io.openmessaging.consumer

Interface PushConsumer

All Superinterfaces:

ServiceLifecycle

public interface PushConsumer
extends ServiceLifecycle

A PushConsumer receives messages from multiple queues, these messages are pushed from MOM server to PushConsumer client.

Since:

OMS 1.0.0

Version:

OMS 1.0.0

See Also:

MessagingAccessPoint.createPushConsumer()

Method Summary

Modifier and Type	Method and Description
void	addInterceptor(ConsumerInterceptor interceptor) Adds a ConsumerInterceptor instance to this consumer.
PushConsumer	attachQueue(String queueName, MessageListener listener) Attaches the PushConsumer to a specified queue, with a MessageListener.
PushConsumer	attachQueue(String queueName, MessageListener listener, KeyValue attributes) Attaches the PushConsumer to a specified queue, with a MessageListener and some specified attributes.
KeyValue	attributes() Returns the attributes of this PushConsumer instance.
PushConsumer	detachQueue(String queueName) Detaches the PushConsumer from a specified queue.
boolean	isSuspended() This method is used to find out whether the PushConsumer is suspended.
void	removeInterceptor(ConsumerInterceptor interceptor) Removes an interceptor from this consumer.
void	resume() Resumes the PushConsumer after a suspend.
void	suspend() Suspends the PushConsumer for later resumption.
void	suspend(long timeout) Suspends the PushConsumer for later resumption.

Methods inherited from interface io.openmessaging.ServiceLifecycle

shutdown, startup

Method Detail

attributes

KeyValue attributes()

Returns the attributes of this PushConsumer instance. Changes to the return KeyValue are not reflected in physical PushConsumer.

There are some standard attributes defined by OMS for PushConsumer:

• OMSBuiltinKeys.CONSUMER_ID, the unique consumer id for a consumer instance.
• OMSBuiltinKeys.OPERATION_TIMEOUT, the default timeout period for operations of PushConsumer.

Returns:

the attributes

resume

void resume()

Resumes the PushConsumer after a suspend.

This method resumes the PushConsumer instance after it was suspended. The instance will not receive new messages between the suspend and resume calls.

Throws:

OMSRuntimeException - if the instance has not been suspended.

See Also:

suspend()

suspend

void suspend()

Suspends the PushConsumer for later resumption.

This method suspends the consumer until it is resumed. The consumer will not receive new messages between the suspend and resume calls.

This method behaves exactly as if it simply performs the call suspend(0).

Throws:

OMSRuntimeException - if the instance is not currently running.

See Also:

resume()

suspend

void suspend(long timeout)

Suspends the PushConsumer for later resumption.

This method suspends the consumer until it is resumed or a specified amount of time has elapsed. The consumer will not receive new messages during the suspended state.

This method is similar to the suspend() method, but it allows finer control over the amount of time to suspend, and the consumer will be suspended until it is resumed if the timeout is zero.

Parameters:

timeout - the maximum time to suspend in milliseconds.

Throws:

OMSRuntimeException - if the instance is not currently running.

isSuspended

boolean isSuspended()

This method is used to find out whether the PushConsumer is suspended.

Returns:

true if this PushConsumer is suspended, false otherwise

attachQueue

PushConsumer attachQueue(String queueName,
                         MessageListener listener)

Attaches the PushConsumer to a specified queue, with a MessageListener.

MessageListener.onReceived(Message, MessageListener.Context) will be called when new delivered message is coming.

Parameters:

queueName - a specified queue

listener - a specified listener to receive new message

Returns:

this PushConsumer instance

attachQueue

PushConsumer attachQueue(String queueName,
                         MessageListener listener,
                         KeyValue attributes)

Attaches the PushConsumer to a specified queue, with a MessageListener and some specified attributes.

MessageListener.onReceived(Message, MessageListener.Context) will be called when new delivered message is coming.

Parameters:

queueName - a specified queue

listener - a specified listener to receive new message

attributes - some specified attributes

Returns:

this PushConsumer instance

detachQueue

PushConsumer detachQueue(String queueName)

Detaches the PushConsumer from a specified queue.

After the success call, this consumer won't receive new message from the specified queue any more.

Parameters:

queueName - a specified queue

Returns:

this PushConsumer instance

addInterceptor

void addInterceptor(ConsumerInterceptor interceptor)

Adds a ConsumerInterceptor instance to this consumer.

Parameters:

interceptor - an interceptor instance

removeInterceptor

void removeInterceptor(ConsumerInterceptor interceptor)

Removes an interceptor from this consumer.

Parameters:

interceptor - an interceptor to be removed