Top Description Methods
javax.jms

public Interface JMSConsumer

extends AutoCloseable
A client using the simplified JMS API introduced for JMS 2.0 uses a JMSConsumer object to receive messages from a queue or topic. A JMSConsumer object may be created either created by passing a Queue or Topic object to one of the createConsumer methods on a JMSContext. or by passing a Topic object to one of the createSharedConsumer or createDurableConsumer methods on a JMSContext.

A JMSConsumer can be created with a message selector. A message selector allows the client to restrict the messages delivered to the JMSConsumer to those that match the selector.

A client may either synchronously receive a JMSConsumer's messages or have the JMSConsumer asynchronously deliver them as they arrive.

For synchronous receipt, a client can request the next message from a JMSConsumer using one of its receive methods. There are several variations of receive that allow a client to poll or wait for the next message.

For asynchronous delivery, a client can register a MessageListener object with a JMSConsumer. As messages arrive at the JMSConsumer, it delivers them by calling the MessageListener 's onMessage method.

It is a client programming error for a MessageListener to throw an exception.

Since
JMS 2.0
Version
JMS 2.0
See Also
javax.jms.JMSContext

Method Summary

Modifier and TypeMethod and Description
public void
close()

Redeclares java.lang.AutoCloseable.close.

Closes the JMSConsumer.
public MessageListener

Returns:

the JMSConsumer's MessageListener, or null if one was not set
getMessageListener()

Gets the JMSConsumer's MessageListener.

public String

Returns:

this JMSConsumer's message selector, or null if no message selector exists for the JMSConsumer (that is, if the message selector was not set or was set to null or the empty string)
getMessageSelector()

Gets this JMSConsumer's message selector expression.

public Message

Returns:

the next message produced for this JMSConsumer, or null if this JMSConsumer is concurrently closed
receive()

Receives the next message produced for this JMSConsumer.

public Message

Returns:

the next message produced for this JMSConsumer, or null if the timeout expires or this JMSConsumer is concurrently closed
receive(long
the timeout value (in milliseconds)
timeout)

Receives the next message that arrives within the specified timeout interval.

public <T> T

Returns:

the body of the next message produced for this JMSConsumer, or null if this JMSConsumer is concurrently closed
receiveBody(Class<T>
The type to which the body of the next message should be assigned.
If the next message is expected to be a TextMessage then this should be set to String.class or another class to which a String is assignable.
If the next message is expected to be a ObjectMessage then this should be set to java.io.Serializable.class or another class to which the body is assignable.
If the next message is expected to be a MapMessage then this should be set to java.util.Map.class (or java.lang.Object.class).
If the next message is expected to be a BytesMessage then this should be set to byte[].class (or java.lang.Object.class).
c)

Receives the next message produced for this JMSConsumer and returns its body as an object of the specified type.

public <T> T

Returns:

the body of the next message produced for this JMSConsumer, or null if the timeout expires or this JMSConsumer is concurrently closed
receiveBody(Class<T>
The type to which the body of the next message should be assigned.
If the next message is expected to be a TextMessage then this should be set to String.class or another class to which a String is assignable.
If the next message is expected to be a ObjectMessage then this should be set to java.io.Serializable.class or another class to which the body is assignable.
If the next message is expected to be a MapMessage then this should be set to java.util.Map.class (or java.lang.Object.class).
If the next message is expected to be a BytesMessage then this should be set to byte[].class (or java.lang.Object.class).
c, long timeout)

Receives the next message produced for this JMSConsumer that arrives within the specified timeout period and returns its body as an object of the specified type.

public <T> T

Returns:

the body of the next message produced for this JMSConsumer, or null if one is not immediately available or this JMSConsumer is concurrently closed
receiveBodyNoWait(Class<T>
The type to which the body of the next message should be assigned.
If the next message is expected to be a TextMessage then this should be set to String.class or another class to which a String is assignable.
If the next message is expected to be a ObjectMessage then this should be set to java.io.Serializable.class or another class to which the body is assignable.
If the next message is expected to be a MapMessage then this should be set to java.util.Map.class (or java.lang.Object.class).
If the next message is expected to be a BytesMessage then this should be set to byte[].class (or java.lang.Object.class).
c)

Receives the next message produced for this JMSConsumer if one is immediately available and returns its body as an object of the specified type.

public Message

Returns:

the next message produced for this JMSConsumer, or null if one is not available
receiveNoWait()

Receives the next message if one is immediately available.

public void
setMessageListener(MessageListener
the listener to which the messages are to be delivered
listener)

Sets the JMSConsumer's MessageListener.

