* 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) { ConnectionFactory connectionFactory = null; Connection connection = null; Session session = 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 { connectionFactory = SampleUtilities.getConnectionFactory(); connection = connectionFactory.createConnection(); session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE); } catch (Exception e) { System.out.println("Connection problem: " + e.toString()); if (connection != null) { try { connection.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 = session.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 = session.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 = session.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 = session.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 = session.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 (connection != null) { try { connection.close(); } catch (JMSException e) { exitResult = 1; } } } SampleUtilities.exit(exitResult); } } jms.zip( 65 k)