com.ibm.jakarta.jms

Class JMSBytesMessage

  • All Implemented Interfaces:
    JmsMessage, jakarta.jms.BytesMessage, jakarta.jms.Message, java.io.Serializable


    public class JMSBytesMessage
    extends JMSMessage
    implements jakarta.jms.BytesMessage

    JMSBytesMessage is used to send a message containing a stream of uninterpreted bytes. The receiver of the message supplies the interpretation of the bytes.

    Its methods are based largely on those found in java.io.DataInputStream and java.io.DataOutputStream.

    This message type is for client encoding of existing message formats. If possible, one of the other self-defining message types should be used instead.

    Although JMS allows the use of message properties with byte messages, it is typically not done since the inclusion of properties affects the format.

    The primitive types can be written explicitly using methods for each type. They may also be written generically as objects. For example, a call to BytesMessage.writeInt(6) is equivalent to BytesMessage.writeObject(new Integer(6)). Both forms are provided because the explicit form is convenient for static programming and the object form is needed when types are not known at compile time.

    When the message is first created, or when clearBody() has been called, the body of the message is in write-only mode. After the first call to the reset method has been made, the message is in read-only mode. When a message has been sent, the provider always calls reset to read its content. Likewise, when a message has been received, the provider calls reset so that the message is in read-only mode for the client.

    If clearBody() is called on a message in read-only mode, the message body is cleared and the message is in write-only mode.

    If a client attempts to read a message in write-only mode, a MessageNotReadableException is thrown.

    If a client attempts to write a message in read-only mode, a MessageNotWriteableException is thrown.

    JMSBytesMessage can be used by a JMS application to read or write a message that is sent to or from a non-Java application. As this non-Java application might be hosted on a platform with different integer or floating point encoding conventions, the JMSBytesMessage class includes routines to represent its numeric data types in a number of different ways.

    The only character set supported by JMSBytesMessage is the Java version of UTF-8. This includes a two-byte length prefix, and is limited to strings less than 65536 bytes in long. Applications wanting to send a string in different character set have a choice of two methods:

    1. Send the message as a JMSTextMessage - if it is entirely made up of strings.
    2. Convert the String to a byte array and then write it into JMSBytesMessage using the writeBytes() method.

    The type of numeric encoding to be used can be set by the transport code when importing or exporting the message as a byte array. The type of encoding is specified using an int, which is effectively the sum of two separate enums. This follows the convention laid down by IBM MQ in the MQMD.encoding field. For convenience, the constants defined here take precisely the same values as their MQENC counterparts.

    To create a bytes message please call Session.createBytesMessage(). Do not call the default constructor.

    See Also:
    Serialized Form
    • Field Detail

      • sccsid

        public static final java.lang.String sccsid
        The SCCSID which is expanded when the file is extracted from CMVC
        See Also:
        Constant Field Values
    • Constructor Detail

      • JMSBytesMessage

        public JMSBytesMessage()
        Deprecated. 

        To create a bytes message please call Session.createBytesMessage().

        Do not call this default constructor.

    • Method Detail

      • getBodyLength

        public long getBodyLength()
                           throws jakarta.jms.JMSException
        Gets the number of bytes of the message body when the message is in read-only mode. The value returned can be used to allocate a byte array. The value returned is the entire length of the message body, regardless of where the pointer for reading the message is currently located.
        Specified by:
        getBodyLength in interface jakarta.jms.BytesMessage
        Returns:
        number of bytes in the message
        Throws:
        jakarta.jms.JMSException - if the operation fails
        jakarta.jms.MessageNotReadableException
      • readBoolean

        public boolean readBoolean()
                            throws jakarta.jms.JMSException
        Reads a boolean from the bytes message.
        Specified by:
        readBoolean in interface jakarta.jms.BytesMessage
        Returns:
        the boolean value read
        Throws:
        jakarta.jms.JMSException - if the operation fails
      • readByte

        public byte readByte()
                      throws jakarta.jms.JMSException
        Reads a signed 8-bit value from the bytes message.
        Specified by:
        readByte in interface jakarta.jms.BytesMessage
        Returns:
        the next byte from the bytes message as a signed 8-bit byte
        Throws:
        jakarta.jms.JMSException - if the operation fails
      • readBytes

