program can read any or all of the values,
    	     * in any order.
    	     */
    	    mapMessage = queueSession.createMapMessage();
    	    mapMessage.setString("Message type", "Map");
    	    mapMessage.setInt("An Integer", 3456);
    	    mapMessage.setDouble("A Double", 1.23456789);
            System.out.println("Reading MapMessage in a different order"
                + " from the way it was generated:");
            System.out.println(" Type: " 
                + mapMessage.getString("Message type"));
            System.out.println(" Double: "
                + mapMessage.getDouble("A Double"));
            System.out.println(" Integer: " 
                + mapMessage.getInt("An Integer"));
   	        
    	    /* 
    	     * Create and write a StreamMessage.
    	     * Reset the message for reading and display the values.
    	     * A StreamMessage can also contain values of various types.
    	     * They must be read in the same order in which they were
    	     * written.
    	     */
    	    streamMessage = queueSession.createStreamMessage();
    	    streamMessage.writeString("Stream message");
    	    streamMessage.writeDouble(123.456789e222);
    	    streamMessage.writeInt(223344);
    	    streamMessage.reset();
            System.out.println("Reading StreamMessage in the order"
                + " in which it was generated:");
            System.out.println(" String: " 
                + streamMessage.readString());
            System.out.println(" Double: "
                + streamMessage.readDouble());
            System.out.println(" Integer: " 
                + streamMessage.readInt());
    	    
    	    /* 
    	     * Create an ObjectMessage from a String object, then
    	     * display its contents.
    	     * An ObjectMessage can contain any Java object.  This example
    	     * uses a String for the sake of simplicity.  The program that
    	     * reads the object casts it to the appropriate type.
    	     */
    	    objectMessage = queueSession.createObjectMessage();
    	    objectMessage.setObject(object);
            System.out.println("Reading ObjectMessage:");
            System.out.println(" " + (String) objectMessage.getObject()); 

    	} catch (JMSException e) {
    	    System.out.println("Exception occurred: " + e.toString());
    	    exitResult = 1;
    	} finally {
            if (queueConnection != null) {
                try {
                    queueConnection.close();
                } catch (JMSException e) {
    	            exitResult = 1;
                }
    	    }
    	}
    	SampleUtilities.exit(exitResult);
    }
}