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/*
* Copyright (c) 1997, 2017 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package javax.jms;
import java.util.Enumeration;
/**
* The {@code Message} interface is the root interface of all Jakarta Messaging messages. It defines the message header and the
* {@code acknowledge} method used for all messages.
*
*
* Most message-oriented middleware (MOM) products treat messages as lightweight entities that consist of a header and a
* body. The header contains fields used for message routing and identification; the body 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 Jakarta Messaging API to support all of these message models.
*
*
* With this in mind, the Jakarta Messaging message model has the following goals:
*
* - Provide a single, unified message API
*
- Provide an API suitable for creating messages that match the format used by provider-native messaging
* applications
*
- Support the development of heterogeneous applications that span operating systems, machine architectures, and
* computer languages
*
- Support messages containing objects in the Java programming language ("Java objects")
*
- Support messages containing Extensible Markup Language (XML) pages
*
*
*
* Jakarta Messaging messages are composed of the following parts:
*
* - Header - All messages support the same set of header fields. Header fields contain values used by both clients
* and providers to identify and route messages.
*
- Properties - Each message contains a built-in facility for supporting application-defined property values.
* Properties provide an efficient mechanism for supporting application-defined message filtering.
*
- Body - The Jakarta Messaging API defines several types of message body, which cover the majority of messaging styles currently
* in use.
*
*
* Message Bodies
*
*
* The Jakarta Messaging API defines five types of message body:
*
* - Stream - A {@code StreamMessage} object's message body contains a stream of primitive values in the Java
* programming language ("Java primitives"). It is filled and read sequentially.
*
- Map - A {@code MapMessage} object's message body contains a set of name-value pairs, where names are
* {@code String} objects, and values are Java primitives. The entries can be accessed sequentially or randomly by name.
* The order of the entries is undefined.
*
- Text - A {@code TextMessage} object's message body contains a {@code java.lang.String} object. This message type
* can be used to transport plain-text messages, and XML messages.
*
- Object - An {@code ObjectMessage} object's message body contains a {@code Serializable} Java object.
*
- Bytes - A {@code 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 Jakarta Messaging API allows the use of message properties with byte
* messages, they are typically not used, since the inclusion of properties may affect the format.
*
*
* Message Headers
*
*
* The {@code JMSCorrelationID} header field is used for linking one message with another. It typically links a reply
* message with its requesting message.
*
*
* {@code JMSCorrelationID} can hold a provider-specific message ID, an application-specific {@code String} object, or a
* provider-native {@code byte[]} value.
*
*
Message Properties
*
*
* A {@code 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 Jakarta Messaging 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
* {@code IllegalArgumentException} must be thrown.
*
*
* Property values can be {@code boolean}, {@code byte}, {@code short}, {@code int}, {@code long}, {@code float},
* {@code double}, and {@code 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 {@code MessageNotWriteableException} is thrown. If
* {@code 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 Jakarta Messaging does not define a policy for
* what should or should not be made a property, application developers should note that Jakarta Messaging 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 {@code JMSException}. The {@code String}-to-primitive conversions may throw a runtime exception if the
* primitive's {@code valueOf} method does not accept the {@code 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, Jakarta Messaging provides the {@code setObjectProperty} and
* {@code 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 {@code setObjectProperty} method accepts values of class {@code Boolean}, {@code Byte}, {@code Short},
* {@code Integer}, {@code Long}, {@code Float}, {@code Double}, and {@code String}. An attempt to use any other class
* must throw a {@code JMSException}.
*
*
* The {@code getObjectProperty} method only returns values of class {@code Boolean}, {@code Byte}, {@code Short},
* {@code Integer}, {@code Long}, {@code Float}, {@code Double}, and {@code String}.
*
*
* The order of property values is not defined. To iterate through a message's property values, use
* {@code 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 {@code 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 {@code getStringProperty}
* and {@code 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 {@code valueOf(String)} conversion method with a null value.
*
*
* The Jakarta Messaging API reserves the {@code JMSX} property name prefix for Jakarta Messaging defined properties. The full set of these
* properties is defined in the Jakarta Messaging specification. The specification also defines whether support for
* each property is mandatory or optional. New Jakarta Messaging defined properties may be added in later versions of the Jakarta Messaging API. The
* {@code 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. The effect of setting a message selector
* on a property which is set by the provider on receive is undefined.
*
*
* 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.
*
*
* {@code JMSXGroupID} and {@code 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 Jakarta Messaging 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 Jakarta Messaging provider uses to
* make its special per-message services available to a Jakarta Messaging client.
*
*
* The purpose of provider-specific properties is to provide special features needed to integrate Jakarta Messaging clients with
* provider-native clients in a single Jakarta Messaging application. They should not be used for messaging between Jakarta Messaging clients.
*
*
Provider Implementations of Jakarta Messaging Message Interfaces
*
*
* The Jakarta Messaging API provides a set of message interfaces that define the Jakarta Messaging message model. It does not provide
* implementations of these interfaces.
