public interface Message
The Message
interface is the root interface of all JMS
messages. It defines the message header and the acknowledge
method used for all messages.
Most message-oriented middleware (MOM) products treat messages as lightweight entities that consist of a header and a payload. The header contains fields used for message routing and identification; the payload contains the application data being sent.
Within this general form, the definition of a message varies significantly across products. It would be quite difficult for the JMS API to support all of these message models.
With this in mind, the JMS message model has the following goals:
JMS messages are composed of the following parts:
The JMS API defines five types of message body:
StreamMessage
object's message body contains
a stream of primitive values in the Java programming
language ("Java primitives"). It is filled and read sequentially.
MapMessage
object's message body contains a set
of name-value pairs, where names are String
objects, and values are Java primitives. The entries can be accessed
sequentially or randomly by name. The order of the entries is
undefined.
TextMessage
object's message body contains a
java.lang.String
object. This message type can be used
to transport plain-text messages, and XML messages.
ObjectMessage
object's message body contains
a Serializable
Java object.
BytesMessage
object's message body contains a
stream of uninterpreted bytes. This message type is for
literally encoding a body to match an existing message format. In
many cases, it is possible to use one of the other body types,
which are easier to use. 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 JMSCorrelationID
header field is used for linking one
message with
another. It typically links a reply message with its requesting message.
JMSCorrelationID
can hold a provider-specific message ID,
an application-specific String
object, or a provider-native
byte[]
value.
A Message
object contains a built-in facility for supporting
application-defined property values. In effect, this provides a mechanism
for adding application-specific header fields to a message.
Properties allow an application, via message selectors, to have a JMS provider select, or filter, messages on its behalf using application-specific criteria.
Property names must obey the rules for a message selector identifier.
Property names must not be null, and must not be empty strings. If a property
name is set and it is either null or an empty string, an
IllegalArgumentException
must be thrown.
Property values can be boolean
, byte
,
short
, int
, long
, float
,
double
, and String
.
Property values are set prior to sending a message. When a client
receives a message, its properties are in read-only mode. If a
client attempts to set properties at this point, a
MessageNotWriteableException
is thrown. If
clearProperties
is called, the properties can now be both
read from and written to. Note that header fields are distinct from
properties. Header fields are never in read-only mode.
A property value may duplicate a value in a message's body, or it may not. Although JMS does not define a policy for what should or should not be made a property, application developers should note that JMS providers will likely handle data in a message's body more efficiently than data in a message's properties. For best performance, applications should use message properties only when they need to customize a message's header. The primary reason for doing this is to support customized message selection.
Message properties 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 the
String
as a valid representation of the primitive.
A value written as the row type can be read as the column type.
| | boolean byte short int long float double String |---------------------------------------------------------- |boolean | X X |byte | X X X X X |short | X X 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 |----------------------------------------------------------
In addition to the type-specific set/get methods for properties, JMS
provides the setObjectProperty
and
getObjectProperty
methods. These support the same set of
property types using the objectified primitive values. Their purpose is
to allow the decision of property type to made at execution time rather
than at compile time. They support the same property value conversions.
The setObjectProperty
method accepts values of class
Boolean
, Byte
, Short
,
Integer
, Long
, Float
,
Double
, and String
. An attempt
to use any other class must throw a JMSException
.
The getObjectProperty
method only returns values of class
Boolean
, Byte
, Short
,
Integer
, Long
, Float
,
Double
, and String
.
The order of property values is not defined. To iterate through a
message's property values, use getPropertyNames
to retrieve
a property name enumeration and then use the various property get methods
to retrieve their values.
A message's properties are deleted by the clearProperties
method. This leaves the message with an empty set of properties.
Getting a property value for a name which has not been set returns a
null value. Only the getStringProperty
and
getObjectProperty
methods can return a null value.
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.
The JMS API reserves the JMSX
property name prefix for JMS
defined properties.
The full set of these properties is defined in the Java Message Service
specification. New JMS defined properties may be added in later versions
of the JMS API. Support for these properties is optional. The
String[] ConnectionMetaData.getJMSXPropertyNames
method
returns the names of the JMSX properties supported by a connection.
JMSX properties may be referenced in message selectors whether or not they are supported by a connection. If they are not present in a message, they are treated like any other absent property.
JMSX properties defined in the specification as "set by provider on send" are available to both the producer and the consumers of the message. JMSX properties defined in the specification as "set by provider on receive" are available only to the consumers.
JMSXGroupID
and JMSXGroupSeq
are standard
properties that clients
should use if they want to group messages. All providers must support them.
Unless specifically noted, the values and semantics of the JMSX properties
are undefined.
The JMS API reserves the JMS_vendor_name
property
name prefix for provider-specific properties. Each provider defines its own
value for vendor_name
. This is the mechanism a JMS
provider uses to make its special per-message services available to a JMS
client.
The purpose of provider-specific properties is to provide special features needed to integrate JMS clients with provider-native clients in a single JMS application. They should not be used for messaging between JMS clients.
The JMS API provides a set of message interfaces that define the JMS message model. It does not provide implementations of these interfaces.
Each JMS provider supplies a set of message factories with its
Session
object for creating instances of messages. This allows
a provider to use message implementations tailored to its specific needs.
