Top Description Fields Methods
javax.jms

public Interface StreamMessage

extends Message

A StreamMessage object is used to send a stream of primitive types in the Java programming language. It is filled and read sequentially. It inherits from the Message interface and adds a stream message body. Its methods are based largely on those found in java.io.DataInputStream and java.io.DataOutputStream.

The primitive types can be read or written explicitly using methods for each type. They may also be read or written generically as objects. For instance, a call to StreamMessage.writeInt(6) is equivalent to StreamMessage.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 body 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.

StreamMessage objects support the following conversion table. The marked cases must be supported. The unmarked cases must throw a JMSException. The String-to-primitive conversions may throw a runtime exception if the primitive's valueOf() method does not accept it as a valid String representation of the primitive.

A value written as the row type can be read as the column type.

|        | boolean byte short char int long float double String byte[]
|----------------------------------------------------------------------
|boolean |    X                                            X
|byte    |          X     X         X   X                  X   
|short   |                X         X   X                  X   
|char    |                     X                           X
|int     |                          X   X                  X   
|long    |                              X                  X   
|float   |                                    X     X      X   
|double  |                                          X      X   
|String  |    X     X     X         X   X     X     X      X   
|byte[]  |                                                        X
|----------------------------------------------------------------------

Attempting to read a null value as a primitive type must be treated as calling the primitive's corresponding valueOf(String) conversion method with a null value. Since char does not support a String conversion, attempting to read a null value as a char must throw a NullPointerException.

Since
JMS 1.0
Version
JMS 2.0
See Also
javax.jms.Session#createStreamMessage(), javax.jms.BytesMessage, javax.jms.MapMessage, javax.jms.Message, javax.jms.ObjectMessage, javax.jms.TextMessage

Field Summary

Inherited from javax.jms.Message:
DEFAULT_DELIVERY_DELAYDEFAULT_DELIVERY_MODEDEFAULT_PRIORITYDEFAULT_TIME_TO_LIVE

Method Summary

Modifier and TypeMethod and Description
public boolean

Returns:

the boolean value read
readBoolean
()

Reads a boolean from the stream message.

public byte

Returns:

the next byte from the stream message as a 8-bit byte
readByte
()

Reads a byte value from the stream message.

public int

Returns:

the total number of bytes read into the buffer, or -1 if there is no more data because the end of the byte field has been reached
readBytes
(byte[]
the buffer into which the data is read
value
)

Reads a byte array field from the stream message into the specified byte[] object (the read buffer).

public char

Returns:

a Unicode character from the stream message
readChar
()

Reads a Unicode character value from the stream message.

public double

Returns:

a double value from the stream message
readDouble
()

Reads a double from the stream message.

public float

Returns:

a float value from the stream message
readFloat
()

Reads a float from the stream message.

public int

Returns:

a 32-bit integer value from the stream message, interpreted as an int
readInt
()

Reads a 32-bit integer from the stream message.

public long

Returns:

a 64-bit integer value from the stream message, interpreted as a long
readLong
()

Reads a 64-bit integer from the stream message.

public Object

Returns:

a Java object from the stream message, in objectified format (for example, if the object was written as an int, an Integer is returned)
readObject
()

Reads an object from the stream message.

public short

Returns:

a 16-bit integer from the stream message
readShort
()

Reads a 16-bit integer from the stream message.

public String

Returns:

a Unicode string from the stream message
readString
()

Reads a String from the stream message.

public void
reset()

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

public void
writeBoolean(boolean
the boolean value to be written
value
)

Writes a boolean to the stream message.

public void
writeByte(byte
the byte value to be written
value
)

Writes a byte to the stream message.

public void
writeBytes(byte[]
the byte array value to be written
value
)

Writes a byte array field to the stream message.

public void
writeBytes(byte[]
the byte array value to be written
value
,
int
the initial offset within the byte array
offset
,
int
the number of bytes to use
length
)

Writes a portion of a byte array as a byte array field to the stream message.

public void
writeChar(char
the char value to be written
value
)

Writes a char to the stream message.

public void
writeDouble(double
the double value to be written
value
)

Writes a double to the stream message.

public void
writeFloat(float
the float value to be written
value
)

Writes a float to the stream message.

public void
writeInt(int
the int value to be written
value
)

Writes an int to the stream message.

public void
writeLong(long
the long value to be written
value
)

Writes a long to the stream message.

public void
writeObject(Object
the Java object to be written
value
)

Writes an object to the stream message.

public void
writeShort(short
the short value to be written
value
)

Writes a short to the stream message.

public void
writeString(String
the String value to be written
value
)

Writes a String to the stream message.