Method Detail

closeback to summary
public void close()

Redeclares java.lang.AutoCloseable.close.

Closes the JMSConsumer.

Since a provider may allocate some resources on behalf of a JMSConsumer outside the Java virtual machine, clients should close them when they are not needed. Relying on garbage collection to eventually reclaim these resources may not be timely enough.

This call will block until a receive call in progress on this consumer has completed. A blocked receive call returns null when this consumer is closed.

If this method is called whilst a message listener is in progress in another thread then it will block until the message listener has completed.

This method may be called from a message listener's onMessage method on its own consumer. After this method returns the onMessage method will be allowed to complete normally.

This method is the only JMSConsumer method that can be called concurrently.

Exceptions
JMSRuntimeException:
if the JMS provider fails to close the consumer due to some internal error.
getMessageListenerback to summary
public MessageListener getMessageListener() throws JMSRuntimeException

Gets the JMSConsumer's MessageListener.

This method must not be used in a Java EE web or EJB application. Doing so may cause a JMSRuntimeException to be thrown though this is not guaranteed.

Returns:MessageListener

the JMSConsumer's MessageListener, or null if one was not set

Exceptions
JMSRuntimeException:
if the JMS provider fails to get the MessageListener for one of the following reasons:
  • an internal error has occurred or
  • this method has been called in a Java EE web or EJB application (though it is not guaranteed that an exception is thrown in this case)
See Also
javax.jms.JMSConsumer#setMessageListener(javax.jms.MessageListener)
getMessageSelectorback to summary
public String getMessageSelector()

Gets this JMSConsumer's message selector expression.

Returns:String

this JMSConsumer's message selector, or null if no message selector exists for the JMSConsumer (that is, if the message selector was not set or was set to null or the empty string)

Exceptions
JMSRuntimeException:
if the JMS provider fails to get the message selector due to some internal error.
receiveback to summary
public Message receive()

Receives the next message produced for this JMSConsumer.

This call blocks indefinitely until a message is produced or until this JMSConsumer is closed.

If this receive is done within a transaction, the JMSConsumer retains the message until the transaction commits.

Returns:Message

the next message produced for this JMSConsumer, or null if this JMSConsumer is concurrently closed

Exceptions
JMSRuntimeException:
if the JMS provider fails to receive the next message due to some internal error.
receiveback to summary
public Message receive(long timeout)

Receives the next message that arrives within the specified timeout interval.

This call blocks until a message arrives, the timeout expires, or this JMSConsumer is closed. A timeout of zero never expires, and the call blocks indefinitely.

Parameters
timeout:long

the timeout value (in milliseconds)

Returns:Message

the next message produced for this JMSConsumer, or null if the timeout expires or this JMSConsumer is concurrently closed

Exceptions
JMSRuntimeException:
if the JMS provider fails to receive the next message due to some internal error.
receiveBodyback to summary
public <T> T receiveBody(Class<T> c)

Receives the next message produced for this JMSConsumer and returns its body as an object of the specified type. This method may be used to receive any type of message except for StreamMessage and Message, so long as the message has a body which is capable of being assigned to the specified type. This means that the specified class or interface must either be the same as, or a superclass or superinterface of, the class of the message body. If the message is not one of the supported types, or its body cannot be assigned to the specified type, or it has no body, then a MessageFormatRuntimeException is thrown.

This method does not give access to the message headers or properties (such as the JMSRedelivered message header field or the JMSXDeliveryCount message property) and should only be used if the application has no need to access them.

This call blocks indefinitely until a message is produced or until this JMSConsumer is closed.

If this method is called within a transaction, the JMSConsumer retains the message until the transaction commits.

The result of this method throwing a MessageFormatRuntimeException depends on the session mode:

  • AUTO_ACKNOWLEDGE or DUPS_OK_ACKNOWLEDGE: The JMS provider will behave as if the unsuccessful call to receiveBody had not occurred. The message will be delivered again before any subsequent messages.

    This is not considered to be redelivery and does not cause the JMSRedelivered message header field to be set or the JMSXDeliveryCount message property to be incremented.

  • CLIENT_ACKNOWLEDGE: The JMS provider will behave as if the call to receiveBody had been successful and will not deliver the message again.