A provider must be prepared to accept message implementations that are not its own. They may not be handled as efficiently as its own implementation; however, they must be handled.
Note the following exception case when a provider is handling a foreign
message implementation. If the foreign message implementation contains a
JMSReplyTo
header field that is set to a foreign destination
implementation, the provider is not required to handle or preserve the
value of this header field.
A JMS message selector allows a client to specify, by
header field references and property references, the
messages it is interested in. Only messages whose header
and property values
match the
selector are delivered. What it means for a message not to be delivered
depends on the MessageConsumer
being used (see
QueueReceiver
and
TopicSubscriber
).
Message selectors cannot reference message body values.
A message selector matches a message if the selector evaluates to true when the message's header field values and property values are substituted for their corresponding identifiers in the selector.
A message selector is a String
whose syntax is based on a
subset of
the SQL92 conditional expression syntax. If the value of a message selector
is an empty string, the value is treated as a null and indicates that there
is no message selector for the message consumer.
The order of evaluation of a message selector is from left to right within precedence level. Parentheses can be used to change this order.
Predefined selector literals and operator names are shown here in uppercase; however, they are case insensitive.
A selector can contain:
'literal'
and 'literal''s'
. Like
string literals in the Java programming language, these use the
Unicode character encoding.
57
, -957
, and
+62
; numbers in the range of long
are
supported. Exact numeric literals use the integer literal
syntax of the Java programming language.
7E3
and -57.9E2
, or a
numeric value with a decimal, such as 7.
,
-95.7
, and +6.2
; numbers in the range of
double
are supported. Approximate literals use the
floating-point literal syntax of the Java programming language.
TRUE
and FALSE
.
Character.isJavaLetter
returns true. This includes '_'
and '$'
.
A letter or digit is any character for which the method
Character.isJavaLetterOrDigit
returns true.
NULL
,
TRUE
, and FALSE
.
NOT
, AND
,
OR
, BETWEEN
, LIKE
,
IN
, IS
, or ESCAPE
.
NULL
.
myMessage.setStringProperty("NumberOfOrders", "2");The following expression in a message selector would evaluate to false, because a string cannot be used in an arithmetic expression:
"NumberOfOrders > 1"
JMSDeliveryMode
, JMSPriority
,
JMSMessageID
, JMSTimestamp
,
JMSCorrelationID
, and JMSType
.
JMSMessageID
, JMSCorrelationID
, and
JMSType
values may be null and if so are treated as a
NULL
value.
'JMSX'
is a JMS defined
property name.
'JMS_'
is a provider-specific
property name.
'JMS'
is an
application-specific property name.
true
matches; a selector that evaluates to
false
or unknown does not match.
()
for ordering expression evaluation
is supported.
NOT
,
AND
, OR
=
, >
, >=
,
<</CODE>, <=< /code="/code">,
(not equal)
- Only like type values can be compared. One exception is that it
is valid to compare exact numeric values and approximate numeric
values; the type conversion required is defined by the rules of
numeric promotion in the Java programming language. If the
comparison of non-like type values is attempted, the value of the
operation is false. If either of the type values evaluates to
NULL
, the value of the expression is unknown.
- String and boolean comparison is restricted to
=
and
. Two strings are equal
if and only if they contain the same sequence of characters.
- Arithmetic operators in precedence order:
+
, -
(unary)
*
, /
(multiplication and division)
+
, -
(addition and subtraction)
- Arithmetic operations must use numeric promotion in the Java
programming language.
arithmetic-expr1 [NOT] BETWEEN arithmetic-expr2
AND arithmetic-expr3
(comparison operator)
"age BETWEEN 15 AND 19"
is
equivalent to
"age >= 15 AND age <= 19"< /code="/code">
"age NOT BETWEEN 15 AND 19"
is equivalent to
"age < 15 or age > 19"
identifier [NOT] IN (string-literal1,
string-literal2,...)
(comparison operator where
identifier
has a String
or
NULL
value)
"Country IN (' UK', 'US', 'France')"
is true for
'UK'
and false for 'Peru'
; it is
equivalent to the expression
"(Country = ' UK') OR (Country = ' US') OR (Country = ' France')"
"Country NOT IN (' UK', 'US', 'France')"
is false for 'UK'
and true for 'Peru'
; it
is equivalent to the expression
"NOT ((Country = ' UK') OR (Country = ' US') OR (Country = ' France'))"
- If identifier of an
IN
or NOT IN
operation is NULL
, the value of the operation is
unknown.
identifier [NOT] LIKE pattern-value [ESCAPE
escape-character]
(comparison operator, where
identifier
has a String
value;
pattern-value
is a string literal where
'_'
stands for any single character; '%'
stands for any sequence of characters, including the empty sequence;
and all other characters stand for themselves. The optional
escape-character
is a single-character string
literal whose character is used to escape the special meaning of the
'_'
and '%'
in
pattern-value
.)