        public int readBytes(byte[] value)
                      throws jakarta.jms.JMSException
        Reads a byte array from the bytes message. If there are sufficient bytes remaining in the stream the entire buffer is filled. If not, the buffer is partially filled.
        Specified by:
        readBytes in interface jakarta.jms.BytesMessage
        Parameters:
        value - the buffer into which the data is read.
        Returns:
        the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached
        Throws:
        jakarta.jms.JMSException - if the operation fails
      • readBytes

        public int readBytes(byte[] value,
                             int length)
                      throws jakarta.jms.JMSException
        Reads a portion of the bytes message.
        Specified by:
        readBytes in interface jakarta.jms.BytesMessage
        Parameters:
        value - the buffer into which the data is read.
        length - the number of bytes to read.
        Returns:
        the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached
        Throws:
        jakarta.jms.JMSException - if the operation fails
      • readChar

        public char readChar()
                      throws jakarta.jms.JMSException
        Reads a Unicode character value from the bytes message.
        Specified by:
        readChar in interface jakarta.jms.BytesMessage
        Returns:
        the next two bytes from the bytes message as a Unicode character
        Throws:
        jakarta.jms.JMSException - if the operation fails
      • readDouble

        public double readDouble()
                          throws jakarta.jms.JMSException
        Reads a double from the bytes message.
        Specified by:
        readDouble in interface jakarta.jms.BytesMessage
        Returns:
        the next eight bytes from the bytes message, interpreted as a double
        Throws:
        jakarta.jms.JMSException - if the operation fails
      • readFloat

        public float readFloat()
                        throws jakarta.jms.JMSException
        Reads a float from the bytes message.
        Specified by:
        readFloat in interface jakarta.jms.BytesMessage
        Returns:
        the next four bytes from the bytes message, interpreted as a float
        Throws:
        jakarta.jms.JMSException - if the operation fails
      • readInt

        public int readInt()
                    throws jakarta.jms.JMSException
        Reads a signed 32-bit integer from the bytes message.
        Specified by:
        readInt in interface jakarta.jms.BytesMessage
        Returns:
        the next four bytes from the bytes message, interpreted as an int.
        Throws:
        jakarta.jms.JMSException - if the operation fails
      • readLong

        public long readLong()
                      throws jakarta.jms.JMSException
        Reads a signed 64-bit integer from the bytes message.
        Specified by:
        readLong in interface jakarta.jms.BytesMessage
        Returns:
        the next eight bytes from the bytes message, interpreted as a long
        Throws:
        jakarta.jms.JMSException - if the operation fails
      • readShort

        public short readShort()
                        throws jakarta.jms.JMSException
        Reads a signed 16-bit number from the bytes message.
        Specified by:
        readShort in interface jakarta.jms.BytesMessage
        Returns:
        the next two bytes from the bytes message, interpreted as a signed 16-bit number.
        Throws:
        jakarta.jms.JMSException - if the operation fails
      • readUnsignedByte

        public int readUnsignedByte()
                             throws jakarta.jms.JMSException
        Reads an unsigned 8-bit number from the bytes message.
        Specified by:
        readUnsignedByte in interface jakarta.jms.BytesMessage
        Returns:
        the next byte from the bytes message, interpreted as an unsigned 8-bit number.
        Throws:
        jakarta.jms.JMSException - if the operation fails
      • readUnsignedShort

        public int readUnsignedShort()
                              throws jakarta.jms.JMSException
        Reads an unsigned 16-bit number from the bytes message.
        Specified by:
        readUnsignedShort in interface jakarta.jms.BytesMessage
        Returns:
        the next two bytes from the bytes message, interpreted as an unsigned 16-bit integer.
        Throws:
        jakarta.jms.JMSException - if the operation fails
      • readUTF

        public java.lang.String readUTF()
                                 throws jakarta.jms.JMSException
        Reads a string that has been encoded using a modified UTF-8 format from the bytes message.
        Specified by:
        readUTF in interface jakarta.jms.BytesMessage
        Returns:
        a Unicode string from the bytes message
        Throws:
        jakarta.jms.JMSException - if the operation fails
      • reset

        public void reset()
                   throws jakarta.jms.JMSException
        Puts the message in read-only mode, and repositions the stream of bytes to the beginning.
        Specified by:
        reset in interface jakarta.jms.BytesMessage
        Throws:
        jakarta.jms.JMSException - if JMS fails to reset the message due to some internal JMS error
        jakarta.jms.MessageFormatException - if message has an invalid format
      • writeBoolean

