Package org.javalite.async

Class Async

java.lang.Object

org.javalite.async.Async

public class Async
extends Object

Wrapper for embedded Apache ActiveMQ Artemis. It is an embedded in-memory JMS server for asynchronous processing. JavaLite Async can be used in standalone applications, but specifically useful in web apps for processing asynchronous jobs without delaying rendering web responses. It sets many configuration parameters of Artemis EmbeddedActiveMQ to sensible values so you do not have to. This class also implements a Command Pattern for ease of writing asynchronous code.

Author:

Igor Polevoy on 3/4/15.

Constructor Summary

Constructors

Constructor	Description
Async(String dataDirectory, boolean useLibAio, com.google.inject.Injector injector, QueueConfig... queueConfigs)	Creates and configures a new instance.
Async(String dataDirectory, boolean useLibAio, QueueConfig... queueConfigs)	Creates and configures a new instance.

Method Summary

Modifier and Type	Method	Description
void	configureNetty(String host, int port)	Call this method once after a constructor in order to create a Netty instance to accept out of VM messages.
BatchReceiver	getBatchReceiver(String queueName, long timeout)	Generate a BatchReceiver to receive and process stored messages.
static byte[]	getBytes(javax.jms.BytesMessage message)
org.apache.activemq.artemis.core.config.Configuration	getConfig()	Get additional server configuration.
long	getMessageCount(String queue)	Returns number of messages currently in queue
Map<String,Long>	getMessageCounts()	Returns counts of messages for all queues.
List<Command>	getTopCommands(int count, String queueName)	Returns top commands in queue.
List<String>	getTopTextMessages(int maxSize, String queueName)	Returns top TextMessages in queue.
boolean	isPaused(String queueName)
boolean	moveMessage(String jmsMessageId, String source, String target)	Moves a message from one queue to another
int	moveMessages(String source, String target)	Moves all messages from one queue to another
void	pause(String queueName)	Pauses a queue.
Command	receiveCommand(String queueName)	Receives a command from a queue synchronously.
<T extends Command> T	receiveCommand(String queueName, int timeout, Class<T> type)	Receives a command from a queue synchronously.
Command	receiveCommand(String queueName, long timeout)	Receives a command from a queue synchronously.
<T extends Command> T	receiveCommand(String queueName, Class<T> type)	Receives a command from a queue synchronously.
javax.jms.Message	receiveMessage(String queueName, long timeout)	Receives a messafge from a queue asynchronously.If this queue also has listeners, then messages will be distributed across all consumers.
int	removeAllMessages(String queueName)	Removes all messages from queue.
int	removeMessages(String queueName, String filter)	Removes messages from queue.
void	resume(String queueName)	Resumes a paused queue
void	send(String queueName, Command command)	Sends a command into a queue for processing
void	send(String queueName, Command command, int deliveryMode)	Sends a command into a queue for processing
void	send(String queueName, Command command, int deliveryMode, int priority, long timeToLive)	Sends a command into a queue for processing
void	send(String queueName, Command command, int deliveryMode, int priority, long timeToLive, long deliveryTime)	Sends a command into a queue for processing
void	send(String queueName, Command command, int deliveryMode, long deliveryTime)	Sends a command into a queue for processing
void	send(String queueName, Command command, Date deliveryTime)	Sends a command into a queue for processing
void	sendTextMessage(String queueName, String text)	Sends a non-expiring TextMessage with average priority.
void	sendTextMessage(String queueName, String text, int deliveryMode, int priority, long timeToLive)	Sends a TextMessage.
void	sendTextMessage(String queueName, String text, int deliveryMode, int priority, long timeToLive, long deliveryTime)	Sends a TextMessage.
void	sendTextMessage(String queueName, String text, long deliveryTime)	Sends a non-expiring TextMessage with average priority.
void	setBinaryMode(boolean binaryMode)	If true, uses binary mode to send messages.
void	start()	Starts the server.
void	stop()	Stops this JMS server.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Async

public Async(String dataDirectory,
             boolean useLibAio,
             QueueConfig... queueConfigs)

Creates and configures a new instance.

Parameters:

dataDirectory - root directory where persistent messages are stored

useLibAio - true to use libaio, false not to use (See Artemis log statements to check if it was detected).

queueConfigs - vararg of QueueConfig instances.

Async

public Async(String dataDirectory,
             boolean useLibAio,
             com.google.inject.Injector injector,
             QueueConfig... queueConfigs)

Creates and configures a new instance.

