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/*
 * @(#)Message.java	1.60 02/04/09
 *
 * Copyright 1997-2002 Sun Microsystems, Inc. All Rights Reserved.
 *
 *  SUN PROPRIETARY/CONFIDENTIAL.
 * This software is the proprietary information of Sun Microsystems, Inc.  
 * Use is subject to license terms.
 * 
 */


package javax.jms;

import java.util.Enumeration;
import java.util.Properties;

/** 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: *

    *
  • 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 *
* *

JMS 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 JMS API defines several types of message body, which cover * the majority of messaging styles currently in use. *
* *

Message Bodies

* *

The JMS API defines five types of message body: *

    *
  • Stream - A 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 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. *
  • Text - A 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. *
  • Object - An ObjectMessage object's message body contains * a Serializable Java object. *
  • Bytes - A 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. *
* *

Message Headers

* *

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. * *

Message Properties

* *

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. * *

Provider Implementations of JMS Message Interfaces

* *

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. * *

Message Selectors

* *

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 * {@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 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, * 'literal' and '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 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. *
    • An approximate numeric literal is a numeric value in scientific * notation, such as 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. *
    • The boolean literals TRUE and 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 Character.isJavaLetter * returns true. This includes '_' and '$'. * A letter or digit is any character for which the method * Character.isJavaLetterOrDigit returns true. *
    • Identifiers cannot be the names NULL, * TRUE, and FALSE. *
    • Identifiers cannot be NOT, AND, * OR, BETWEEN, LIKE, * IN, IS, or 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 * 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 * JMSDeliveryMode, JMSPriority, * JMSMessageID, JMSTimestamp, * JMSCorrelationID, and JMSType. * JMSMessageID, JMSCorrelationID, and * JMSType values may be null and if so are treated as a * NULL value. *
    • Any name beginning with 'JMSX' is a JMS defined * property name. *
    • Any name beginning with 'JMS_' is a provider-specific * property name. *
    • Any name that does not begin with '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 true matches; a selector that evaluates to * 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 () for ordering expression evaluation * is supported. *
  • Logical operators in precedence order: NOT, * AND, OR *
  • Comparison operators: =, >, >=, * <, <=, <> (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" *
    • "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. * * @version 1.1 April 2, 2002 * @author Mark Hapner * @author Rich Burridge * @author Kate Stout * * @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 PERSISTENT. * * @see DeliveryMode#PERSISTENT */ static final int DEFAULT_DELIVERY_MODE = DeliveryMode.PERSISTENT; /** The message producer's default priority is 4. */ static final int DEFAULT_PRIORITY = 4; /** The message producer's default time to live is unlimited; the message * never expires. */ static final long DEFAULT_TIME_TO_LIVE = 0; /** 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. * * @return the message ID * * @exception JMSException if the JMS 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. * *

    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. * * @param id the ID of the message * * @exception JMSException if the JMS 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 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. * * @return the message timestamp * * @exception JMSException if the JMS 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. * *

    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. * * @param timestamp the timestamp for this message * * @exception JMSException if the JMS 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 byte[] value for * JMSCorrelationID is non-portable. * * @return the correlation ID of a message as an array of bytes * * @exception JMSException if the JMS 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 * 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. * * @param correlationID the correlation ID value as an array of bytes * * @exception JMSException if the JMS 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 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. * * @param correlationID the message ID of a message being referred to * * @exception JMSException if the JMS 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 * String values. * * @return the correlation ID of a message as a String * * @exception JMSException if the JMS 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 Destination object to which a reply to this * message should be sent. * * @return Destination to which to send a response to this * message * * @exception JMSException if the JMS provider fails to get the * JMSReplyTo destination due to some * internal error. * * @see javax.jms.Message#setJMSReplyTo(Destination) */ Destination getJMSReplyTo() 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. * * @param replyTo Destination to which to send a response to * this message * * @exception JMSException if the JMS provider fails to set the * JMSReplyTo destination due to some * internal error. * * @see javax.jms.Message#getJMSReplyTo() */ void setJMSReplyTo(Destination replyTo) 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. * * @return the destination of this message * * @exception JMSException if the JMS provider fails to get the destination * due to some internal error. * * @see javax.jms.Message#setJMSDestination(Destination) */ Destination getJMSDestination() 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. * * @param destination the destination for this message * * @exception JMSException if the JMS provider fails to set the destination * due to some internal error. * * @see javax.jms.Message#getJMSDestination() */ void setJMSDestination(Destination destination) throws JMSException; /** Gets the DeliveryMode value specified for this message. * * @return the delivery mode for this message * * @exception JMSException if the JMS 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 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. * * @param deliveryMode the delivery mode for this message * * @exception JMSException if the JMS 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 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 JMS 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 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. * * @param redelivered an indication of whether this message is being * redelivered * * @exception JMSException if the JMS 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 JMS 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 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. * * @param type the message type * * @exception JMSException if the JMS 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 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. * * @return 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 * * @exception JMSException if the JMS 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. * *

