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StreamMessage.javaAPI DocGlassfish v2 API23363Fri May 04 22:36:16 BST 2007javax.jms

StreamMessage

public interface StreamMessage implements 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.

version
1.0 - 6 August 1998
author
Mark Hapner
author
Rich Burridge
see
javax.jms.Session#createStreamMessage()
see
javax.jms.BytesMessage
see
javax.jms.MapMessage
see
javax.jms.Message
see
javax.jms.ObjectMessage
see
javax.jms.TextMessage

Fields Summary
Constructors Summary
Methods Summary
public booleanreadBoolean()
Reads a boolean from the stream message.

return
the boolean value read
exception
JMSException if the JMS provider fails to read the message due to some internal error.
exception
MessageEOFException if unexpected end of message stream has been reached.
exception
MessageFormatException if this type conversion is invalid.
exception
MessageNotReadableException if the message is in write-only mode.

public bytereadByte()
Reads a byte value from the stream message.

return
the next byte from the stream message as a 8-bit byte
exception
JMSException if the JMS provider fails to read the message due to some internal error.
exception
MessageEOFException if unexpected end of message stream has been reached.
exception
MessageFormatException if this type conversion is invalid.
exception
MessageNotReadableException if the message is in write-only mode.

public intreadBytes(byte[] value)
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.

param
value the buffer into which the data is read
return
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
exception
JMSException if the JMS provider fails to read the message due to some internal error.
exception
MessageEOFException if unexpected end of message stream has been reached.
exception
MessageFormatException if this type conversion is invalid.
exception
MessageNotReadableException if the message is in write-only mode.
see
#readObject()

public charreadChar()
Reads a Unicode character value from the stream message.

return
a Unicode character from the stream message
exception
JMSException if the JMS provider fails to read the message due to some internal error.
exception
MessageEOFException if unexpected end of message stream has been reached.
exception
MessageFormatException if this type conversion is invalid
exception
MessageNotReadableException if the message is in write-only mode.

public doublereadDouble()
Reads a double from the stream message.

return
a double value from the stream message
exception
JMSException if the JMS provider fails to read the message due to some internal error.
exception
MessageEOFException if unexpected end of message stream has been reached.
exception
MessageFormatException if this type conversion is invalid.
exception
MessageNotReadableException if the message is in write-only mode.

public floatreadFloat()
Reads a float from the stream message.

return
a float value from the stream message
exception
JMSException if the JMS provider fails to read the message due to some internal error.
exception
MessageEOFException if unexpected end of message stream has been reached.
exception
MessageFormatException if this type conversion is invalid.
exception
MessageNotReadableException if the message is in write-only mode.

public intreadInt()
Reads a 32-bit integer from the stream message.

return
a 32-bit integer value from the stream message, interpreted as an int
exception
JMSException if the JMS provider fails to read the message due to some internal error.
exception
MessageEOFException if unexpected end of message stream has been reached.
exception
MessageFormatException if this type conversion is invalid.
exception
MessageNotReadableException if the message is in write-only mode.

public longreadLong()
Reads a 64-bit integer from the stream message.

return
a 64-bit integer value from the stream message, interpreted as a long
exception
JMSException if the JMS provider fails to read the message due to some internal error.
exception
MessageEOFException if unexpected end of message stream has been reached.
exception
MessageFormatException if this type conversion is invalid.
exception
MessageNotReadableException if the message is in write-only mode.

public java.lang.ObjectreadObject()
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.

return
a Java object from the stream message, in objectified format (for example, if the object was written as an int, an Integer is returned)
exception
JMSException if the JMS provider fails to read the message due to some internal error.
exception
MessageEOFException if unexpected end of message stream has been reached.
exception
MessageFormatException if this type conversion is invalid.
exception
MessageNotReadableException if the message is in write-only mode.
see
#readBytes(byte[] value)

public shortreadShort()
Reads a 16-bit integer from the stream message.

return
a 16-bit integer from the stream message
exception
JMSException if the JMS provider fails to read the message due to some internal error.
exception
MessageEOFException if unexpected end of message stream has been reached.
exception
MessageFormatException if this type conversion is invalid.
exception
MessageNotReadableException if the message is in write-only mode.

public java.lang.StringreadString()
Reads a String from the stream message.

return
a Unicode string from the stream message
exception
JMSException if the JMS provider fails to read the message due to some internal error.
exception
MessageEOFException if unexpected end of message stream has been reached.
exception
MessageFormatException if this type conversion is invalid.
exception
MessageNotReadableException if the message is in write-only mode.

public voidreset()
Puts the message body in read-only mode and repositions the stream to the beginning.

exception
JMSException if the JMS provider fails to reset the message due to some internal error.
exception
MessageFormatException if the message has an invalid format.

public voidwriteBoolean(boolean value)
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.

param
value the boolean value to be written
exception
JMSException if the JMS provider fails to write the message due to some internal error.
exception
MessageNotWriteableException if the message is in read-only mode.

public voidwriteByte(byte value)
Writes a byte to the stream message.

param
value the byte value to be written
exception
JMSException if the JMS provider fails to write the message due to some internal error.
exception
MessageNotWriteableException if the message is in read-only mode.

public voidwriteBytes(byte[] value)
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.

param
value the byte array value to be written
exception
JMSException if the JMS provider fails to write the message due to some internal error.
exception
MessageNotWriteableException if the message is in read-only mode.

public voidwriteBytes(byte[] value, int offset, int length)
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.

param
value the byte array value to be written
param
offset the initial offset within the byte array
param
length the number of bytes to use
exception
JMSException if the JMS provider fails to write the message due to some internal error.
exception
MessageNotWriteableException if the message is in read-only mode.

public voidwriteChar(char value)
Writes a char to the stream message.

param
value the char value to be written
exception
JMSException if the JMS provider fails to write the message due to some internal error.
exception
MessageNotWriteableException if the message is in read-only mode.

public voidwriteDouble(double value)
Writes a double to the stream message.

param
value the double value to be written
exception
JMSException if the JMS provider fails to write the message due to some internal error.
exception
MessageNotWriteableException if the message is in read-only mode.

public voidwriteFloat(float value)
Writes a float to the stream message.

param
value the float value to be written
exception
JMSException if the JMS provider fails to write the message due to some internal error.
exception
MessageNotWriteableException if the message is in read-only mode.

public voidwriteInt(int value)
Writes an int to the stream message.

param
value the int value to be written
exception
JMSException if the JMS provider fails to write the message due to some internal error.
exception
MessageNotWriteableException if the message is in read-only mode.

public voidwriteLong(long value)
Writes a long to the stream message.

param
value the long value to be written
exception
JMSException if the JMS provider fails to write the message due to some internal error.
exception
MessageNotWriteableException if the message is in read-only mode.

public voidwriteObject(java.lang.Object value)
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.

param
value the Java object to be written
exception
JMSException if the JMS provider fails to write the message due to some internal error.
exception
MessageFormatException if the object is invalid.
exception
MessageNotWriteableException if the message is in read-only mode.

public voidwriteShort(short value)
Writes a short to the stream message.

param
value the short value to be written
exception
JMSException if the JMS provider fails to write the message due to some internal error.
exception
MessageNotWriteableException if the message is in read-only mode.

public voidwriteString(java.lang.String value)
Writes a String to the stream message.

param
value the String value to be written
exception
JMSException if the JMS provider fails to write the message due to some internal error.
exception
MessageNotWriteableException if the message is in read-only mode.