    As with any message that is delivered with a session mode of CLIENT_ACKNOWLEDGE, the message will not be acknowledged until acknowledge is called on the JMSContext. If an application wishes to have the failed message redelivered, it must call recover on the JMSContext. The redelivered message's JMSRedelivered message header field will be set and its JMSXDeliveryCount message property will be incremented.

  • Transacted session: The JMS provider will behave as if the call to receiveBody had been successful and will not deliver the message again.

    As with any message that is delivered in a transacted session, the transaction will remain uncommitted until the transaction is committed or rolled back by the application. If an application wishes to have the failed message redelivered, it must roll back the transaction. The redelivered message's JMSRedelivered message header field will be set and its JMSXDeliveryCount message property will be incremented.

Parameters
c:Class<T>

The type to which the body of the next message should be assigned.
If the next message is expected to be a TextMessage then this should be set to String.class or another class to which a String is assignable.
If the next message is expected to be a ObjectMessage then this should be set to java.io.Serializable.class or another class to which the body is assignable.
If the next message is expected to be a MapMessage then this should be set to java.util.Map.class (or java.lang.Object.class).
If the next message is expected to be a BytesMessage then this should be set to byte[].class (or java.lang.Object.class).

Returns:T

the body of the next message produced for this JMSConsumer, or null if this JMSConsumer is concurrently closed

Exceptions
MessageFormatRuntimeException:
  • if the message is not one of the supported types listed above
  • if the message body cannot be assigned to the specified type
  • if the message has no body
  • if the message is an ObjectMessage and object deserialization fails.
JMSRuntimeException:
if the JMS provider fails to receive the next message due to some internal error
receiveBodyback to summary
public <T> T receiveBody(Class<T> c, long timeout)

Receives the next message produced for this JMSConsumer that arrives within the specified timeout period and returns its body as an object of the specified type. This method may be used to receive any type of message except for StreamMessage and Message, so long as the message has a body which is capable of being assigned to the specified type. This means that the specified class or interface must either be the same as, or a superclass or superinterface of, the class of the message body. If the message is not one of the supported types, or its body cannot be assigned to the specified type, or it has no body, then a MessageFormatRuntimeException is thrown.

This method does not give access to the message headers or properties (such as the JMSRedelivered message header field or the JMSXDeliveryCount message property) and should only be used if the application has no need to access them.

This call blocks until a message arrives, the timeout expires, or this JMSConsumer is closed. A timeout of zero never expires, and the call blocks indefinitely.

If this method is called within a transaction, the JMSConsumer retains the message until the transaction commits.

The result of this method throwing a MessageFormatRuntimeException depends on the session mode:

  • AUTO_ACKNOWLEDGE or DUPS_OK_ACKNOWLEDGE: The JMS provider will behave as if the unsuccessful call to receiveBody had not occurred. The message will be delivered again before any subsequent messages.

    This is not considered to be redelivery and does not cause the JMSRedelivered message header field to be set or the JMSXDeliveryCount message property to be incremented.

  • CLIENT_ACKNOWLEDGE: The JMS provider will behave as if the call to receiveBody had been successful and will not deliver the message again.

    As with any message that is delivered with a session mode of CLIENT_ACKNOWLEDGE, the message will not be acknowledged until acknowledge is called on the JMSContext. If an application wishes to have the failed message redelivered, it must call recover on the JMSContext. The redelivered message's JMSRedelivered message header field will be set and its JMSXDeliveryCount message property will be incremented.

  • Transacted session: The JMS provider will behave as if the call to receiveBody had been successful and will not deliver the message again.

    As with any message that is delivered in a transacted session, the transaction will remain uncommitted until the transaction is committed or rolled back by the application. If an application wishes to have the failed message redelivered, it must roll back the transaction. The redelivered message's JMSRedelivered message header field will be set and its JMSXDeliveryCount message property will be incremented.

Parameters
c:Class<T>

The type to which the body of the next message should be assigned.
If the next message is expected to be a TextMessage then this should be set to String.class or another class to which a String is assignable.
If the next message is expected to be a ObjectMessage then this should be set to java.io.Serializable.class or another class to which the body is assignable.
If the next message is expected to be a MapMessage then this should be set to java.util.Map.class (or java.lang.Object.class).
If the next message is expected to be a BytesMessage then this should be set to byte[].class (or java.lang.Object.class).