Inherited from javax.jms.Message:
acknowledgeclearBodyclearPropertiesgetBodygetBooleanPropertygetBytePropertygetDoublePropertygetFloatPropertygetIntPropertygetJMSCorrelationIDgetJMSCorrelationIDAsBytesgetJMSDeliveryModegetJMSDeliveryTimegetJMSDestinationgetJMSExpirationgetJMSMessageIDgetJMSPrioritygetJMSRedeliveredgetJMSReplyTogetJMSTimestampgetJMSTypegetLongPropertygetObjectPropertygetPropertyNamesgetShortPropertygetStringPropertyisBodyAssignableTopropertyExistssetBooleanPropertysetBytePropertysetDoublePropertysetFloatPropertysetIntPropertysetJMSCorrelationIDsetJMSCorrelationIDAsBytessetJMSDeliveryModesetJMSDeliveryTimesetJMSDestinationsetJMSExpirationsetJMSMessageIDsetJMSPrioritysetJMSRedeliveredsetJMSReplyTosetJMSTimestampsetJMSTypesetLongPropertysetObjectPropertysetShortPropertysetStringProperty

Method Detail

readBooleanback to summary
public boolean readBoolean() throws JMSException

Reads a boolean from the stream message.

Returns:boolean

the boolean value read

Exceptions
JMSException:
if the JMS provider fails to read the message due to some internal error.
MessageEOFException:
if unexpected end of message stream has been reached.
MessageFormatException:
if this type conversion is invalid.
MessageNotReadableException:
if the message is in write-only mode.
readByteback to summary
public byte readByte() throws JMSException

Reads a byte value from the stream message.

Returns:byte

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

Exceptions
JMSException:
if the JMS provider fails to read the message due to some internal error.
MessageEOFException:
if unexpected end of message stream has been reached.
MessageFormatException:
if this type conversion is invalid.
MessageNotReadableException:
if the message is in write-only mode.
readBytesback to summary
public int readBytes(byte[] value) throws JMSException

Reads a byte array field from the stream message into the specified byte[] object (the read buffer).

To read the field value, readBytes should be successively called until it returns a value less than the length of the read buffer. The value of the bytes in the buffer following the last byte read is undefined.

If readBytes returns a value equal to the length of the buffer, a subsequent readBytes call must be made. If there are no more bytes to be read, this call returns -1.

If the byte array field value is null, readBytes returns -1.

If the byte array field value is empty, readBytes returns 0.

Once the first readBytes call on a byte[] field value has been made, the full value of the field must be read before it is valid to read the next field. An attempt to read the next field before that has been done will throw a MessageFormatException.

To read the byte field value into a new byte[] object, use the readObject method.

Parameters
value:byte[]

the buffer into which the data is read

Returns:int

the total number of bytes read into the buffer, or -1 if there is no more data because the end of the byte field has been reached

Exceptions
JMSException:
if the JMS provider fails to read the message due to some internal error.
MessageEOFException:
if unexpected end of message stream has been reached.
MessageFormatException:
if this type conversion is invalid.
MessageNotReadableException:
if the message is in write-only mode.
See Also
readObject()
readCharback to summary
public char readChar() throws JMSException

Reads a Unicode character value from the stream message.

Returns:char

a Unicode character from the stream message

Exceptions
JMSException:
if the JMS provider fails to read the message due to some internal error.
MessageEOFException:
if unexpected end of message stream has been reached.
MessageFormatException:
if this type conversion is invalid
MessageNotReadableException:
if the message is in write-only mode.
readDoubleback to summary
public double readDouble() throws JMSException

Reads a double from the stream message.

Returns:double

a double value from the stream message

Exceptions
JMSException:
if the JMS provider fails to read the message due to some internal error.
MessageEOFException:
if unexpected end of message stream has been reached.
MessageFormatException:
if this type conversion is invalid.
MessageNotReadableException:
if the message is in write-only mode.
readFloatback to summary
public float readFloat() throws JMSException

Reads a float from the stream message.

Returns:float

a float value from the stream message

Exceptions
JMSException:
if the JMS provider fails to read the message due to some internal error.
MessageEOFException:
if unexpected end of message stream has been reached.
MessageFormatException:
if this type conversion is invalid.
MessageNotReadableException:
if the message is in write-only mode.
readIntback to summary
public int readInt() throws JMSException

Reads a 32-bit integer from the stream message.

Returns:int

a 32-bit integer value from the stream message, interpreted as an int

Exceptions
JMSException:
if the JMS provider fails to read the message due to some internal error.
MessageEOFException:
if unexpected end of message stream has been reached.
MessageFormatException:
if this type conversion is invalid.
MessageNotReadableException:
if the message is in write-only mode.
readLongback to summary
public long readLong() throws JMSException

Reads a 64-bit integer from the stream message.

Returns:long

a 64-bit integer value from the stream message, interpreted as a long

Exceptions
JMSException:
if the JMS provider fails to read the message due to some internal error.
MessageEOFException:
if unexpected end of message stream has been reached.
MessageFormatException:
if this type conversion is invalid.
MessageNotReadableException:
if the message is in write-only mode.
readObjectback to summary
public Object readObject() throws JMSException

Reads an object from the stream message.

This method can be used to return, in objectified format, an object in the Java programming language ("Java object") that has been written to the stream with the equivalent writeObject method call, or its equivalent primitive writetype method.

Note that byte values are returned as byte[], not Byte[].

An attempt to call readObject to read a byte field value into a new byte[] object before the full value of the byte field has been read will throw a MessageFormatException.