*
*
* Each Jakarta Messaging provider supplies a set of message factories with its {@code 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 {@code 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.
*
*
Message Selectors
*
*
* A Jakarta Messaging 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 {@code MessageConsumer} being used (see
* {@link javax.jms.QueueReceiver QueueReceiver} and {@link javax.jms.TopicSubscriber 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 {@code 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:
*
*
* - Literals:
*
* - A string literal is enclosed in single quotes, with a single quote represented by doubled single quote; for
* example, {@code 'literal'} and {@code 'literal''s'}. Like string literals in the Java programming language, these use
* the Unicode character encoding.
*
- An exact numeric literal is a numeric value without a decimal point, such as {@code 57}, {@code -957}, and
* {@code +62}; numbers in the range of {@code long} are supported. Exact numeric literals use the integer literal
* syntax of the Java programming language.
*
- An approximate numeric literal is a numeric value in scientific notation, such as {@code 7E3} and
* {@code -57.9E2}, or a numeric value with a decimal, such as {@code 7.}, {@code -95.7}, and {@code +6.2}; numbers in
* the range of {@code double} are supported. Approximate literals use the floating-point literal syntax of the Java
* programming language.
*
- The boolean literals {@code TRUE} and {@code FALSE}.
*
*
* - Identifiers:
*
* - An identifier is an unlimited-length sequence of letters and digits, the first of which must be a letter. A
* letter is any character for which the method {@code Character.isJavaLetter} returns true. This includes {@code '_'}
* and {@code '$'}. A letter or digit is any character for which the method {@code Character.isJavaLetterOrDigit}
* returns true.
*
- Identifiers cannot be the names {@code NULL}, {@code TRUE}, and {@code FALSE}.
*
- Identifiers cannot be {@code NOT}, {@code AND}, {@code OR}, {@code BETWEEN}, {@code LIKE}, {@code IN},
* {@code IS}, or {@code ESCAPE}.
*
- Identifiers are either header field references or property references. The type of a property value in a message
* selector corresponds to the type used to set the property. If a property that does not exist in a message is
* referenced, its value is {@code NULL}.
*
- The conversions that apply to the get methods for properties do not apply when a property is used in a message
* selector expression. For example, suppose you set a property as a string value, as in the following:
*
*
* 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"
*
*
* - Identifiers are case-sensitive.
*
- Message header field references are restricted to {@code JMSDeliveryMode}, {@code JMSPriority},
* {@code JMSMessageID}, {@code JMSTimestamp}, {@code JMSCorrelationID}, and {@code JMSType}. {@code JMSMessageID},
* {@code JMSCorrelationID}, and {@code JMSType} values may be null and if so are treated as a {@code NULL} value.
*
- Any name beginning with {@code 'JMSX'} is a Jakarta Messaging defined property name.
*
- Any name beginning with {@code 'JMS_'} is a provider-specific property name.
*
- Any name that does not begin with {@code 'JMS'} is an application-specific property name.
*
*
* - White space is the same as that defined for the Java programming language: space, horizontal tab, form feed, and
* line terminator.
*
*
- Expressions:
*
* - A selector is a conditional expression; a selector that evaluates to {@code true} matches; a selector that
* evaluates to {@code false} or unknown does not match.
*
- Arithmetic expressions are composed of themselves, arithmetic operations, identifiers (whose value is treated as
* a numeric literal), and numeric literals.
*
- Conditional expressions are composed of themselves, comparison operations, and logical operations.
*
*
* - Standard bracketing {@code ()} for ordering expression evaluation is supported.
*
- Logical operators in precedence order: {@code NOT}, {@code AND}, {@code OR}
*
- Comparison operators: {@code =}, {@code >}, {@code >=}, {@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 {@code NULL}, the value of the expression is unknown.
*
- String and boolean comparison is restricted to {@code =} and {@code <>}. Two strings are equal if and only if
* they contain the same sequence of characters.
*
*
* - Arithmetic operators in precedence order:
*
* - {@code +}, {@code -} (unary)
*
- {@code *}, {@code /} (multiplication and division)
*
- {@code +}, {@code -} (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"
* "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"
*
*
*
*
* Jakarta Messaging 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 {@code JMSException}. Jakarta Messaging 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 {@code NULL}. The evaluation of selector expressions containing {@code NULL}
* values is defined by SQL92 {@code NULL} semantics. A brief description of these semantics is provided here.
*
*
* SQL treats a {@code NULL} value as unknown. Comparison or arithmetic with an unknown value always yields an unknown
* value.
*
*
* The {@code IS NULL} and {@code IS NOT NULL} operators convert an unknown value into the respective {@code TRUE} and
* {@code FALSE} values.