"phone LIKE '12%3'"
is true for
'123'
or '12993'
and false for
'1234'
"word LIKE 'l_se'"
is true for
'lose'
and false for 'loose'
"underscored LIKE '\_%' ESCAPE '\'"
is true for '_foo'
and false for 'bar'
"phone NOT LIKE '12%3'"
is false for
'123'
or '12993'
and true for
'1234'
- If
identifier
of a LIKE
or
NOT LIKE
operation is NULL
, the value
of the operation is unknown.
identifier IS NULL
(comparison operator that tests
for a null header field value or a missing property value)
"prop_name IS NULL"
identifier IS NOT NULL
(comparison operator that
tests for the existence of a non-null header field value or a property
value)
"prop_name IS NOT NULL"
JMS providers are required to verify the syntactic correctness of a
message selector at the time it is presented. A method that provides a
syntactically incorrect selector must result in a JMSException
.
JMS providers may also optionally provide some semantic checking at the time
the selector is presented. Not all semantic checking can be performed at
the time a message selector is presented, because property types are not known.
The following message selector selects messages with a message type
of car and color of blue and weight greater than 2500 pounds:
"JMSType = 'car' AND color = 'blue' AND weight > 2500"
Null Values
As noted above, property values may be NULL
. The evaluation
of selector expressions containing NULL
values is defined by
SQL92 NULL
semantics. A brief description of these semantics
is provided here.
SQL treats a NULL
value as unknown. Comparison or arithmetic
with an unknown value always yields an unknown value.
The IS NULL
and IS NOT NULL
operators convert
an unknown value into the respective TRUE
and
FALSE
values.
The boolean operators use three-valued logic as defined by the
following tables:
The definition of the AND
operator
| AND | T | F | U
+------+-------+-------+-------
| T | T | F | U
| F | F | F | F
| U | U | F | U
+------+-------+-------+-------
The definition of the OR
operator
| OR | T | F | U
+------+-------+-------+--------
| T | T | T | T
| F | T | F | U
| U | T | U | U
+------+-------+-------+-------
The definition of the NOT
operator
| NOT
+------+------
| T | F
| F | T
| U | U
+------+-------
Special Notes
When used in a message selector, the JMSDeliveryMode
header
field is treated as having the values 'PERSISTENT'
and
'NON_PERSISTENT'
.
Date and time values should use the standard long
millisecond value. When a date or time literal is included in a message
selector, it should be an integer literal for a millisecond value. The
standard way to produce millisecond values is to use
java.util.Calendar
.
Although SQL supports fixed decimal comparison and arithmetic, JMS
message selectors do not. This is the reason for restricting exact
numeric literals to those without a decimal (and the addition of
numerics with a decimal as an alternate representation for
approximate numeric values).
SQL comments are not supported.
- See Also:
MessageConsumer.receive()
,
MessageConsumer.receive(long)
,
MessageConsumer.receiveNoWait()
,
MessageListener.onMessage(Message)
,
BytesMessage
,
MapMessage
,
ObjectMessage
,
StreamMessage
,
TextMessage
Field Summary
static int
DEFAULT_DELIVERY_MODE
The message producer's default delivery mode is PERSISTENT
.
static int
DEFAULT_PRIORITY
The message producer's default priority is 4.
static long
DEFAULT_TIME_TO_LIVE
The message producer's default time to live is unlimited; the message
never expires.
Method Summary
void
acknowledge()
Acknowledges all consumed messages of the session of this consumed
message.
void
clearBody()
Clears out the message body.
void
clearProperties()
Clears a message's properties.
boolean
getBooleanProperty(java.lang.String name)
Returns the value of the boolean
property with the
specified name.
byte
getByteProperty(java.lang.String name)
Returns the value of the byte
property with the specified
name.
double
getDoubleProperty(java.lang.String name)
Returns the value of the double
property with the specified
name.
float
getFloatProperty(java.lang.String name)
Returns the value of the float
property with the specified
name.
int
getIntProperty(java.lang.String name)
Returns the value of the int
property with the specified
name.
java.lang.String
getJMSCorrelationID()
Gets the correlation ID for the message.
byte[]
getJMSCorrelationIDAsBytes()
Gets the correlation ID as an array of bytes for the message.
int
getJMSDeliveryMode()
Gets the DeliveryMode
value specified for this message.
Destination
getJMSDestination()
Gets the Destination
object for this message.
long
getJMSExpiration()
Gets the message's expiration value.
java.lang.String
getJMSMessageID()
Gets the message ID.
int
getJMSPriority()
Gets the message priority level.
boolean
getJMSRedelivered()
Gets an indication of whether this message is being redelivered.
Destination
getJMSReplyTo()
Gets the Destination
object to which a reply to this
message should be sent.
long
getJMSTimestamp()
Gets the message timestamp.
java.lang.String
getJMSType()
Gets the message type identifier supplied by the client when the
message was sent.
long
getLongProperty(java.lang.String name)
Returns the value of the long
property with the specified
name.
java.lang.Object
getObjectProperty(java.lang.String name)
Returns the value of the Java object property with the specified name.
java.util.Enumeration
getPropertyNames()
Returns an Enumeration
of all the property names.
short
getShortProperty(java.lang.String name)
Returns the value of the short
property with the specified
name.
java.lang.String
getStringProperty(java.lang.String name)
Returns the value of the String
property with the specified
name.
boolean
propertyExists(java.lang.String name)
Indicates whether a property value exists.
void
setBooleanProperty(java.lang.String name,
boolean value)
Sets a boolean
property value with the specified name into
the message.
void
setByteProperty(java.lang.String name,
byte value)
Sets a byte
property value with the specified name into
the message.