Parameters:

dataDirectory - root directory where persistent messages are stored

useLibAio - true to use libaio, false to use NIO.

injector - Google Guice injector. Used to inject dependency members into commands if needed.

queueConfigs - vararg of QueueConfig> instances.

Method Detail

start

public void start()

Starts the server.

stop

public void stop()

Stops this JMS server.

setBinaryMode

public void setBinaryMode(boolean binaryMode)

If true, uses binary mode to send messages. If set to false (default), will send messages as strings. Test which method is faster in your environment for your CPU and IO performance. generally, binary mode will use a lot less IO, but more CPU and vice versa.

Parameters:

binaryMode - true to send messages in binary mode, false to send as strings.

configureNetty

public void configureNetty(String host,
                           int port)

Call this method once after a constructor in order to create a Netty instance to accept out of VM messages.

Parameters:

host - host to bind to

port - port to listen on

send

public void send(String queueName,
                 Command command)

Sends a command into a queue for processing

Parameters:

queueName - name of queue

command - command instance.

send

public void send(String queueName,
                 Command command,
                 Date deliveryTime)

Sends a command into a queue for processing

Parameters:

queueName - name of queue

command - command instance.

deliveryTime - delivery time in the future. If null, or in the past, the message will be delivered as usual.

send

public void send(String queueName,
                 Command command,
                 int deliveryMode)

Sends a command into a queue for processing

Parameters:

queueName - name of queue

command - command to process

deliveryMode - delivery mode: DeliveryMode.

send

public void send(String queueName,
                 Command command,
                 int deliveryMode,
                 long deliveryTime)

Sends a command into a queue for processing

Parameters:

queueName - name of queue

command - command to process

deliveryMode - delivery mode: DeliveryMode.

deliveryTime - delivery time in milliseconds

send

public void send(String queueName,
                 Command command,
                 int deliveryMode,
                 int priority,
                 long timeToLive)

Sends a command into a queue for processing

Parameters:

queueName - name of queue

command - command to process

deliveryMode - delivery mode: DeliveryMode.

priority - priority of the message. Correct values are from 0 to 9, with higher number denoting a higher priority.

timeToLive - the message's lifetime (in milliseconds, where 0 is to never expire)

send

public void send(String queueName,
                 Command command,
                 int deliveryMode,
                 int priority,
                 long timeToLive,
                 long deliveryTime)

Sends a command into a queue for processing

Parameters:

queueName - name of queue

command - command to process

deliveryMode - delivery mode: DeliveryMode. 1 for non-persistent, 2 for persistent.

priority - priority of the message. Correct values are from 0 to 9, with higher number denoting a higher priority.

timeToLive - the message's lifetime (in milliseconds, where 0 is to never expire)

deliveryTime - The specified value must be a positive long corresponding to the time the message must be delivered (in milliseconds). For instance, System.currentTimeMillis() + 5000 would be 5 seconds from now.

receiveCommand

public Command receiveCommand(String queueName)

Receives a command from a queue synchronously. If this queue also has listeners, then commands will be distributed across all consumers.

Parameters:

queueName - name of queue

Returns:

command if found. If command not found, this method will block till a command is present in queue. see receiveCommand(String, long)

receiveCommand

public <T extends Command> T receiveCommand(String queueName,
                                            Class<T> type)

Receives a command from a queue synchronously. If this queue also has listeners, then commands will be distributed across all consumers. This method will block until a command becomes available for this consumer.

Parameters:

queueName - name of queue

type - expected class of a command

Returns:

command if found. If command not found, this method will block till a command is present in queue. see receiveCommand(String, long)

receiveCommand

public <T extends Command> T receiveCommand(String queueName,
                                            int timeout,
                                            Class<T> type)

Receives a command from a queue synchronously. If this queue also has listeners, then commands will be distributed across all consumers.

Parameters:

queueName - name of queue

timeout - timeout in milliseconds. If a command is not received during a timeout, this methods returns null.

type - expected class of a command

Returns:

command if found. If command not found, this method will block till a command is present in queue. see receiveCommand(String, long)

receiveCommand

public Command receiveCommand(String queueName,
                              long timeout)

Receives a command from a queue synchronously. If this queue also has listeners, then commands will be distributed across all consumers.

Parameters:

queueName - name of queue

timeout - timeout in milliseconds. If a command is not received during a timeout, this methods returns null.

Returns:

command if found. If command not found, this method will block till a command is present in queue or a timeout expires.

receiveMessage

public javax.jms.Message receiveMessage(String queueName,
                                        long timeout)

Receives a messafge from a queue asynchronously.If this queue also has listeners, then messages will be distributed across all consumers.

