javax.jms

Interface BytesMessage

All Superinterfaces:

Message

public interface BytesMessage
extends Message

A BytesMessage object is used to send a message containing a stream of uninterpreted bytes. It inherits from the Message interface and adds a bytes message body. The receiver of the message supplies the interpretation of the bytes.

The BytesMessage 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 the JMS API allows the use of message properties with byte messages, they are typically not used, since the inclusion of properties may affect the format.

The primitive types can be written explicitly using methods for each type. They may also be written generically as objects. For instance, 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, and when clearBody is called, the body of the message is in write-only mode. After the first call to reset has been made, the message body is in read-only mode. After a message has been sent, the client that sent it can retain and modify it without affecting the message that has been sent. The same message object can be sent multiple times. When a message has been received, the provider has called reset so that the message body 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.

Version:

1.1 April 2, 2002

See Also:

Session.createBytesMessage(), MapMessage, Message, ObjectMessage, StreamMessage, TextMessage

Field Summary

Fields inherited from interface javax.jms.Message

DEFAULT_DELIVERY_MODE, DEFAULT_PRIORITY, DEFAULT_TIME_TO_LIVE

Method Summary

Modifier and Type	Method and Description
long	getBodyLength() Gets the number of bytes of the message body when the message is in read-only mode.
boolean	readBoolean() Reads a boolean from the bytes message stream.
byte	readByte() Reads a signed 8-bit value from the bytes message stream.
int	readBytes(byte[] value) Reads a byte array from the bytes message stream.
int	readBytes(byte[] value, int length) Reads a portion of the bytes message stream.
char	readChar() Reads a Unicode character value from the bytes message stream.
double	readDouble() Reads a double from the bytes message stream.
float	readFloat() Reads a float from the bytes message stream.
int	readInt() Reads a signed 32-bit integer from the bytes message stream.
long	readLong() Reads a signed 64-bit integer from the bytes message stream.
short	readShort() Reads a signed 16-bit number from the bytes message stream.
int	readUnsignedByte() Reads an unsigned 8-bit number from the bytes message stream.
int	readUnsignedShort() Reads an unsigned 16-bit number from the bytes message stream.
String	readUTF() Reads a string that has been encoded using a modified UTF-8 format from the bytes message stream.
void	reset() Puts the message body in read-only mode and repositions the stream of bytes to the beginning.
void	writeBoolean(boolean value) Writes a boolean to the bytes message stream as a 1-byte value.
void	writeByte(byte value) Writes a byte to the bytes message stream as a 1-byte value.
void	writeBytes(byte[] value) Writes a byte array to the bytes message stream.
void	writeBytes(byte[] value, int offset, int length) Writes a portion of a byte array to the bytes message stream.
void	writeChar(char value) Writes a char to the bytes message stream as a 2-byte value, high byte first.
void	writeDouble(double value) Converts the double argument to a long using the doubleToLongBits method in class Double, and then writes that long value to the bytes message stream as an 8-byte quantity, high byte first.
void	writeFloat(float value) Converts the float argument to an int using the floatToIntBits method in class Float, and then writes that int value to the bytes message stream as a 4-byte quantity, high byte first.
void	writeInt(int value) Writes an int to the bytes message stream as four bytes, high byte first.
void	writeLong(long value) Writes a long to the bytes message stream as eight bytes, high byte first.
void	writeObject(Object value) Writes an object to the bytes message stream.
void	writeShort(short value) Writes a short to the bytes message stream as two bytes, high byte first.
void	writeUTF(String value) Writes a string to the bytes message stream using UTF-8 encoding in a machine-independent manner.

Methods inherited from interface javax.jms.Message

acknowledge, clearBody, clearProperties, getBooleanProperty, getByteProperty, getDoubleProperty, getFloatProperty, getIntProperty, getJMSCorrelationID, getJMSCorrelationIDAsBytes, getJMSDeliveryMode, getJMSDestination, getJMSExpiration, getJMSMessageID, getJMSPriority, getJMSRedelivered, getJMSReplyTo, getJMSTimestamp, getJMSType, getLongProperty, getObjectProperty, getPropertyNames, getShortProperty, getStringProperty, propertyExists, setBooleanProperty, setByteProperty, setDoubleProperty, setFloatProperty, setIntProperty, setJMSCorrelationID, setJMSCorrelationIDAsBytes, setJMSDeliveryMode, setJMSDestination, setJMSExpiration, setJMSMessageID, setJMSPriority, setJMSRedelivered, setJMSReplyTo, setJMSTimestamp, setJMSType, setLongProperty, setObjectProperty, setShortProperty, setStringProperty

Method Detail

getBodyLength

long getBodyLength()
            throws 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.

Returns:

number of bytes in the message

Throws:

JMSException - if the JMS provider fails to read the message due to some internal error.

MessageNotReadableException - if the message is in write-only mode.

Since:

1.1

readBoolean

boolean readBoolean()
             throws JMSException

Reads a boolean from the bytes message stream.

Returns:

the boolean value read

Throws:

JMSException - if the JMS provider fails to read the message due to some internal error.