void
setDoubleProperty(java.lang.String name,
double value)
Sets a double
property value with the specified name into
the message.
void
setFloatProperty(java.lang.String name,
float value)
Sets a float
property value with the specified name into
the message.
void
setIntProperty(java.lang.String name,
int value)
Sets an int
property value with the specified name into
the message.
void
setJMSCorrelationID(java.lang.String correlationID)
Sets the correlation ID for the message.
void
setJMSCorrelationIDAsBytes(byte[] correlationID)
Sets the correlation ID as an array of bytes for the message.
void
setJMSDeliveryMode(int deliveryMode)
Sets the DeliveryMode
value for this message.
void
setJMSDestination(Destination destination)
Sets the Destination
object for this message.
void
setJMSExpiration(long expiration)
Sets the message's expiration value.
void
setJMSMessageID(java.lang.String id)
Sets the message ID.
void
setJMSPriority(int priority)
Sets the priority level for this message.
void
setJMSRedelivered(boolean redelivered)
Specifies whether this message is being redelivered.
void
setJMSReplyTo(Destination replyTo)
Sets the Destination
object to which a reply to this
message should be sent.
void
setJMSTimestamp(long timestamp)
Sets the message timestamp.
void
setJMSType(java.lang.String type)
Sets the message type.
void
setLongProperty(java.lang.String name,
long value)
Sets a long
property value with the specified name into
the message.
void
setObjectProperty(java.lang.String name,
java.lang.Object value)
Sets a Java object property value with the specified name into the
message.
void
setShortProperty(java.lang.String name,
short value)
Sets a short
property value with the specified name into
the message.
void
setStringProperty(java.lang.String name,
java.lang.String value)
Sets a String
property value with the specified name into
the message.
Field Detail
DEFAULT_DELIVERY_MODE
static final int DEFAULT_DELIVERY_MODE
- The message producer's default delivery mode is
PERSISTENT
.
- See Also:
DeliveryMode#PERSISTENT
,
Constant Field Values
DEFAULT_PRIORITY
static final int DEFAULT_PRIORITY
- The message producer's default priority is 4.
- See Also:
- Constant Field Values
DEFAULT_TIME_TO_LIVE
static final long DEFAULT_TIME_TO_LIVE
- The message producer's default time to live is unlimited; the message
never expires.
- See Also:
- Constant Field Values
Method Detail
getJMSMessageID
java.lang.String getJMSMessageID()
throws JMSException
- Gets the message ID.
The JMSMessageID
header field contains a value that
uniquely identifies each message sent by a provider.
When a message is sent, JMSMessageID
can be ignored.
When the send
or publish
method returns, it
contains a provider-assigned value.
A JMSMessageID
is a String
value that
should function as a
unique key for identifying messages in a historical repository.
The exact scope of uniqueness is provider-defined. It should at
least cover all messages for a specific installation of a
provider, where an installation is some connected set of message
routers.
All JMSMessageID
values must start with the prefix
'ID:'
.
Uniqueness of message ID values across different providers is
not required.
Since message IDs take some effort to create and increase a
message's size, some JMS providers may be able to optimize message
overhead if they are given a hint that the message ID is not used by
an application. By calling the
MessageProducer.setDisableMessageID
method, a JMS client
enables this potential optimization for all messages sent by that
message producer. If the JMS provider accepts this
hint, these messages must have the message ID set to null; if the
provider ignores the hint, the message ID must be set to its normal
unique value.
- Returns:
- the message ID
- Throws:
JMSException
- if the JMS provider fails to get the message ID
due to some internal error.- See Also:
setJMSMessageID(String)
,
MessageProducer.setDisableMessageID(boolean)
setJMSMessageID
void setJMSMessageID(java.lang.String id)
throws JMSException
- Sets the message ID.
JMS providers set this field when a message is sent. This method
can be used to change the value for a message that has been received.
- Parameters:
id
- the ID of the message
- Throws:
JMSException
- if the JMS provider fails to set the message ID
due to some internal error.- See Also:
getJMSMessageID()
getJMSTimestamp
long getJMSTimestamp()
throws JMSException
- Gets the message timestamp.
The JMSTimestamp
header field contains the time a
message was
handed off to a provider to be sent. It is not the time the
message was actually transmitted, because the actual send may occur
later due to transactions or other client-side queueing of messages.
When a message is sent, JMSTimestamp
is ignored. When
the send
or publish
method returns, it contains a time value somewhere in the interval
between the call and the return. The value is in the format of a normal
millis time value in the Java programming language.
Since timestamps take some effort to create and increase a
message's size, some JMS providers may be able to optimize message
overhead if they are given a hint that the timestamp is not used by an
application. By calling the
MessageProducer.setDisableMessageTimestamp
method, a JMS
client enables this potential optimization for all messages sent by
that message producer. If the JMS provider accepts this
hint, these messages must have the timestamp set to zero; if the
provider ignores the hint, the timestamp must be set to its normal
value.
- Returns:
- the message timestamp
- Throws:
JMSException
- if the JMS provider fails to get the timestamp
due to some internal error.- See Also:
setJMSTimestamp(long)
,
MessageProducer.setDisableMessageTimestamp(boolean)
setJMSTimestamp
void setJMSTimestamp(long timestamp)
throws JMSException
- Sets the message timestamp.