*
*
* The boolean operators use three-valued logic as defined by the following tables:
*
*
* The definition of the {@code AND} operator
*
*
* | AND | T | F | U
* +------+-------+-------+-------
* | T | T | F | U
* | F | F | F | F
* | U | U | F | U
* +------+-------+-------+-------
*
*
*
* The definition of the {@code OR} operator
*
*
* | OR | T | F | U
* +------+-------+-------+--------
* | T | T | T | T
* | F | T | F | U
* | U | T | U | U
* +------+-------+-------+-------
*
*
*
* The definition of the {@code NOT} operator
*
*
* | NOT
* +------+------
* | T | F
* | F | T
* | U | U
* +------+-------
*
*
* Special Notes
*
*
* When used in a message selector, the {@code JMSDeliveryMode} header field is treated as having the values
* {@code 'PERSISTENT'} and {@code 'NON_PERSISTENT'}.
*
*
* Date and time values should use the standard {@code 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 {@code java.util.Calendar}.
*
*
* Although SQL supports fixed decimal comparison and arithmetic, Jakarta Messaging 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.
*
* @version Jakarta Messaging 2.0
* @since JMS 1.0
*
* @see javax.jms.MessageConsumer#receive()
* @see javax.jms.MessageConsumer#receive(long)
* @see javax.jms.MessageConsumer#receiveNoWait()
* @see javax.jms.MessageListener#onMessage(Message)
* @see javax.jms.BytesMessage
* @see javax.jms.MapMessage
* @see javax.jms.ObjectMessage
* @see javax.jms.StreamMessage
* @see javax.jms.TextMessage
*/
public interface Message {
/**
* The message producer's default delivery mode is {@code PERSISTENT}.
*
* @see DeliveryMode#PERSISTENT
*/
int DEFAULT_DELIVERY_MODE = DeliveryMode.PERSISTENT;
/**
* The message producer's default priority is 4.
*/
int DEFAULT_PRIORITY = 4;
/**
* The message producer's default time to live is unlimited; the message never expires.
*/
long DEFAULT_TIME_TO_LIVE = 0;
/**
* The message producer's default delivery delay is zero.
*
* @since JMS 2.0
*/
long DEFAULT_DELIVERY_DELAY = 0;
/**
* Gets the message ID.
*
*
* The {@code JMSMessageID} header field contains a value that uniquely identifies each message sent by a provider.
*
*
* When a message is sent, {@code JMSMessageID} can be ignored. When the {@code send} or {@code publish} method returns,
* it contains a provider-assigned value.
*
*
* A {@code JMSMessageID} is a {@code 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 {@code JMSMessageID} values must start with the prefix {@code '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 Jakarta Messaging 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
* {@code MessageProducer.setDisableMessageID} method, a Jakarta Messaging client enables this potential optimization for all messages
* sent by that message producer. If the Jakarta Messaging 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.
*
* @return the message ID
*
* @exception JMSException if the Jakarta Messaging provider fails to get the message ID due to some internal error.
* @see javax.jms.Message#setJMSMessageID(String)
* @see javax.jms.MessageProducer#setDisableMessageID(boolean)
*/
String getJMSMessageID() throws JMSException;
/**
* Sets the message ID.
*
*
* This method is for use by Jakarta Messaging providers only to set this field when a message is sent. This message cannot be used by
* clients to configure the message ID. This method is public to allow a Jakarta Messaging provider to set this field when sending a
* message whose implementation is not its own.
*
* @param id the ID of the message
*
* @exception JMSException if the Jakarta Messaging provider fails to set the message ID due to some internal error.
*
* @see javax.jms.Message#getJMSMessageID()
*/
void setJMSMessageID(String id) throws JMSException;
/**
* Gets the message timestamp.
*
*
* The {@code 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, {@code JMSTimestamp} is ignored. When the {@code send} or {@code 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 Jakarta Messaging 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
* {@code MessageProducer.setDisableMessageTimestamp} method, a Jakarta Messaging client enables this potential optimization for all
* messages sent by that message producer. If the Jakarta Messaging 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.
*
* @return the message timestamp
*
* @exception JMSException if the Jakarta Messaging provider fails to get the timestamp due to some internal error.
*
* @see javax.jms.Message#setJMSTimestamp(long)
* @see javax.jms.MessageProducer#setDisableMessageTimestamp(boolean)
*/
long getJMSTimestamp() throws JMSException;
/**
* Sets the message timestamp.
*
*
* This method is for use by Jakarta Messaging providers only to set this field when a message is sent. This message cannot be used by
* clients to configure the message timestamp. This method is public to allow a Jakarta Messaging provider to set this field when
* sending a message whose implementation is not its own.
*
* @param timestamp the timestamp for this message
*
* @exception JMSException if the Jakarta Messaging provider fails to set the timestamp due to some internal error.
*
* @see javax.jms.Message#getJMSTimestamp()
*/
void setJMSTimestamp(long timestamp) throws JMSException;
/**
* Gets the correlation ID as an array of bytes for the message.