        public void writeBoolean(boolean value)
                          throws jakarta.jms.JMSException
        Writes a boolean to the bytes message as a 1-byte value. The value true is written out as the value (byte)1; the value false is written out as the value (byte)0.
        Specified by:
        writeBoolean in interface jakarta.jms.BytesMessage
        Parameters:
        value - the boolean value to be written
        Throws:
        jakarta.jms.JMSException - if the operation fails
      • writeByte

        public void writeByte(byte value)
                       throws jakarta.jms.JMSException
        Writes a byte to the bytes message as a 1-byte value.
        Specified by:
        writeByte in interface jakarta.jms.BytesMessage
        Parameters:
        value - the byte value to be written
        Throws:
        jakarta.jms.JMSException - if the operation fails
      • writeBytes

        public void writeBytes(byte[] value)
                        throws jakarta.jms.JMSException
        Writes a byte array to the bytes message.
        Specified by:
        writeBytes in interface jakarta.jms.BytesMessage
        Parameters:
        value - the byte array to be written.
        Throws:
        jakarta.jms.JMSException - if the operation fails
      • writeBytes

        public void writeBytes(byte[] value,
                               int offset,
                               int length)
                        throws jakarta.jms.JMSException
        Writes a portion of a byte array to the bytes message.
        Specified by:
        writeBytes in interface jakarta.jms.BytesMessage
        Parameters:
        value - the byte array value to be written
        offset - the initial offset within the byte array
        length - the number of bytes to use
        Throws:
        jakarta.jms.JMSException - if the operation fails
      • writeChar

        public void writeChar(char value)
                       throws jakarta.jms.JMSException
        Writes a char to the bytes message as a 2-byte value, high byte first.
        Specified by:
        writeChar in interface jakarta.jms.BytesMessage
        Parameters:
        value - the char value to be written
        Throws:
        jakarta.jms.JMSException - if the operation fails
      • writeDouble

        public void writeDouble(double value)
                         throws jakarta.jms.JMSException
        Converts the double argument to a long using the doubleToLongBits() method in class Double, and then writes that long value to the stream message as an 8-byte quantity, high byte first.
        Specified by:
        writeDouble in interface jakarta.jms.BytesMessage
        Parameters:
        value - the double value to be written
        Throws:
        jakarta.jms.JMSException - if the operation fails
      • writeFloat

        public void writeFloat(float value)
                        throws jakarta.jms.JMSException
        Converts the float argument to an int using the floatToIntBits() method in class Float, and then writes that int value to the stream message as a 4-byte quantity, high byte first.
        Specified by:
        writeFloat in interface jakarta.jms.BytesMessage
        Parameters:
        value - the float value to be written
        Throws:
        jakarta.jms.JMSException - if the operation fails
      • writeInt

        public void writeInt(int value)
                      throws jakarta.jms.JMSException
        Writes an int to the bytes message as four bytes, high byte first.
        Specified by:
        writeInt in interface jakarta.jms.BytesMessage
        Parameters:
        value - the int to be written
        Throws:
        jakarta.jms.JMSException - if the operation fails
      • writeLong

        public void writeLong(long value)
                       throws jakarta.jms.JMSException
        Writes a long to the bytes message as eight bytes, high byte first.
        Specified by:
        writeLong in interface jakarta.jms.BytesMessage
        Parameters:
        value - the long to be written
        Throws:
        jakarta.jms.JMSException - if the operation fails
      • writeObject

        public void writeObject(java.lang.Object value)
                         throws jakarta.jms.JMSException
        Writes a Java object to the bytes message.

        Note that this method only works for the primitive wrapper classes (Integer, Double, Long ...), Strings and byte arrays.

        Specified by:
        writeObject in interface jakarta.jms.BytesMessage
        Parameters:
        value - the Java Object to be written
        Throws:
        jakarta.jms.JMSException - if the operation fails
      • writeShort

        public void writeShort(short value)
                        throws jakarta.jms.JMSException
        Writes a short to the bytes message as two bytes, high byte first.
        Specified by:
        writeShort in interface jakarta.jms.BytesMessage
        Parameters:
        value - the short to be written.
        Throws:
        jakarta.jms.JMSException - if the operation fails
      • writeUTF

        public void writeUTF(java.lang.String value)
                      throws jakarta.jms.JMSException
        Writes a string to the BytesMessage using UTF-8 encoding in a machine-independent manner.
        Specified by:
        writeUTF in interface jakarta.jms.BytesMessage
        Parameters:
        value - the String value to be written.
        Throws:
        jakarta.jms.JMSException - if the operation fails
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