Parameters:

queueName - name of queue

timeout - timeout in millis.

Returns:

message if found, null if not.

sendTextMessage

public void sendTextMessage(String queueName,
                            String text)

Sends a non-expiring TextMessage with average priority.

Parameters:

queueName - name of queue

text - body of message

sendTextMessage

public void sendTextMessage(String queueName,
                            String text,
                            long deliveryTime)

Sends a non-expiring TextMessage with average priority.

Parameters:

queueName - name of queue

text - body of message

deliveryTime - The specified value must be a positive long corresponding to the time the message must be delivered (in milliseconds). For instance, System.currentTimeMillis() + 5000 would be 5 seconds from now.

sendTextMessage

public void sendTextMessage(String queueName,
                            String text,
                            int deliveryMode,
                            int priority,
                            long timeToLive)

Sends a TextMessage.

Parameters:

queueName - name of queue

text - body of message

deliveryMode - delivery mode: DeliveryMode.

priority - priority of the message. Correct values are from 0 to 9, with higher number denoting a higher priority.

timeToLive - the message's lifetime (in milliseconds, where 0 is to never expire)

sendTextMessage

public void sendTextMessage(String queueName,
                            String text,
                            int deliveryMode,
                            int priority,
                            long timeToLive,
                            long deliveryTime)

Sends a TextMessage.

Parameters:

queueName - name of queue

text - body of message

deliveryMode - delivery mode: DeliveryMode.

priority - priority of the message. Correct values are from 0 to 9, with higher number denoting a higher priority.

timeToLive - the message's lifetime (in milliseconds, where 0 is to never expire)

deliveryTime - The specified value must be a positive long corresponding to the time the message must be delivered (in milliseconds). For instance, System.currentTimeMillis() + 5000 would be 5 seconds from now.

getBatchReceiver

public BatchReceiver getBatchReceiver(String queueName,
                                      long timeout)

Generate a BatchReceiver to receive and process stored messages. This method ALWAYS works in the context of a transaction.

Parameters:

queueName - name of queue

timeout - timeout to wait.

Returns:

instance of BatchReceiver.

getTopCommands

public List<Command> getTopCommands(int count,
                                    String queueName)

Returns top commands in queue. Does not remove anything from queue. This method can be used for an admin tool to peek inside the queue.

Parameters:

count - number of commands to lookup.

Returns:

top commands in queue or empty list is nothing is found in queue.

getTopTextMessages

public List<String> getTopTextMessages(int maxSize,
                                       String queueName)

Returns top TextMessages in queue. Does not remove anything from queue. This method can be used for an admin tool to peek inside the queue.

Parameters:

maxSize - max number of messages to lookup.

Returns:

top commands in queue or empty list is nothing is found in queue.

getBytes

public static byte[] getBytes(javax.jms.BytesMessage message)
                       throws javax.jms.JMSException

Throws:

javax.jms.JMSException

getMessageCounts

public Map<String,Long> getMessageCounts()

Returns counts of messages for all queues.

Returns:

map, where a key is a queue name, and value is a number of messages currently in that queue.0

getMessageCount

public long getMessageCount(String queue)

Returns number of messages currently in queue

Parameters:

queue - queue name

Returns:

number of messages currently in queue

resume

public void resume(String queueName)

Resumes a paused queue

Parameters:

queueName - queue name

pause

public void pause(String queueName)

Pauses a queue. A paused queue stops delivering commands to listeners. It still can accumulate commands.

Parameters:

queueName - queue name.

isPaused

public boolean isPaused(String queueName)

Parameters:

queueName - queue name

Returns:

true if queue is paused, false if not.

removeMessages

public int removeMessages(String queueName,
                          String filter)

Removes messages from queue.

Parameters:

queueName - queue name

filter - filter selector as in JMS specification. See: JMS Message Selectors

Returns:

number of messages removed

removeAllMessages

public int removeAllMessages(String queueName)

Removes all messages from queue.

Parameters:

queueName - queue name.

Returns:

number of messages removed

moveMessages

public int moveMessages(String source,
                        String target)

Moves all messages from one queue to another

Parameters:

source - name of source queue

target - name of target queue

Returns:

number of messages moved

moveMessage

public boolean moveMessage(String jmsMessageId,
                           String source,
                           String target)

Moves a message from one queue to another

Parameters:

jmsMessageId - JMS message id of a message to move

source - name of source queue

target - name of target queue

Returns:

true if message moved

getConfig

public org.apache.activemq.artemis.core.config.Configuration getConfig()

Get additional server configuration.