*
*
* The use of a {@code byte[]} value for {@code JMSCorrelationID} is non-portable.
*
* @return the correlation ID of a message as an array of bytes
*
* @exception JMSException if the Jakarta Messaging provider fails to get the correlation ID due to some internal error.
*
* @see javax.jms.Message#setJMSCorrelationID(String)
* @see javax.jms.Message#getJMSCorrelationID()
* @see javax.jms.Message#setJMSCorrelationIDAsBytes(byte[])
*/
byte[] getJMSCorrelationIDAsBytes() 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 Jakarta Messaging client may need to assign specific
* {@code JMSCorrelationID} values to match those expected by native messaging clients. Jakarta Messaging providers without native
* correlation ID values are not required to support this method and its corresponding get method; their implementation
* may throw a {@code java.lang.UnsupportedOperationException}.
*
*
* The use of a {@code byte[]} value for {@code JMSCorrelationID} is non-portable.
*
* @param correlationID the correlation ID value as an array of bytes
*
* @exception JMSException if the Jakarta Messaging provider fails to set the correlation ID due to some internal error.
*
* @see javax.jms.Message#setJMSCorrelationID(String)
* @see javax.jms.Message#getJMSCorrelationID()
* @see javax.jms.Message#getJMSCorrelationIDAsBytes()
*/
void setJMSCorrelationIDAsBytes(byte[] correlationID) throws JMSException;
/**
* Sets the correlation ID for the message.
*
*
* A client can use the {@code JMSCorrelationID} header field to link one message with another. A typical use is to link
* a response message with its request message.
*
*
* {@code JMSCorrelationID} can hold one of the following:
*
* - A provider-specific message ID
*
- An application-specific {@code String}
*
- A provider-native {@code byte[]} value
*
*
*
* Since each message sent by a Jakarta Messaging provider is assigned a message ID value, it is convenient to link messages via
* message ID. All message ID values must start with the {@code '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 {@code JMSCorrelationID} to hold a value referencing some external
* information. Application-specified values must not start with the {@code 'ID:'} prefix; this is reserved for
* provider-generated message ID values.
*
*
* If a provider supports the native concept of correlation ID, a Jakarta Messaging client may need to assign specific
* {@code JMSCorrelationID} values to match those expected by clients that do not use the Jakarta Messaging API. A {@code byte[]}
* value is used for this purpose. Jakarta Messaging providers without native correlation ID values are not required to support
* {@code byte[]} values. The use of a {@code byte[]} value for {@code JMSCorrelationID} is non-portable.
*
* @param correlationID the message ID of a message being referred to
*
* @exception JMSException if the Jakarta Messaging provider fails to set the correlation ID due to some internal error.
*
* @see javax.jms.Message#getJMSCorrelationID()
* @see javax.jms.Message#getJMSCorrelationIDAsBytes()
* @see javax.jms.Message#setJMSCorrelationIDAsBytes(byte[])
*/
void setJMSCorrelationID(String correlationID) 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 {@code String} values.
*
* @return the correlation ID of a message as a {@code String}
*
* @exception JMSException if the Jakarta Messaging provider fails to get the correlation ID due to some internal error.
*
* @see javax.jms.Message#setJMSCorrelationID(String)
* @see javax.jms.Message#getJMSCorrelationIDAsBytes()
* @see javax.jms.Message#setJMSCorrelationIDAsBytes(byte[])
*/
String getJMSCorrelationID() throws JMSException;
/**
* Gets the {@code Destination} object to which a reply to this message should be sent.
*
* @return {@code Destination} to which to send a response to this message
*
* @exception JMSException if the Jakarta Messaging provider fails to get the {@code JMSReplyTo} destination due to some internal
* error.
*
* @see javax.jms.Message#setJMSReplyTo(Destination)
*/
Destination getJMSReplyTo() throws JMSException;
/**
* Sets the {@code Destination} object to which a reply to this message should be sent.
*
*
* The {@code 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 {@code Queue} object or a {@code Topic} object.
*
*
* Messages sent with a null {@code 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 {@code 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 {@code JMSCorrelationID} header field for this purpose.
*
* @param replyTo {@code Destination} to which to send a response to this message
*
* @exception JMSException if the Jakarta Messaging provider fails to set the {@code JMSReplyTo} destination due to some internal
* error.
*
* @see javax.jms.Message#getJMSReplyTo()
*/
void setJMSReplyTo(Destination replyTo) throws JMSException;
/**
* Gets the {@code Destination} object for this message.
*
*
* The {@code 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 {@code send} or {@code publish} method, the
* field holds the destination specified by the method.
*
*
* When a message is received, its {@code JMSDestination} value must be equivalent to the value assigned when it was
* sent.
*
* @return the destination of this message
*
* @exception JMSException if the Jakarta Messaging provider fails to get the destination due to some internal error.