JMS providers set this field when a message is sent. This method
can be used to change the value for a message that has been received.
- Parameters:
timestamp
- the timestamp for this message
- Throws:
JMSException
- if the JMS provider fails to set the timestamp
due to some internal error.- See Also:
getJMSTimestamp()
getJMSCorrelationIDAsBytes
byte[] getJMSCorrelationIDAsBytes()
throws JMSException
- Gets the correlation ID as an array of bytes for the message.
The use of a byte[]
value for
JMSCorrelationID
is non-portable.
- Returns:
- the correlation ID of a message as an array of bytes
- Throws:
JMSException
- if the JMS provider fails to get the correlation
ID due to some internal error.- See Also:
setJMSCorrelationID(String)
,
getJMSCorrelationID()
,
setJMSCorrelationIDAsBytes(byte[])
setJMSCorrelationIDAsBytes
void setJMSCorrelationIDAsBytes(byte[] correlationID)
throws JMSException
- Sets the correlation ID as an array of bytes for the message.
The array is copied before the method returns, so
future modifications to the array will not alter this message header.
If a provider supports the native concept of correlation ID, a
JMS client may need to assign specific JMSCorrelationID
values to match those expected by native messaging clients.
JMS providers without native correlation ID values are not required to
support this method and its corresponding get method; their
implementation may throw a
java.lang.UnsupportedOperationException
.
The use of a byte[]
value for
JMSCorrelationID
is non-portable.
- Parameters:
correlationID
- the correlation ID value as an array of bytes
- Throws:
JMSException
- if the JMS provider fails to set the correlation
ID due to some internal error.- See Also:
setJMSCorrelationID(String)
,
getJMSCorrelationID()
,
getJMSCorrelationIDAsBytes()
setJMSCorrelationID
void setJMSCorrelationID(java.lang.String correlationID)
throws JMSException
- Sets the correlation ID for the message.
A client can use the JMSCorrelationID
header field to
link one message with another. A typical use is to link a response
message with its request message.
JMSCorrelationID
can hold one of the following:
- A provider-specific message ID
- An application-specific
String
- A provider-native
byte[]
value
Since each message sent by a JMS provider is assigned a message ID
value, it is convenient to link messages via message ID. All message ID
values must start with the 'ID:'
prefix.
In some cases, an application (made up of several clients) needs to
use an application-specific value for linking messages. For instance,
an application may use JMSCorrelationID
to hold a value
referencing some external information. Application-specified values
must not start with the 'ID:'
prefix; this is reserved for
provider-generated message ID values.
If a provider supports the native concept of correlation ID, a JMS
client may need to assign specific JMSCorrelationID
values
to match those expected by clients that do not use the JMS API. A
byte[]
value is used for this
purpose. JMS providers without native correlation ID values are not
required to support byte[]
values. The use of a
byte[]
value for JMSCorrelationID
is
non-portable.
- Parameters:
correlationID
- the message ID of a message being referred to
- Throws:
JMSException
- if the JMS provider fails to set the correlation
ID due to some internal error.- See Also:
getJMSCorrelationID()
,
getJMSCorrelationIDAsBytes()
,
setJMSCorrelationIDAsBytes(byte[])
getJMSCorrelationID
java.lang.String getJMSCorrelationID()
throws JMSException
- Gets the correlation ID for the message.
This method is used to return correlation ID values that are
either provider-specific message IDs or application-specific
String
values.
- Returns:
- the correlation ID of a message as a
String
- Throws:
JMSException
- if the JMS provider fails to get the correlation
ID due to some internal error.- See Also:
setJMSCorrelationID(String)
,
getJMSCorrelationIDAsBytes()
,
setJMSCorrelationIDAsBytes(byte[])
getJMSReplyTo
Destination getJMSReplyTo()
throws JMSException
- Gets the
Destination
object to which a reply to this
message should be sent.
- Returns:
Destination
to which to send a response to this
message
- Throws:
JMSException
- if the JMS provider fails to get the
JMSReplyTo
destination due to some
internal error.- See Also:
setJMSReplyTo(Destination)
setJMSReplyTo
void setJMSReplyTo(Destination replyTo)
throws JMSException
- Sets the
Destination
object to which a reply to this
message should be sent.
The JMSReplyTo
header field contains the destination
where a reply
to the current message should be sent. If it is null, no reply is
expected. The destination may be either a Queue
object or
a Topic
object.
Messages sent with a null JMSReplyTo
value may be a
notification of some event, or they may just be some data the sender
thinks is of interest.
Messages with a JMSReplyTo
value typically expect a
response. A response is optional; it is up to the client to decide.
These messages are called requests. A message sent in response to a
request is called a reply.
In some cases a client may wish to match a request it sent earlier
with a reply it has just received. The client can use the
JMSCorrelationID
header field for this purpose.
- Parameters:
replyTo
- Destination
to which to send a response to
this message
- Throws:
JMSException
- if the JMS provider fails to set the
JMSReplyTo
destination due to some
internal error.- See Also:
getJMSReplyTo()
getJMSDestination
Destination getJMSDestination()
throws JMSException
- Gets the
Destination
object for this message.
The JMSDestination
header field contains the
destination to which the message is being sent.
