AStreamMessage
object is used to send a stream of primitive types in the Java programming language. It is filled and read sequentially. It inherits from theMessage
interface and adds a stream message body. Its methods are based largely on those found injava.io.DataInputStream
andjava.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 toStreamMessage.writeInt(6)
is equivalent toStreamMessage.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 whenclearBody
is called, the body of the message is in write-only mode. After the first call toreset
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 calledreset
so that the message body is in read-only mode for the client.
IfclearBody
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, aMessageNotReadableException
is thrown.
If a client attempts to write a message in read-only mode, aMessageNotWriteableException
is thrown.
StreamMessage
objects support the following conversion table. The marked cases must be supported. The unmarked cases must throw aJMSException
. TheString
-to-primitive conversions may throw a runtime exception if the primitive'svalueOf()
method does not accept it as a validString
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 correspondingvalueOf(String)
conversion method with a null value. Sincechar
does not support aString
conversion, attempting to read a null value as achar
must throw aNullPointerException
.
Session.createStreamMessage()
,BytesMessage
,MapMessage
,Message
,ObjectMessage
,TextMessage
Fields inherited from interface javax.jms.Message |
DEFAULT_DELIVERY_MODE,DEFAULT_PRIORITY,DEFAULT_TIME_TO_LIVE |
readBoolean() Reads a boolean from the stream message. | |
readByte() Reads a byte value from the stream message. | |
readBytes(byte[] value) Reads a byte array field from the stream message into the specified byte[] object (the read buffer). | |
readChar() Reads a Unicode character value from the stream message. | |
readDouble() Reads a double from the stream message. | |
readFloat() Reads a float from the stream message. | |
readInt() Reads a 32-bit integer from the stream message. | |
readLong() Reads a 64-bit integer from the stream message. | |
readObject() Reads an object from the stream message. | |
readShort() Reads a 16-bit integer from the stream message. | |
readString() Reads a String from the stream message. | |
reset() Puts the message body in read-only mode and repositions the stream to the beginning. | |
writeBoolean(boolean value) Writes a boolean to the stream message. | |
writeByte(byte value) Writes a byte to the stream message. | |
writeBytes(byte[] value) Writes a byte array field to the stream message. | |
writeBytes(byte[] value, int offset, int length) Writes a portion of a byte array as a byte array field to the stream message. | |
writeChar(char value) Writes a char to the stream message. | |
writeDouble(double value) Writes a double to the stream message. | |
writeFloat(float value) Writes a float to the stream message. | |
writeInt(int value) Writes an int to the stream message. | |
writeLong(long value) Writes a long to the stream message. | |
writeObject(java.lang.Object value) Writes an object to the stream message. | |
writeShort(short value) Writes a short to the stream message. | |
writeString(java.lang.String value) Writes a String to the stream message. |
public booleanreadBoolean() throwsJMSException
boolean
from the stream message.boolean
value readJMSException
- 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.public bytereadByte() throwsJMSException
byte
value from the stream message.byte
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.public shortreadShort() throwsJMSException
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.public charreadChar() throwsJMSException
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 invalidMessageNotReadableException
- if the message is in write-only mode.public intreadInt() throwsJMSException
int
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.public longreadLong() throwsJMSException
long
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.public floatreadFloat() throwsJMSException
float
from the stream message.float
value from the stream messageJMSException
- 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.public doublereadDouble() throwsJMSException
double
from the stream message.double
value from the stream messageJMSException
- 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.public java.lang.StringreadString() throwsJMSException
String
from the stream message.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.public intreadBytes(byte[] value) throwsJMSException
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.
IfreadBytes
returns a value equal to the length of the buffer, a subsequentreadBytes
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 firstreadBytes
call on abyte[]
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 aMessageFormatException
.
To read the byte field value into a newbyte[]
object, use thereadObject
method.
value
- the buffer into which the data is readJMSException
- 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.readObject()
public java.lang.ObjectreadObject() throwsJMSException
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 equivalentwriteObject
method call, or its equivalent primitivewritetype
method.
Note that byte values are returned asbyte[]
, notByte[]
.
An attempt to callreadObject
to read a byte field value into a newbyte[]
object before the full value of the byte field has been read will throw aMessageFormatException
.
int
, anInteger
is returned)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.readBytes(byte[] value)
public voidwriteBoolean(boolean value) throwsJMSException
boolean
to the stream message. The valuetrue
is written as the value(byte)1
; the valuefalse
is written as the value(byte)0
.value
- theboolean
value to be writtenJMSException
- if the JMS provider fails to write the message due to some internal error.MessageNotWriteableException
- if the message is in read-only mode.public voidwriteByte(byte value) throwsJMSException
byte
to the stream message.value
- thebyte
value to be writtenJMSException
- if the JMS provider fails to write the message due to some internal error.MessageNotWriteableException
- if the message is in read-only mode.public voidwriteShort(short value) throwsJMSException
short
to the stream message.value
- theshort
value to be writtenJMSException
- if the JMS provider fails to write the message due to some internal error.MessageNotWriteableException
- if the message is in read-only mode.public voidwriteChar(char value) throwsJMSException
char
to the stream message.value
- thechar
value to be writtenJMSException
- if the JMS provider fails to write the message due to some internal error.MessageNotWriteableException
- if the message is in read-only mode.public voidwriteInt(int value) throwsJMSException
int
to the stream message.value
- theint
value to be writtenJMSException
- if the JMS provider fails to write the message due to some internal error.MessageNotWriteableException
- if the message is in read-only mode.public voidwriteLong(long value) throwsJMSException
long
to the stream message.value
- thelong
value to be writtenJMSException
- if the JMS provider fails to write the message due to some internal error.MessageNotWriteableException
- if the message is in read-only mode.public voidwriteFloat(float value) throwsJMSException
float
to the stream message.value
- thefloat
value to be writtenJMSException
- if the JMS provider fails to write the message due to some internal error.MessageNotWriteableException
- if the message is in read-only mode.public voidwriteDouble(double value) throwsJMSException
double
to the stream message.value
- thedouble
value to be writtenJMSException
- if the JMS provider fails to write the message due to some internal error.MessageNotWriteableException
- if the message is in read-only mode.public voidwriteString(java.lang.String value) throwsJMSException
String
to the stream message.value
- theString
value to be writtenJMSException
- if the JMS provider fails to write the message due to some internal error.MessageNotWriteableException
- if the message is in read-only mode.public voidwriteBytes(byte[] value) throwsJMSException
The byte arrayvalue
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.
value
- the byte array value to be writtenJMSException
- if the JMS provider fails to write the message due to some internal error.MessageNotWriteableException
- if the message is in read-only mode.public voidwriteBytes(byte[] value, int offset, int length) throwsJMSException
The a portion of the byte arrayvalue
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.
value
- the byte array value to be writtenoffset
- the initial offset within the byte arraylength
- the number of bytes to useJMSException
- if the JMS provider fails to write the message due to some internal error.MessageNotWriteableException
- if the message is in read-only mode.public voidwriteObject(java.lang.Object value) throwsJMSException
This method works only for the objectified primitive object types (Integer
,Double
,Long
...),String
objects, and byte arrays.
value
- the Java object to be writtenJMSException
- 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.public voidreset() throwsJMSException
JMSException
- if the JMS provider fails to reset the message due to some internal error.MessageFormatException
- if the message has an invalid format.