*
* @see javax.jms.Message#setJMSDestination(Destination)
*/
Destination getJMSDestination() throws JMSException;
/**
* Sets the {@code Destination} object for this message.
*
*
* This method is for use by Jakarta Messaging providers only to set this field when a message is sent. This message cannot be used by
* clients to configure the destination of the message. This method is public to allow a Jakarta Messaging provider to set this field
* when sending a message whose implementation is not its own.
*
* @param destination the destination for this message
*
* @exception JMSException if the Jakarta Messaging provider fails to set the destination due to some internal error.
*
* @see javax.jms.Message#getJMSDestination()
*/
void setJMSDestination(Destination destination) throws JMSException;
/**
* Gets the {@code DeliveryMode} value specified for this message.
*
* @return the delivery mode for this message
*
* @exception JMSException if the Jakarta Messaging provider fails to get the delivery mode due to some internal error.
*
* @see javax.jms.Message#setJMSDeliveryMode(int)
* @see javax.jms.DeliveryMode
*/
int getJMSDeliveryMode() throws JMSException;
/**
* Sets the {@code DeliveryMode} value for this message.
*
*
* This method is for use by Jakarta Messaging providers only to set this field when a message is sent. This message cannot be used by
* clients to configure the delivery mode of the message. This method is public to allow a Jakarta Messaging provider to set this
* field when sending a message whose implementation is not its own.
*
* @param deliveryMode the delivery mode for this message
*
* @exception JMSException if the Jakarta Messaging provider fails to set the delivery mode due to some internal error.
*
* @see javax.jms.Message#getJMSDeliveryMode()
* @see javax.jms.DeliveryMode
*/
void setJMSDeliveryMode(int deliveryMode) throws JMSException;
/**
* Gets an indication of whether this message is being redelivered.
*
*
* If a client receives a message with the {@code 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.
*
* @return true if this message is being redelivered
*
* @exception JMSException if the Jakarta Messaging provider fails to get the redelivered state due to some internal error.
*
* @see javax.jms.Message#setJMSRedelivered(boolean)
*/
boolean getJMSRedelivered() throws JMSException;
/**
* Specifies whether this message is being redelivered.
*
*
* This method is for use by Jakarta Messaging providers only to set this field when a message is delivered. This message cannot be
* used by clients to configure the redelivered status of the message. This method is public to allow a Jakarta Messaging provider to
* set this field when sending a message whose implementation is not its own.
*
* @param redelivered an indication of whether this message is being redelivered
*
* @exception JMSException if the Jakarta Messaging provider fails to set the redelivered state due to some internal error.
*
* @see javax.jms.Message#getJMSRedelivered()
*/
void setJMSRedelivered(boolean redelivered) throws JMSException;
/**
* Gets the message type identifier supplied by the client when the message was sent.
*
* @return the message type
*
* @exception JMSException if the Jakarta Messaging provider fails to get the message type due to some internal error.
*
* @see javax.jms.Message#setJMSType(String)
*/
String getJMSType() throws JMSException;
/**
* Sets the message type.
*
*
* Some Jakarta Messaging providers use a message repository that contains the definitions of messages sent by applications. The
* {@code JMSType} header field may reference a message's definition in the provider's repository.
*
*
* The Jakarta Messaging 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 Jakarta Messaging providers, Jakarta Messaging clients should assign a value to
* {@code 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, Jakarta Messaging clients should use symbolic values for {@code 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 Jakarta Messaging providers.
*
* @param type the message type
*
* @exception JMSException if the Jakarta Messaging provider fails to set the message type due to some internal error.
*
* @see javax.jms.Message#getJMSType()
*/
void setJMSType(String type) throws JMSException;
/**
* Gets the message's expiration time.
*
*
* When a message is sent, the {@code JMSExpiration} header field is left unassigned. After completion of the
* {@code send} or {@code publish} method, it holds the expiration time of the message. This is the the difference,
* measured in milliseconds, between the expiration time and midnight, January 1, 1970 UTC.
*
*
* If the time-to-live is specified as zero, {@code 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 Jakarta Messaging API does not define any form of
* notification of message expiration.
*
*
* Clients should not receive messages that have expired; however, the Jakarta Messaging API does not guarantee that this will not
* happen.
*
* @return the message's expiration time value
*
* @exception JMSException if the Jakarta Messaging provider fails to get the message expiration due to some internal error.
*
* @see javax.jms.Message#setJMSExpiration(long)
*/
long getJMSExpiration() throws JMSException;
/**
* Sets the message's expiration value.
*
*
* This method is for use by Jakarta Messaging providers only to set this field when a message is sent. This message cannot be used by
* clients to configure the expiration time of the message. This method is public to allow a Jakarta Messaging provider to set this
* field when sending a message whose implementation is not its own.
*
* @param expiration the message's expiration time
*
* @exception JMSException if the Jakarta Messaging provider fails to set the message expiration due to some internal error.