When a message is sent, this field is ignored. After completion
of the send
or publish
method, the field
holds the destination specified by the method.
When a message is received, its JMSDestination
value
must be equivalent to the value assigned when it was sent.
- Returns:
- the destination of this message
- Throws:
JMSException
- if the JMS provider fails to get the destination
due to some internal error.- See Also:
setJMSDestination(Destination)
setJMSDestination
void setJMSDestination(Destination destination)
throws JMSException
- Sets the
Destination
object for this message.
JMS providers set this field when a message is sent. This method
can be used to change the value for a message that has been received.
- Parameters:
destination
- the destination for this message
- Throws:
JMSException
- if the JMS provider fails to set the destination
due to some internal error.- See Also:
getJMSDestination()
getJMSDeliveryMode
int getJMSDeliveryMode()
throws JMSException
- Gets the
DeliveryMode
value specified for this message.
- Returns:
- the delivery mode for this message
- Throws:
JMSException
- if the JMS provider fails to get the
delivery mode due to some internal error.- See Also:
setJMSDeliveryMode(int)
,
DeliveryMode
setJMSDeliveryMode
void setJMSDeliveryMode(int deliveryMode)
throws JMSException
- Sets the
DeliveryMode
value for this message.
JMS providers set this field when a message is sent. This method
can be used to change the value for a message that has been received.
- Parameters:
deliveryMode
- the delivery mode for this message
- Throws:
JMSException
- if the JMS provider fails to set the
delivery mode due to some internal error.- See Also:
getJMSDeliveryMode()
,
DeliveryMode
getJMSRedelivered
boolean getJMSRedelivered()
throws JMSException
- Gets an indication of whether this message is being redelivered.
If a client receives a message with the JMSRedelivered
field set,
it is likely, but not guaranteed, that this message was delivered
earlier but that its receipt was not acknowledged
at that time.
- Returns:
- true if this message is being redelivered
- Throws:
JMSException
- if the JMS provider fails to get the redelivered
state due to some internal error.- See Also:
setJMSRedelivered(boolean)
setJMSRedelivered
void setJMSRedelivered(boolean redelivered)
throws JMSException
- Specifies whether this message is being redelivered.
This field is set at the time the message is delivered. This
method can be used to change the value for a message that has
been received.
- Parameters:
redelivered
- an indication of whether this message is being
redelivered
- Throws:
JMSException
- if the JMS provider fails to set the redelivered
state due to some internal error.- See Also:
getJMSRedelivered()
getJMSType
java.lang.String getJMSType()
throws JMSException
- Gets the message type identifier supplied by the client when the
message was sent.
- Returns:
- the message type
- Throws:
JMSException
- if the JMS provider fails to get the message
type due to some internal error.- See Also:
setJMSType(String)
setJMSType
void setJMSType(java.lang.String type)
throws JMSException
- Sets the message type.
Some JMS providers use a message repository that contains the
definitions of messages sent by applications. The JMSType
header field may reference a message's definition in the provider's
repository.
The JMS API does not define a standard message definition repository,
nor does it define a naming policy for the definitions it contains.
Some messaging systems require that a message type definition for
each application message be created and that each message specify its
type. In order to work with such JMS providers, JMS clients should
assign a value to JMSType
, whether the application makes
use of it or not. This ensures that the field is properly set for those
providers that require it.
To ensure portability, JMS clients should use symbolic values for
JMSType
that can be configured at installation time to the
values defined in the current provider's message repository. If string
literals are used, they may not be valid type names for some JMS
providers.
- Parameters:
type
- the message type
- Throws:
JMSException
- if the JMS provider fails to set the message
type due to some internal error.- See Also:
getJMSType()
getJMSExpiration
long getJMSExpiration()
throws JMSException
- Gets the message's expiration value.
When a message is sent, the JMSExpiration
header field
is left unassigned. After completion of the send
or
publish
method, it holds the expiration time of the
message. This is the sum of the time-to-live value specified by the
client and the GMT at the time of the send
or
publish
.
If the time-to-live is specified as zero, JMSExpiration
is set to zero to indicate that the message does not expire.
When a message's expiration time is reached, a provider should
discard it. The JMS API does not define any form of notification of
message expiration.
Clients should not receive messages that have expired; however,
the JMS API does not guarantee that this will not happen.
- Returns:
- the time the message expires, which is the sum of the
time-to-live value specified by the client and the GMT at the
time of the send
- Throws:
JMSException
- if the JMS provider fails to get the message
expiration due to some internal error.- See Also:
setJMSExpiration(long)
setJMSExpiration
void setJMSExpiration(long expiration)
throws JMSException
- Sets the message's expiration value.
JMS providers set this field when a message is sent. This method
can be used to change the value for a message that has been received.
- Parameters:
expiration
- the message's expiration time
- Throws:
JMSException
- if the JMS provider fails to set the message
expiration due to some internal error.- See Also:
getJMSExpiration()
getJMSPriority
int getJMSPriority()
throws JMSException
- Gets the message priority level.
The JMS API defines ten levels of priority value, with 0 as the
lowest
priority and 9 as the highest. In addition, clients should consider
priorities 0-4 as gradations of normal priority and priorities 5-9
as gradations of expedited priority.