Returns:Object

a Java object from the stream message, in objectified format (for example, if the object was written as an int, an Integer is returned)

Exceptions
JMSException:
if the JMS provider fails to read the message due to some internal error.
MessageEOFException:
if unexpected end of message stream has been reached.
MessageFormatException:
if this type conversion is invalid.
MessageNotReadableException:
if the message is in write-only mode.
See Also
readBytes(byte[] value)
readShortback to summary
public short readShort() throws JMSException

Reads a 16-bit integer from the stream message.

Returns:short

a 16-bit integer from the stream message

Exceptions
JMSException:
if the JMS provider fails to read the message due to some internal error.
MessageEOFException:
if unexpected end of message stream has been reached.
MessageFormatException:
if this type conversion is invalid.
MessageNotReadableException:
if the message is in write-only mode.
readStringback to summary
public String readString() throws JMSException

Reads a String from the stream message.

Returns:String

a Unicode string from the stream message

Exceptions
JMSException:
if the JMS provider fails to read the message due to some internal error.
MessageEOFException:
if unexpected end of message stream has been reached.
MessageFormatException:
if this type conversion is invalid.
MessageNotReadableException:
if the message is in write-only mode.
resetback to summary
public void reset() throws JMSException

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

Exceptions
JMSException:
if the JMS provider fails to reset the message due to some internal error.
MessageFormatException:
if the message has an invalid format.
writeBooleanback to summary
public void writeBoolean(boolean value) throws JMSException

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

Parameters
value:boolean

the boolean value to be written

Exceptions
JMSException:
if the JMS provider fails to write the message due to some internal error.
MessageNotWriteableException:
if the message is in read-only mode.
writeByteback to summary
public void writeByte(byte value) throws JMSException

Writes a byte to the stream message.

Parameters
value:byte

the byte value to be written

Exceptions
JMSException:
if the JMS provider fails to write the message due to some internal error.
MessageNotWriteableException:
if the message is in read-only mode.
writeBytesback to summary
public void writeBytes(byte[] value) throws JMSException

Writes a byte array field to the stream message.

The byte array value is written to the message as a byte array field. Consecutively written byte array fields are treated as two distinct fields when the fields are read.

Parameters
value:byte[]

the byte array value to be written

Exceptions
JMSException:
if the JMS provider fails to write the message due to some internal error.
MessageNotWriteableException:
if the message is in read-only mode.
writeBytesback to summary
public void writeBytes(byte[] value, int offset, int length) throws JMSException

Writes a portion of a byte array as a byte array field to the stream message.

The a portion of the byte array value is written to the message as a byte array field. Consecutively written byte array fields are treated as two distinct fields when the fields are read.

Parameters
value:byte[]

the byte array value to be written

offset:int

the initial offset within the byte array

length:int

the number of bytes to use

Exceptions
JMSException:
if the JMS provider fails to write the message due to some internal error.
MessageNotWriteableException:
if the message is in read-only mode.
writeCharback to summary
public void writeChar(char value) throws JMSException

Writes a char to the stream message.

Parameters
value:char

the char value to be written

Exceptions
JMSException:
if the JMS provider fails to write the message due to some internal error.
MessageNotWriteableException:
if the message is in read-only mode.
writeDoubleback to summary
public void writeDouble(double value) throws JMSException

Writes a double to the stream message.

Parameters
value:double

the double value to be written

Exceptions
JMSException:
if the JMS provider fails to write the message due to some internal error.
MessageNotWriteableException:
if the message is in read-only mode.
writeFloatback to summary
public void writeFloat(float value) throws JMSException

Writes a float to the stream message.

Parameters
value:float

the float value to be written

Exceptions
JMSException:
if the JMS provider fails to write the message due to some internal error.
MessageNotWriteableException:
if the message is in read-only mode.
writeIntback to summary
public void writeInt(int value) throws JMSException

Writes an int to the stream message.

Parameters
value:int

the int value to be written

Exceptions
JMSException:
if the JMS provider fails to write the message due to some internal error.
MessageNotWriteableException:
if the message is in read-only mode.
writeLongback to summary
public void writeLong(long value) throws JMSException

Writes a long to the stream message.

Parameters
value:long

the long value to be written

Exceptions
JMSException:
if the JMS provider fails to write the message due to some internal error.
MessageNotWriteableException:
if the message is in read-only mode.
writeObjectback to summary
public void writeObject(Object value) throws JMSException

Writes an object to the stream message.

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

Parameters
value:Object

the Java object to be written

Exceptions
JMSException:
if the JMS provider fails to write the message due to some internal error.
MessageFormatException:
if the object is invalid.
MessageNotWriteableException:
if the message is in read-only mode.
writeShortback to summary
public void writeShort(short value) throws JMSException

Writes a short to the stream message.

Parameters
value:short

the short value to be written

Exceptions
JMSException:
if the JMS provider fails to write the message due to some internal error.
MessageNotWriteableException:
if the message is in read-only mode.
writeStringback to summary
public void writeString(String value) throws JMSException

Writes a String to the stream message.

Parameters
value:String

the String value to be written

Exceptions
JMSException:
if the JMS provider fails to write the message due to some internal error.
MessageNotWriteableException:
if the message is in read-only mode.