Async (JavaLite - Java, light as a feather 2.3.1-j8-SNAPSHOT API)

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 EmbeddedJMS 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 and 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

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and 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.
`org.apache.activemq.artemis.jms.server.config.JMSConfiguration`	`getJmsConfig()` Get additional JMS 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 `TextMessage`s in queue.
`boolean`	`isPaused(String queueName)`
`protected javax.jms.Message`	`lookupMessage(String queueName)` This method exists for testing
`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, Class<T> type)` 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.
`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, int timeToLive)` 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, int timeToLive)` Sends a `TextMessage`.
`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,
                 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,
                 int priority,
                 int 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)
  - 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 Also:
    
    #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 Also:
    
    #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 Also:
    
    #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,
                            int deliveryMode,
                            int priority,
                            int 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)
  - 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.
  - lookupMessage
```
protected javax.jms.Message lookupMessage(String queueName)
```
    This method exists for testing
  - 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
  - getJmsConfig
```
public org.apache.activemq.artemis.jms.server.config.JMSConfiguration getJmsConfig()
```
    Get additional JMS configuration.
  - getConfig
```
public org.apache.activemq.artemis.core.config.Configuration getConfig()
```
    Get additional server configuration.

Class Async

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

Async

Async

Method Detail

start

stop

setBinaryMode

configureNetty

send

send

send

receiveCommand

receiveCommand

receiveCommand

receiveCommand

receiveMessage

sendTextMessage

sendTextMessage

getBatchReceiver

getTopCommands

getTopTextMessages

lookupMessage

getBytes

getMessageCounts

getMessageCount

resume

pause

isPaused

removeMessages

removeAllMessages

moveMessages

moveMessage

getJmsConfig

getConfig