The JMS API does not require that a provider strictly implement
priority
ordering of messages; however, it should do its best to deliver
expedited messages ahead of normal messages.
- Returns:
- the default message priority
- Throws:
JMSException
- if the JMS provider fails to get the message
priority due to some internal error.- See Also:
setJMSPriority(int)
setJMSPriority
void setJMSPriority(int priority)
throws JMSException
- Sets the priority level for this message.
JMS providers set this field when a message is sent. This method
can be used to change the value for a message that has been received.
- Parameters:
priority
- the priority of this message
- Throws:
JMSException
- if the JMS provider fails to set the message
priority due to some internal error.- See Also:
getJMSPriority()
clearProperties
void clearProperties()
throws JMSException
- Clears a message's properties.
The message's header fields and body are not cleared.
- Throws:
JMSException
- if the JMS provider fails to clear the message
properties due to some internal error.
propertyExists
boolean propertyExists(java.lang.String name)
throws JMSException
- Indicates whether a property value exists.
- Parameters:
name
- the name of the property to test
- Returns:
- true if the property exists
- Throws:
JMSException
- if the JMS provider fails to determine if the
property exists due to some internal error.
getBooleanProperty
boolean getBooleanProperty(java.lang.String name)
throws JMSException
- Returns the value of the
boolean
property with the
specified name.
- Parameters:
name
- the name of the boolean
property
- Returns:
- the
boolean
property value for the specified name
- Throws:
JMSException
- if the JMS provider fails to get the property
value due to some internal error.
MessageFormatException
- if this type conversion is invalid.
getByteProperty
byte getByteProperty(java.lang.String name)
throws JMSException
- Returns the value of the
byte
property with the specified
name.
- Parameters:
name
- the name of the byte
property
- Returns:
- the
byte
property value for the specified name
- Throws:
JMSException
- if the JMS provider fails to get the property
value due to some internal error.
MessageFormatException
- if this type conversion is invalid.
getShortProperty
short getShortProperty(java.lang.String name)
throws JMSException
- Returns the value of the
short
property with the specified
name.
- Parameters:
name
- the name of the short
property
- Returns:
- the
short
property value for the specified name
- Throws:
JMSException
- if the JMS provider fails to get the property
value due to some internal error.
MessageFormatException
- if this type conversion is invalid.
getIntProperty
int getIntProperty(java.lang.String name)
throws JMSException
- Returns the value of the
int
property with the specified
name.
- Parameters:
name
- the name of the int
property
- Returns:
- the
int
property value for the specified name
- Throws:
JMSException
- if the JMS provider fails to get the property
value due to some internal error.
MessageFormatException
- if this type conversion is invalid.
getLongProperty
long getLongProperty(java.lang.String name)
throws JMSException
- Returns the value of the
long
property with the specified
name.
- Parameters:
name
- the name of the long
property
- Returns:
- the
long
property value for the specified name
- Throws:
JMSException
- if the JMS provider fails to get the property
value due to some internal error.
MessageFormatException
- if this type conversion is invalid.
getFloatProperty
float getFloatProperty(java.lang.String name)
throws JMSException
- Returns the value of the
float
property with the specified
name.
- Parameters:
name
- the name of the float
property
- Returns:
- the
float
property value for the specified name
- Throws:
JMSException
- if the JMS provider fails to get the property
value due to some internal error.
MessageFormatException
- if this type conversion is invalid.
getDoubleProperty
double getDoubleProperty(java.lang.String name)
throws JMSException
- Returns the value of the
double
property with the specified
name.
- Parameters:
name
- the name of the double
property
- Returns:
- the
double
property value for the specified name
- Throws:
JMSException
- if the JMS provider fails to get the property
value due to some internal error.
MessageFormatException
- if this type conversion is invalid.
getStringProperty
java.lang.String getStringProperty(java.lang.String name)
throws JMSException
- Returns the value of the
String
property with the specified
name.
- Parameters:
name
- the name of the String
property
- Returns:
- the
String
property value for the specified name;
if there is no property by this name, a null value is returned
- Throws:
JMSException
- if the JMS provider fails to get the property
value due to some internal error.
MessageFormatException
- if this type conversion is invalid.
getObjectProperty
java.lang.Object getObjectProperty(java.lang.String name)
throws JMSException
- Returns the value of the Java object property with the specified name.
This method can be used to return, in objectified format,
an object that has been stored as a property in the message with the
equivalent setObjectProperty
method call, or its equivalent
primitive settypeProperty
method.
- Parameters:
name
- the name of the Java object property
- Returns:
- the Java object property value with the specified name, in
objectified format (for example, if the property was set as an
int
, an Integer
is
returned); if there is no property by this name, a null value
is returned
- Throws:
JMSException
- if the JMS provider fails to get the property
value due to some internal error.
getPropertyNames
java.util.Enumeration getPropertyNames()
throws JMSException
- Returns an
Enumeration
of all the property names.
Note that JMS standard header fields are not considered
properties and are not returned in this enumeration.
- Returns:
- an enumeration of all the names of property values
- Throws:
JMSException
- if the JMS provider fails to get the property
names due to some internal error.
setBooleanProperty
void setBooleanProperty(java.lang.String name,
boolean value)
throws JMSException
- Sets a
boolean
property value with the specified name into
the message.