MessageEOFException - if unexpected end of bytes stream has been reached.

MessageNotReadableException - if the message is in write-only mode.

readByte

byte readByte()
       throws JMSException

Reads a signed 8-bit value from the bytes message stream.

Returns:

the next byte from the bytes message stream as a signed 8-bit byte

Throws:

JMSException - if the JMS provider fails to read the message due to some internal error.

MessageEOFException - if unexpected end of bytes stream has been reached.

MessageNotReadableException - if the message is in write-only mode.

readUnsignedByte

int readUnsignedByte()
              throws JMSException

Reads an unsigned 8-bit number from the bytes message stream.

Returns:

the next byte from the bytes message stream, interpreted as an unsigned 8-bit number

Throws:

JMSException - if the JMS provider fails to read the message due to some internal error.

MessageEOFException - if unexpected end of bytes stream has been reached.

MessageNotReadableException - if the message is in write-only mode.

readShort

short readShort()
         throws JMSException

Reads a signed 16-bit number from the bytes message stream.

Returns:

the next two bytes from the bytes message stream, interpreted as a signed 16-bit number

Throws:

JMSException - if the JMS provider fails to read the message due to some internal error.

MessageEOFException - if unexpected end of bytes stream has been reached.

MessageNotReadableException - if the message is in write-only mode.

readUnsignedShort

int readUnsignedShort()
               throws JMSException

Reads an unsigned 16-bit number from the bytes message stream.

Returns:

the next two bytes from the bytes message stream, interpreted as an unsigned 16-bit integer

Throws:

JMSException - if the JMS provider fails to read the message due to some internal error.

MessageEOFException - if unexpected end of bytes stream has been reached.

MessageNotReadableException - if the message is in write-only mode.

readChar

char readChar()
       throws JMSException

Reads a Unicode character value from the bytes message stream.

Returns:

the next two bytes from the bytes message stream as a Unicode character

Throws:

JMSException - if the JMS provider fails to read the message due to some internal error.

MessageEOFException - if unexpected end of bytes stream has been reached.

MessageNotReadableException - if the message is in write-only mode.

readInt

int readInt()
     throws JMSException

Reads a signed 32-bit integer from the bytes message stream.

Returns:

the next four bytes from the bytes message stream, interpreted as an int

Throws:

JMSException - if the JMS provider fails to read the message due to some internal error.

MessageEOFException - if unexpected end of bytes stream has been reached.

MessageNotReadableException - if the message is in write-only mode.

readLong

long readLong()
       throws JMSException

Reads a signed 64-bit integer from the bytes message stream.

Returns:

the next eight bytes from the bytes message stream, interpreted as a long

Throws:

JMSException - if the JMS provider fails to read the message due to some internal error.

MessageEOFException - if unexpected end of bytes stream has been reached.

MessageNotReadableException - if the message is in write-only mode.

readFloat

float readFloat()
         throws JMSException

Reads a float from the bytes message stream.

Returns:

the next four bytes from the bytes message stream, interpreted as a float

Throws:

JMSException - if the JMS provider fails to read the message due to some internal error.

MessageEOFException - if unexpected end of bytes stream has been reached.

MessageNotReadableException - if the message is in write-only mode.

readDouble

double readDouble()
           throws JMSException

Reads a double from the bytes message stream.

Returns:

the next eight bytes from the bytes message stream, interpreted as a double

Throws:

JMSException - if the JMS provider fails to read the message due to some internal error.

MessageEOFException - if unexpected end of bytes stream has been reached.

MessageNotReadableException - if the message is in write-only mode.

readUTF

String readUTF()
        throws JMSException

Reads a string that has been encoded using a modified UTF-8 format from the bytes message stream.

For more information on the UTF-8 format, see "File System Safe UCS Transformation Format (FSS_UTF)", X/Open Preliminary Specification, X/Open Company Ltd., Document Number: P316. This information also appears in ISO/IEC 10646, Annex P.

Returns:

a Unicode string from the bytes message stream

Throws:

JMSException - if the JMS provider fails to read the message due to some internal error.

MessageEOFException - if unexpected end of bytes stream has been reached.

MessageNotReadableException - if the message is in write-only mode.

readBytes

int readBytes(byte[] value)
       throws JMSException

Reads a byte array from the bytes message stream.

If the length of array value is less than the number of bytes remaining to be read from the stream, the array should be filled. A subsequent call reads the next increment, and so on.

If the number of bytes remaining in the stream is less than the length of array value, the bytes should be read into the array. The return value of the total number of bytes read will be less than the length of the array, indicating that there are no more bytes left to be read from the stream. The next read of the stream returns -1.

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:

JMSException - if the JMS provider fails to read the message due to some internal error.

MessageNotReadableException - if the message is in write-only mode.

readBytes

int readBytes(byte[] value,
              int length)
       throws JMSException

Reads a portion of the bytes message stream.

If the length of array value is less than the number of bytes remaining to be read from the stream, the array should be filled. A subsequent call reads the next increment, and so on.