*
* @see javax.jms.Message#getJMSExpiration()
*/
void setJMSExpiration(long expiration) throws JMSException;
/**
* Gets the message's delivery time value.
*
*
* When a message is sent, the {@code JMSDeliveryTime} header field is left unassigned. After completion of the
* {@code send} or {@code publish} method, it holds the delivery time of the message. This is the the difference,
* measured in milliseconds, between the delivery time and midnight, January 1, 1970 UTC.
*
*
* A message's delivery time is the earliest time when a Jakarta Messaging provider may deliver the message to a consumer. The
* provider must not deliver messages before the delivery time has been reached.
*
* @return the message's delivery time value
*
* @exception JMSException if the Jakarta Messaging provider fails to get the delivery time due to some internal error.
*
* @see javax.jms.Message#setJMSDeliveryTime(long)
*
* @since JMS 2.0
*/
long getJMSDeliveryTime() throws JMSException;
/**
* Sets the message's delivery time value.
*
*
* This method is for use by Jakarta Messaging providers only to set this field when a message is sent. This message cannot be used by
* clients to configure the delivery time of the message. This method is public to allow a Jakarta Messaging provider to set this
* field when sending a message whose implementation is not its own.
*
* @param deliveryTime the message's delivery time value
*
* @exception JMSException if the Jakarta Messaging provider fails to set the delivery time due to some internal error.
*
* @see javax.jms.Message#getJMSDeliveryTime()
*
* @since JMS 2.0
*/
void setJMSDeliveryTime(long deliveryTime) throws JMSException;
/**
* Gets the message priority level.
*
*
* The Jakarta Messaging 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 Jakarta Messaging 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.
*
* @return the default message priority
*
* @exception JMSException if the Jakarta Messaging provider fails to get the message priority due to some internal error.
*
* @see javax.jms.Message#setJMSPriority(int)
*/
int getJMSPriority() throws JMSException;
/**
* Sets the priority level for this message.
*
*
* This method is for use by Jakarta Messaging providers only to set this field when a message is sent. This message cannot be used by
* clients to configure the priority level of the message. This method is public to allow a Jakarta Messaging provider to set this
* field when sending a message whose implementation is not its own.
*
* @param priority the priority of this message
*
* @exception JMSException if the Jakarta Messaging provider fails to set the message priority due to some internal error.
*
* @see javax.jms.Message#getJMSPriority()
*/
void setJMSPriority(int priority) throws JMSException;
/**
* Clears a message's properties.
*
*
* The message's header fields and body are not cleared.
*
* @exception JMSException if the Jakarta Messaging provider fails to clear the message properties due to some internal error.
*/
void clearProperties() throws JMSException;
/**
* Indicates whether a property value exists.
*
* @param name the name of the property to test
*
* @return true if the property exists
*
* @exception JMSException if the Jakarta Messaging provider fails to determine if the property exists due to some internal error.
*/
boolean propertyExists(String name) throws JMSException;
/**
* Returns the value of the {@code boolean} property with the specified name.
*
* @param name the name of the {@code boolean} property
*
* @return the {@code boolean} property value for the specified name
*
* @exception JMSException if the Jakarta Messaging provider fails to get the property value due to some internal error.
* @exception MessageFormatException if this type conversion is invalid.
*/
boolean getBooleanProperty(String name) throws JMSException;
/**
* Returns the value of the {@code byte} property with the specified name.
*
* @param name the name of the {@code byte} property
*
* @return the {@code byte} property value for the specified name
*
* @exception JMSException if the Jakarta Messaging provider fails to get the property value due to some internal error.
* @exception MessageFormatException if this type conversion is invalid.
*/
byte getByteProperty(String name) throws JMSException;
/**
* Returns the value of the {@code short} property with the specified name.
*
* @param name the name of the {@code short} property
*
* @return the {@code short} property value for the specified name
*
* @exception JMSException if the Jakarta Messaging provider fails to get the property value due to some internal error.
* @exception MessageFormatException if this type conversion is invalid.
*/
short getShortProperty(String name) throws JMSException;
/**
* Returns the value of the {@code int} property with the specified name.
*
* @param name the name of the {@code int} property
*
* @return the {@code int} property value for the specified name
*
* @exception JMSException if the Jakarta Messaging provider fails to get the property value due to some internal error.
* @exception MessageFormatException if this type conversion is invalid.
*/
int getIntProperty(String name) throws JMSException;
/**
* Returns the value of the {@code long} property with the specified name.
*
* @param name the name of the {@code long} property
*
* @return the {@code long} property value for the specified name
*
* @exception JMSException if the Jakarta Messaging provider fails to get the property value due to some internal error.
* @exception MessageFormatException if this type conversion is invalid.
*/
long getLongProperty(String name) throws JMSException;
/**
* Returns the value of the {@code float} property with the specified name.