- Parameters:
name
- the name of the boolean
propertyvalue
- the boolean
property value to set
- Throws:
JMSException
- if the JMS provider fails to set the property
due to some internal error.
java.lang.IllegalArgumentException
- if the name is null or if the name is
an empty string.
MessageNotWriteableException
- if properties are read-only
setByteProperty
void setByteProperty(java.lang.String name,
byte value)
throws JMSException
- Sets a
byte
property value with the specified name into
the message.
- Parameters:
name
- the name of the byte
propertyvalue
- the byte
property value to set
- Throws:
JMSException
- if the JMS provider fails to set the property
due to some internal error.
java.lang.IllegalArgumentException
- if the name is null or if the name is
an empty string.
MessageNotWriteableException
- if properties are read-only
setShortProperty
void setShortProperty(java.lang.String name,
short value)
throws JMSException
- Sets a
short
property value with the specified name into
the message.
- Parameters:
name
- the name of the short
propertyvalue
- the short
property value to set
- Throws:
JMSException
- if the JMS provider fails to set the property
due to some internal error.
java.lang.IllegalArgumentException
- if the name is null or if the name is
an empty string.
MessageNotWriteableException
- if properties are read-only
setIntProperty
void setIntProperty(java.lang.String name,
int value)
throws JMSException
- Sets an
int
property value with the specified name into
the message.
- Parameters:
name
- the name of the int
propertyvalue
- the int
property value to set
- Throws:
JMSException
- if the JMS provider fails to set the property
due to some internal error.
java.lang.IllegalArgumentException
- if the name is null or if the name is
an empty string.
MessageNotWriteableException
- if properties are read-only
setLongProperty
void setLongProperty(java.lang.String name,
long value)
throws JMSException
- Sets a
long
property value with the specified name into
the message.
- Parameters:
name
- the name of the long
propertyvalue
- the long
property value to set
- Throws:
JMSException
- if the JMS provider fails to set the property
due to some internal error.
java.lang.IllegalArgumentException
- if the name is null or if the name is
an empty string.
MessageNotWriteableException
- if properties are read-only
setFloatProperty
void setFloatProperty(java.lang.String name,
float value)
throws JMSException
- Sets a
float
property value with the specified name into
the message.
- Parameters:
name
- the name of the float
propertyvalue
- the float
property value to set
- Throws:
JMSException
- if the JMS provider fails to set the property
due to some internal error.
java.lang.IllegalArgumentException
- if the name is null or if the name is
an empty string.
MessageNotWriteableException
- if properties are read-only
setDoubleProperty
void setDoubleProperty(java.lang.String name,
double value)
throws JMSException
- Sets a
double
property value with the specified name into
the message.
- Parameters:
name
- the name of the double
propertyvalue
- the double
property value to set
- Throws:
JMSException
- if the JMS provider fails to set the property
due to some internal error.
java.lang.IllegalArgumentException
- if the name is null or if the name is
an empty string.
MessageNotWriteableException
- if properties are read-only
setStringProperty
void setStringProperty(java.lang.String name,
java.lang.String value)
throws JMSException
- Sets a
String
property value with the specified name into
the message.
- Parameters:
name
- the name of the String
propertyvalue
- the String
property value to set
- Throws:
JMSException
- if the JMS provider fails to set the property
due to some internal error.
java.lang.IllegalArgumentException
- if the name is null or if the name is
an empty string.
MessageNotWriteableException
- if properties are read-only
setObjectProperty
void setObjectProperty(java.lang.String name,
java.lang.Object value)
throws JMSException
- Sets a Java object property value with the specified name into the
message.
Note that this method works only for the objectified primitive
object types (Integer
, Double
,
Long
...) and String
objects.
- Parameters:
name
- the name of the Java object propertyvalue
- the Java object property value to set
- Throws:
JMSException
- if the JMS provider fails to set the property
due to some internal error.
java.lang.IllegalArgumentException
- if the name is null or if the name is
an empty string.
MessageFormatException
- if the object is invalid
MessageNotWriteableException
- if properties are read-only
acknowledge
void acknowledge()
throws JMSException
- Acknowledges all consumed messages of the session of this consumed
message.
All consumed JMS messages support the acknowledge
method for use when a client has specified that its JMS session's
consumed messages are to be explicitly acknowledged. By invoking
acknowledge
on a consumed message, a client acknowledges
all messages consumed by the session that the message was delivered to.
Calls to acknowledge
are ignored for both transacted
sessions and sessions specified to use implicit acknowledgement modes.
A client may individually acknowledge each message as it is consumed,
or it may choose to acknowledge messages as an application-defined group
(which is done by calling acknowledge on the last received message of the group,
thereby acknowledging all messages consumed by the session.)
Messages that have been received but not acknowledged may be
redelivered.
- Throws:
JMSException
- if the JMS provider fails to acknowledge the
messages due to some internal error.
IllegalStateException
- if this method is called on a closed
session.- See Also:
Session.CLIENT_ACKNOWLEDGE
clearBody
void clearBody()
throws JMSException
- Clears out the message body. Clearing a message's body does not clear
its header values or property entries.
If this message body was read-only, calling this method leaves
the message body in the same state as an empty body in a newly
created message.
- Throws:
JMSException
- if the JMS provider fails to clear the message
body due to some internal error.