Returns:T

the body of the next message produced for this JMSConsumer, or null if the timeout expires or this JMSConsumer is concurrently closed

Exceptions
MessageFormatRuntimeException:
  • if the message is not one of the supported types listed above
  • if the message body cannot be assigned to the specified type
  • if the message has no body
  • if the message is an ObjectMessage and object deserialization fails.
JMSRuntimeException:
if the JMS provider fails to receive the next message due to some internal error
receiveBodyNoWaitback to summary
public <T> T receiveBodyNoWait(Class<T> c)

Receives the next message produced for this JMSConsumer if one is immediately available and returns its body as an object of the specified type. This method may be used to receive any type of message except for StreamMessage and Message, so long as the message has a body which is capable of being assigned to the specified type. This means that the specified class or interface must either be the same as, or a superclass or superinterface of, the class of the message body. If the message is not one of the supported types, or its body cannot be assigned to the specified type, or it has no body, then a MessageFormatRuntimeException is thrown.

This method does not give access to the message headers or properties (such as the JMSRedelivered message header field or the JMSXDeliveryCount message property) and should only be used if the application has no need to access them.

If a message is not immediately available null is returned.

If this method is called within a transaction, the JMSConsumer retains the message until the transaction commits.

The result of this method throwing a MessageFormatRuntimeException depends on the session mode:

  • AUTO_ACKNOWLEDGE or DUPS_OK_ACKNOWLEDGE: The JMS provider will behave as if the unsuccessful call to receiveBodyNoWait had not occurred. The message will be delivered again before any subsequent messages.

    This is not considered to be redelivery and does not cause the JMSRedelivered message header field to be set or the JMSXDeliveryCount message property to be incremented.

  • CLIENT_ACKNOWLEDGE: The JMS provider will behave as if the call to receiveBodyNoWait had been successful and will not deliver the message again.

    As with any message that is delivered with a session mode of CLIENT_ACKNOWLEDGE, the message will not be acknowledged until acknowledge is called on the JMSContext. If an application wishes to have the failed message redelivered, it must call recover on the JMSContext. The redelivered message's JMSRedelivered message header field will be set and its JMSXDeliveryCount message property will be incremented.

  • Transacted session: The JMS provider will behave as if the call to receiveBodyNoWait had been successful and will not deliver the message again.

    As with any message that is delivered in a transacted session, the transaction will remain uncommitted until the transaction is committed or rolled back by the application. If an application wishes to have the failed message redelivered, it must roll back the transaction. The redelivered message's JMSRedelivered message header field will be set and its JMSXDeliveryCount message property will be incremented.

Parameters
c:Class<T>

The type to which the body of the next message should be assigned.
If the next message is expected to be a TextMessage then this should be set to String.class or another class to which a String is assignable.
If the next message is expected to be a ObjectMessage then this should be set to java.io.Serializable.class or another class to which the body is assignable.
If the next message is expected to be a MapMessage then this should be set to java.util.Map.class (or java.lang.Object.class).
If the next message is expected to be a BytesMessage then this should be set to byte[].class (or java.lang.Object.class).

Returns:T

the body of the next message produced for this JMSConsumer, or null if one is not immediately available or this JMSConsumer is concurrently closed

Exceptions
MessageFormatRuntimeException:
  • if the message is not one of the supported types listed above
  • if the message body cannot be assigned to the specified type
  • if the message has no body
  • if the message is an ObjectMessage and object deserialization fails.
JMSRuntimeException:
if the JMS provider fails to receive the next message due to some internal error
receiveNoWaitback to summary
public Message receiveNoWait()

Receives the next message if one is immediately available.

Returns:Message

the next message produced for this JMSConsumer, or null if one is not available

Exceptions
JMSRuntimeException:
if the JMS provider fails to receive the next message due to some internal error.
setMessageListenerback to summary
public void setMessageListener(MessageListener listener) throws JMSRuntimeException

Sets the JMSConsumer's MessageListener.

Setting the MessageListener to null is the equivalent of unsetting the MessageListener for the JMSConsumer.

The effect of calling this method while messages are being consumed by an existing listener or the JMSConsumer is being used to consume messages synchronously is undefined.

This method must not be used in a Java EE web or EJB application. Doing so may cause a JMSRuntimeException to be thrown though this is not guaranteed.

Parameters
listener:MessageListener

the listener to which the messages are to be delivered

Exceptions
JMSRuntimeException:
if the JMS provider fails to set the JMSConsumer's MessageListener for one of the following reasons:
  • an internal error has occurred or
  • this method has been called in a Java EE web or EJB application (though it is not guaranteed that an exception is thrown in this case)
See Also
javax.jms.JMSConsumer#getMessageListener()