*
* @param name the name of the {@code float} property
*
* @return the {@code float} property value for the specified name
*
* @exception JMSException if the Jakarta Messaging provider fails to get the property value due to some internal error.
* @exception MessageFormatException if this type conversion is invalid.
*/
float getFloatProperty(String name) throws JMSException;
/**
* Returns the value of the {@code double} property with the specified name.
*
* @param name the name of the {@code double} property
*
* @return the {@code double} property value for the specified name
*
* @exception JMSException if the Jakarta Messaging provider fails to get the property value due to some internal error.
* @exception MessageFormatException if this type conversion is invalid.
*/
double getDoubleProperty(String name) throws JMSException;
/**
* Returns the value of the {@code String} property with the specified name.
*
* @param name the name of the {@code String} property
*
* @return the {@code String} property value for the specified name; if there is no property by this name, a null value
* is returned
*
* @exception JMSException if the Jakarta Messaging provider fails to get the property value due to some internal error.
* @exception MessageFormatException if this type conversion is invalid.
*/
String getStringProperty(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.
*
* @param name the name of the Java object property
*
* @return the Java object property value with the specified name, in objectified format (for example, if the property
* was set as an {@code int}, an {@code Integer} is returned); if there is no property by this name, a null value is
* returned
*
* @exception JMSException if the Jakarta Messaging provider fails to get the property value due to some internal error.
*/
Object getObjectProperty(String name) throws JMSException;
/**
* Returns an {@code Enumeration} of all the property names.
*
*
* Note that Jakarta Messaging standard header fields are not considered properties and are not returned in this enumeration.
*
* @return an enumeration of all the names of property values
*
* @exception JMSException if the Jakarta Messaging provider fails to get the property names due to some internal error.
*/
Enumeration getPropertyNames() throws JMSException;
/**
* Sets a {@code boolean} property value with the specified name into the message.
*
* @param name the name of the {@code boolean} property
* @param value the {@code boolean} property value to set
*
* @exception JMSException if the Jakarta Messaging provider fails to set the property due to some internal error.
* @exception IllegalArgumentException if the name is null or if the name is an empty string.
* @exception MessageNotWriteableException if properties are read-only
*/
void setBooleanProperty(String name, boolean value) throws JMSException;
/**
* Sets a {@code byte} property value with the specified name into the message.
*
* @param name the name of the {@code byte} property
* @param value the {@code byte} property value to set
*
* @exception JMSException if the Jakarta Messaging provider fails to set the property due to some internal error.
* @exception IllegalArgumentException if the name is null or if the name is an empty string.
* @exception MessageNotWriteableException if properties are read-only
*/
void setByteProperty(String name, byte value) throws JMSException;
/**
* Sets a {@code short} property value with the specified name into the message.
*
* @param name the name of the {@code short} property
* @param value the {@code short} property value to set
*
* @exception JMSException if the Jakarta Messaging provider fails to set the property due to some internal error.
* @exception IllegalArgumentException if the name is null or if the name is an empty string.
* @exception MessageNotWriteableException if properties are read-only
*/
void setShortProperty(String name, short value) throws JMSException;
/**
* Sets an {@code int} property value with the specified name into the message.
*
* @param name the name of the {@code int} property
* @param value the {@code int} property value to set
*
* @exception JMSException if the Jakarta Messaging provider fails to set the property due to some internal error.
* @exception IllegalArgumentException if the name is null or if the name is an empty string.
* @exception MessageNotWriteableException if properties are read-only
*/
void setIntProperty(String name, int value) throws JMSException;
/**
* Sets a {@code long} property value with the specified name into the message.
*
* @param name the name of the {@code long} property
* @param value the {@code long} property value to set
*
* @exception JMSException if the Jakarta Messaging provider fails to set the property due to some internal error.
* @exception IllegalArgumentException if the name is null or if the name is an empty string.
* @exception MessageNotWriteableException if properties are read-only
*/
void setLongProperty(String name, long value) throws JMSException;
/**
* Sets a {@code float} property value with the specified name into the message.
*
* @param name the name of the {@code float} property
* @param value the {@code float} property value to set
*
* @exception JMSException if the Jakarta Messaging provider fails to set the property due to some internal error.
* @exception IllegalArgumentException if the name is null or if the name is an empty string.
* @exception MessageNotWriteableException if properties are read-only
*/
void setFloatProperty(String name, float value) throws JMSException;
/**
* Sets a {@code double} property value with the specified name into the message.
*
* @param name the name of the {@code double} property
* @param value the {@code double} property value to set
*
* @exception JMSException if the Jakarta Messaging provider fails to set the property due to some internal error.
* @exception IllegalArgumentException if the name is null or if the name is an empty string.
* @exception MessageNotWriteableException if properties are read-only
*/
void setDoubleProperty(String name, double value) throws JMSException;
/**
* Sets a {@code String} property value with the specified name into the message.
