The Quartz transport provides support for scheduling events and for triggering new events. An inbound quartz endpoint can be used to trigger inbound events that can be repeated, such as every second. Outbound quartz endpoints can be used to schedule an existing event to fire at a later date. Users can create schedules using cron expressions, and events can be persisted in a database.
This transport makes use of the Quartz Project at Open Symphony. The Quartz site has more generic information about how to work with Quartz.
About Cron Expressions
A cron expression is a string comprised by six or seven fields separated by white space. Fields can contain any of the allowed values, along with various combinations of the allowed special characters for that field. The fields are as follows:
Field Name
Mandatory
Allowed Values
Allowed Special Chars
Seconds
YES
0-59
, - * /
Minutes
YES
0-59
, - * /
Hours
YES
0-23
, - * /
Day of Month
YES
1-31
, - * ? / L W C
Month
YES
1-12 or JAN-DEC
, - * /
Day of Week
YES
1-7 or SUN-SAT
, - * ? / L C #
Year
NO
empty, 1970-2099
, - * /
Cron expressions can be as simple as this: * * * * ? *
or more complex, like this: 0 0/5 14,18,3-39,52 ? JAN,MAR,SEP MON-FRI 2002-2010.
Following are some examples:
Expression
Behavior
0 0 12 * * ?
Fire at 12pm (noon) every day
0 15 10 ? * *
Fire at 10:15am every day
0 15 10 * * ?
Fire at 10:15am every day
0 15 10 * * ? *
Fire at 10:15am every day
0 15 10 * * ? 2005
Fire at 10:15am every day during the year 2005
0 * 14 * * ?
Fire every minute starting at 2pm and ending at 2:59pm, every day
0 0/5 14 * * ?
Fire every 5 minutes starting at 2pm and ending at 2:55pm, every day
If you are not familiar with cron syntax, here is a good tutorial.
About Jobs
Jobs are used to perform an action when a time trigger occurs from the Quartz transport. Mule provides a number of jobs for generating and scheduling events. These are detailed below. Users can also write their own jobs and hook them in using the custom-job type included with Mule.
Connector The Quartz connector is used to configure the default behavior for Quartz endpoints that reference the connector. Note if there is only one Quartz connector configured, all Quartz endpoints will use that connector.
Attributes of <connector...>
Name
Type
Required
Default
Description
scheduler-ref
string
no
Provides an implementation of the Quartz Scheduler interface. If no value is provided, a scheduler is retrieved from the StdSchedulerFactory. If no properties are provided, the getDefaultScheduler method is called. Otherwise, a new factory instance is created using the given properties, and a scheduler is retrieved using the getScheduler method.
Child Elements of <connector...>
Name
Cardinality
Description
factory-property
0..*
Set a property on the factory (see scheduler-ref).
Outbound Endpoint An outbound Quartz endpoint allows existing events to be stored and fired at a later time/date. If you are using a persistent event store, the payload of the event must implement java.io.Serializable. You configure an org.quartz.Job implementation on the endpoint to tell it what action to take. Mule has some default jobs, but you can also write your own.
Attributes of <outbound-endpoint...>
Name
Type
Required
Default
Description
jobName
string
no
The name to associate with the job on the endpoint. This is only really used internally when storing events.
cronExpression
string
no
The cron expression to schedule events at specified dates/times. This attribute or repeatInterval is required.
repeatInterval
long
no
The number of milliseconds between two events. This attribute or cronExpression is required.
repeatCount
integer
no
The number of events to be scheduled. This value defaults to -1, which means that the events will be scheduled indefinitely.
startDelay
long
no
The number of milliseconds that will elapse before the first event is fired.
Child Elements of <outbound-endpoint...>
Name
Cardinality
Description
abstract-job
1..1
A placeholder for Quartz jobs that can be set on the endpoint.
Inbound Endpoint A Quartz inbound endpoint can be used to generate events. It is most useful when you want to trigger a service at a given interval (or cron expression) rather than have an external event trigger the service.
Attributes of <inbound-endpoint...>
Name
Type
Required
Default
Description
jobName
string
no
The name to associate with the job on the endpoint. This is only really used internally when storing events.
cronExpression
string
no
The cron expression to schedule events at specified dates/times. This attribute or repeatInterval is required.
repeatInterval
long
no
The number of milliseconds between two events. This attribute or cronExpression is required.
repeatCount
integer
no
The number of events to be scheduled. This value defaults to -1, which means that the events will be scheduled indefinitely.
startDelay
long
no
The number of milliseconds that will elapse before the first event is fired.
Child Elements of <inbound-endpoint...>
Name
Cardinality
Description
abstract-job
1..1
A placeholder for Quartz jobs that can be set on the endpoint.