    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. * * @param expiration the message's expiration time * * @exception JMSException if the JMS 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 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. * * @return the default message priority * * @exception JMSException if the JMS 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. * *

    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. * * @param priority the priority of this message * * @exception JMSException if the JMS 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 JMS 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 JMS provider fails to determine if the * property exists due to some internal error. */ boolean propertyExists(String name) throws JMSException; /** Returns the value of the boolean property with the * specified name. * * @param name the name of the boolean property * * @return the boolean property value for the specified name * * @exception JMSException if the JMS 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 byte property with the specified * name. * * @param name the name of the byte property * * @return the byte property value for the specified name * * @exception JMSException if the JMS 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 short property with the specified * name. * * @param name the name of the short property * * @return the short property value for the specified name * * @exception JMSException if the JMS 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 int property with the specified * name. * * @param name the name of the int property * * @return the int property value for the specified name * * @exception JMSException if the JMS 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 long property with the specified * name. * * @param name the name of the long property * * @return the long property value for the specified name * * @exception JMSException if the JMS 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 float property with the specified * name. * * @param name the name of the float property * * @return the float property value for the specified name * * @exception JMSException if the JMS 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 double property with the specified * name. * * @param name the name of the double property * * @return the double property value for the specified name * * @exception JMSException if the JMS 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 String property with the specified * name. * * @param name the name of the String property * * @return the String property value for the specified name; * if there is no property by this name, a null value is returned * * @exception JMSException if the JMS 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 * int, an Integer is * returned); if there is no property by this name, a null value * is returned * * @exception JMSException if the JMS provider fails to get the property * value due to some internal error. */ Object getObjectProperty(String name) 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. * * @return an enumeration of all the names of property values * * @exception JMSException if the JMS provider fails to get the property * names due to some internal error. */ Enumeration getPropertyNames() throws JMSException; /** Sets a boolean property value with the specified name into * the message. * * @param name the name of the boolean property * @param value the boolean property value to set * * @exception JMSException if the JMS 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 byte property value with the specified name into * the message. * * @param name the name of the byte property * @param value the byte property value to set * * @exception JMSException if the JMS 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 short property value with the specified name into * the message. * * @param name the name of the short property * @param value the short property value to set * * @exception JMSException if the JMS 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 int property value with the specified name into * the message. * * @param name the name of the int property * @param value the int property value to set * * @exception JMSException if the JMS 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 long property value with the specified name into * the message. * * @param name the name of the long property * @param value the long property value to set * * @exception JMSException if the JMS 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 float property value with the specified name into * the message. * * @param name the name of the float property * @param value the float property value to set * * @exception JMSException if the JMS 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 double property value with the specified name into * the message. * * @param name the name of the double property * @param value the double property value to set * * @exception JMSException if the JMS 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 String property value with the specified name into * the message. * * @param name the name of the String property * @param value the String property value to set * * @exception JMSException if the JMS 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 (Integer, Double, * Long ...) and String objects. * * @param name the name of the Java object property * @param value the Java object property value to set * * @exception JMSException if the JMS 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 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. * * @exception JMSException if the JMS 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 JMS provider fails to clear the message * body due to some internal error. */ void clearBody() throws JMSException; }





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