*
* @param name the name of the {@code String} property
* @param value the {@code String} property value to set
*
* @exception JMSException if the Jakarta Messaging provider fails to set the property due to some internal error.
* @exception IllegalArgumentException if the name is null or if the name is an empty string.
* @exception MessageNotWriteableException if properties are read-only
*/
void setStringProperty(String name, String 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 ({@code Integer}, {@code Double},
* {@code Long} ...) and {@code String} objects.
*
* @param name the name of the Java object property
* @param value the Java object property value to set
*
* @exception JMSException if the Jakarta Messaging provider fails to set the property due to some internal error.
* @exception IllegalArgumentException if the name is null or if the name is an empty string.
* @exception MessageFormatException if the object is invalid
* @exception MessageNotWriteableException if properties are read-only
*/
void setObjectProperty(String name, Object value) throws JMSException;
/**
* Acknowledges all consumed messages of the session of this consumed message.
*
*
* All consumed Jakarta Messaging messages support the {@code acknowledge} method for use when a client has specified that its JMS
* session's consumed messages are to be explicitly acknowledged. By invoking {@code acknowledge} on a consumed message,
* a client acknowledges all messages consumed by the session that the message was delivered to.
*
*
* Calls to {@code 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.
*
* @exception JMSException if the Jakarta Messaging provider fails to acknowledge the messages due to some internal error.
* @exception IllegalStateException if this method is called on a closed session.
*
* @see javax.jms.Session#CLIENT_ACKNOWLEDGE
*/
void acknowledge() 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.
*
* @exception JMSException if the Jakarta Messaging provider fails to clear the message body due to some internal error.
*/
void clearBody() throws JMSException;
/**
* Returns the message body as an object of the specified type. This method may be called on any type of message except
* for StreamMessage. The message body must be capable of being assigned to the specified type. This means that
* the specified class or interface must be either the same as, or a superclass or superinterface of, the class of the
* message body. If the message has no body then any type may be specified and null is returned.
*
*
* @param The type of the message body
* @param c The type to which the message body will be assigned.
* If the message is a {@code TextMessage} then this parameter must be set to {@code String.class} or another type to
* which a {@code String} is assignable.
* If the message is a {@code ObjectMessage} then parameter must must be set to {@code java.io.Serializable.class} or
* another type to which the body is assignable.
* If the message is a {@code MapMessage} then this parameter must be set to {@code java.util.Map.class} (or
* {@code java.lang.Object.class}).
* If the message is a {@code BytesMessage} then this parameter must be set to {@code byte[].class} (or
* {@code java.lang.Object.class}). This method will reset the {@code BytesMessage} before and after use.
* If the message is a {@code TextMessage}, {@code ObjectMessage}, {@code MapMessage} or {@code BytesMessage} and the
* message has no body, then the above does not apply and this parameter may be set to any type; the returned value will
* always be null.
* If the message is a {@code Message} (but not one of its subtypes) then this parameter may be set to any type; the
* returned value will always be null.
*
* @return the message body
*
* @exception MessageFormatException
*
* - if the message is a {@code StreamMessage}
*
- if the message body cannot be assigned to the specified type
*
- if the message is an {@code ObjectMessage} and object deserialization fails.
*
*
* @exception JMSException if the Jakarta Messaging provider fails to get the message body due to some internal error.
*
* @since JMS 2.0
*/
T getBody(Class c) throws JMSException;
/**
* Returns whether the message body is capable of being assigned to the specified type. If this method returns true then
* a subsequent call to the method {@code getBody} on the same message with the same type argument would not throw a
* MessageFormatException.
*
* If the message is a {@code StreamMessage} then false is always returned. If the message is a {@code ObjectMessage}
* and object deserialization fails then false is returned. If the message has no body then any type may be specified
* and true is returned.
*
* @param c The specified type
* If the message is a {@code TextMessage} then this method will only return true if this parameter is set to
* {@code String.class} or another type to which a {@code String} is assignable.
* If the message is a {@code ObjectMessage} then this method will only return true if this parameter is set to
* {@code java.io.Serializable.class} or another class to which the body is assignable.
* If the message is a {@code MapMessage} then this method will only return true if this parameter is set to
* {@code java.util.Map.class} (or {@code java.lang.Object.class}).
* If the message is a {@code BytesMessage} then this this method will only return true if this parameter is set to
* {@code byte[].class} (or {@code java.lang.Object.class}).
* If the message is a {@code TextMessage}, {@code ObjectMessage}, {@code MapMessage} or {@code BytesMessage} and the
* message has no body, then the above does not apply and this method will return true irrespective of the value of this
* parameter.
* If the message is a {@code Message} (but not one of its subtypes) then this method will return true irrespective of
* the value of this parameter.
*
* @return whether the message body is capable of being assigned to the specified type
*
* @exception JMSException if the Jakarta Messaging provider fails to return a value due to some internal error.
*/
boolean isBodyAssignableTo(Class c) throws JMSException;
}