If the number of bytes remaining in the stream is less than the length of array value, the bytes should be read into the array. The return value of the total number of bytes read will be less than the length of the array, indicating that there are no more bytes left to be read from the stream. The next read of the stream returns -1.

If length is negative, or length is greater than the length of the array value, then an IndexOutOfBoundsException is thrown. No bytes will be read from the stream for this exception case.

Parameters:

value - the buffer into which the data is read

length - the number of bytes to read; must be less than or equal to value.length

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:

JMSException - if the JMS provider fails to read the message due to some internal error.

MessageNotReadableException - if the message is in write-only mode.

writeBoolean

void writeBoolean(boolean value)
           throws JMSException

Writes a boolean to the bytes message stream as a 1-byte value. The value true is written as the value (byte)1; the value false is written as the value (byte)0.

Parameters:

value - the boolean value to be written

Throws:

JMSException - if the JMS provider fails to write the message due to some internal error.

MessageNotWriteableException - if the message is in read-only mode.

writeByte

void writeByte(byte value)
        throws JMSException

Writes a byte to the bytes message stream as a 1-byte value.

Parameters:

value - the byte value to be written

Throws:

JMSException - if the JMS provider fails to write the message due to some internal error.

MessageNotWriteableException - if the message is in read-only mode.

writeShort

void writeShort(short value)
         throws JMSException

Writes a short to the bytes message stream as two bytes, high byte first.

Parameters:

value - the short to be written

Throws:

JMSException - if the JMS provider fails to write the message due to some internal error.

MessageNotWriteableException - if the message is in read-only mode.

writeChar

void writeChar(char value)
        throws JMSException

Writes a char to the bytes message stream as a 2-byte value, high byte first.

Parameters:

value - the char value to be written

Throws:

JMSException - if the JMS provider fails to write the message due to some internal error.

MessageNotWriteableException - if the message is in read-only mode.

writeInt

void writeInt(int value)
       throws JMSException

Writes an int to the bytes message stream as four bytes, high byte first.

Parameters:

value - the int to be written

Throws:

JMSException - if the JMS provider fails to write the message due to some internal error.

MessageNotWriteableException - if the message is in read-only mode.

writeLong

void writeLong(long value)
        throws JMSException

Writes a long to the bytes message stream as eight bytes, high byte first.

Parameters:

value - the long to be written

Throws:

JMSException - if the JMS provider fails to write the message due to some internal error.

MessageNotWriteableException - if the message is in read-only mode.

writeFloat

void writeFloat(float value)
         throws JMSException

Converts the float argument to an int using the floatToIntBits method in class Float, and then writes that int value to the bytes message stream as a 4-byte quantity, high byte first.

Parameters:

value - the float value to be written

Throws:

JMSException - if the JMS provider fails to write the message due to some internal error.

MessageNotWriteableException - if the message is in read-only mode.

writeDouble

void writeDouble(double value)
          throws JMSException

Converts the double argument to a long using the doubleToLongBits method in class Double, and then writes that long value to the bytes message stream as an 8-byte quantity, high byte first.

Parameters:

value - the double value to be written

Throws:

JMSException - if the JMS provider fails to write the message due to some internal error.

MessageNotWriteableException - if the message is in read-only mode.

writeUTF

void writeUTF(String value)
       throws JMSException

Writes a string to the bytes message stream using UTF-8 encoding in a machine-independent manner.

For more information on the UTF-8 format, see "File System Safe UCS Transformation Format (FSS_UTF)", X/Open Preliminary Specification, X/Open Company Ltd., Document Number: P316. This information also appears in ISO/IEC 10646, Annex P.

Parameters:

value - the String value to be written

Throws:

JMSException - if the JMS provider fails to write the message due to some internal error.

MessageNotWriteableException - if the message is in read-only mode.

writeBytes

void writeBytes(byte[] value)
         throws JMSException

Writes a byte array to the bytes message stream.

Parameters:

value - the byte array to be written

Throws:

JMSException - if the JMS provider fails to write the message due to some internal error.

MessageNotWriteableException - if the message is in read-only mode.

writeBytes

void writeBytes(byte[] value,
                int offset,
                int length)
         throws JMSException

Writes a portion of a byte array to the bytes message stream.

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:

JMSException - if the JMS provider fails to write the message due to some internal error.

MessageNotWriteableException - if the message is in read-only mode.

writeObject

void writeObject(Object value)
          throws JMSException

Writes an object to the bytes message stream.

This method works only for the objectified primitive object types (Integer, Double, Long ...), String objects, and byte arrays.

Parameters:

value - the object in the Java programming language ("Java object") to be written; it must not be null

Throws:

JMSException - if the JMS provider fails to write the message due to some internal error.

MessageFormatException - if the object is of an invalid type.

MessageNotWriteableException - if the message is in read-only mode.

NullPointerException - if the parameter value is null.

reset

void reset()
    throws JMSException

Puts the message body in read-only mode and repositions the stream of bytes to the beginning.

Throws:

JMSException - if the JMS provider fails to reset the message due to some internal error.

MessageFormatException - if the message has an invalid format.