Endpoint A global endpoint that can be used as a template to create inbound and outbound Quartz endpoints. Common configuration can be set on a global endpoint and then referenced using the @ref attribute on the local endpoint. Note that because jobs sometimes only work on inbound or outbound endpoints, they have to be set on the local endpoint.
Attributes of <endpoint...>
Name
Type
Required
Default
Description
jobName
string
no
The name to associate with the job on the endpoint. This is only really used internally when storing events.
cronExpression
string
no
The cron expression to schedule events at specified dates/times. This attribute or repeatInterval is required.
repeatInterval
long
no
The number of milliseconds between two events. This attribute or cronExpression is required.
repeatCount
integer
no
The number of events to be scheduled. This value defaults to -1, which means that the events will be scheduled indefinitely.
startDelay
long
no
The number of milliseconds that will elapse before the first event is fired.
Child Elements of <endpoint...>
Name
Cardinality
Description
abstract-job
0..1
A placeholder for Quartz jobs that can be set on the endpoint.
Abstract Job A placeholder for Quartz jobs that can be set on the endpoint.
Attributes of <abstract-job...>
Name
Type
Required
Default
Description
groupName
string
no
The group name of the scheduled job
jobGroupName
string
no
The job group name of the scheduled job.
Abstract Inbound Job A placeholder for Quartz jobs that can be set on inbound endpoints only.
Attributes of <abstract-inbound-job...>
Name
Type
Required
Default
Description
groupName
string
no
The group name of the scheduled job
jobGroupName
string
no
The job group name of the scheduled job.
Event Generator Job An inbound endpoint job that will trigger a new event for the service according to the schedule on the endpoint. This is useful for periodically triggering a service without the need for an external event to occur.
Child Elements of <event-generator-job...>
Name
Cardinality
Description
payload
0..1
The payload of the newly created event. The payload can be a reference to a file, fixed string, or object configured as a Spring bean. If this value is not set, an event will be generated with an org.mule.transport.NullPayload instance.
Following is an example:
Click here to expand...
<service name="testService1"><description>
This configuration will create an inbound event for testService1 at 12 noon every day. The event payload will always have the same value 'foo'.
</description><inbound><quartz:inbound-endpoint name="qEP1" cronExpression="0 0 12 * * ?" jobName="job1" connector-ref="quartzConnector1"><quartz:event-generator-job><quartz:payload>foo</quartz:payload></quartz:event-generator-job></quartz:inbound-endpoint></inbound></service><service name="testService2"><description>
This configuration will create an inbound event for testService2 every 1 second indefinitely. The event payload will always have the same value, which the contents of the file 'payload-data.txt'. The file can be on the classpath of on the local file system.
</description><inbound>
<quartz:inbound-endpoint name="qEP2" repeatCount="10" repeatInterval="1000" jobName="job2"
connector-ref="quartzConnector1">
<quartz:event-generator-job ><quartz:payload file="payload-data.txt"/></quartz:event-generator-job></quartz:inbound-endpoint></inbound></service>
Endpoint Polling Job An inbound endpoint job that can be used to periodically read from an external source (via another endpoint). This can be useful for triggering time-based events from sources that do not support polling or for simply controlling the rate in which events are received from the source.
Child Elements of <endpoint-polling-job...>
Name
Cardinality
Description
job-endpoint
0..1
A reference to another configured endpoint from which events will be received.
For example:
Click here to expand...
<service name="testService5"><description>
The endpoint polling Job will try and perform a 'request' on any Mule endpoint. If a result is received it will be handed off to this 'testService5' service for processing. The trigger will fire every 5 minutes starting at 2pm and ending at 2:55pm, every day. during this period the job will check the file directory /N/drop-data/in every 5 minutes to see if any event data is available. The request will timeout after 4 seconds if there are no files in the directory.
</description><inbound>
<quartz:inbound-endpoint name="qEP5" cronExpression="0 0/5 14 * * ?" jobName="job5"
connector-ref="quartzConnector1">
<quartz:endpoint-polling-job><quartz:job-endpoint address="file:///N/drop-data/in" timeout="4000"/></quartz:endpoint-polling-job></quartz:inbound-endpoint></inbound></service>
Scheduled Dispatch Job An outbound job that will schedule a job for dispatch at a later time/date. The event will get dispatched using the configured endpoint reference.
Child Elements of <scheduled-dispatch-job...>
Name
Cardinality
Description
job-endpoint
0..1
The endpoint used to dispatch the scheduled event. The preferred approach is to create a global endpoint and reference it using the ref attribute. However, you can also use the address attribute to define a URI endpoint (which supports expressions). You can use the timeout attribute to specify an arbitrary time-out value associated with the endpoint that can be used by jobs that block waiting to receive events.
For example:
Click here to expand...
<service name="testService6"><description>
This outbound Quartz endpoint will receive an event after the component has processed it and store it in the event store. When the trigger kicks in at 10:15am everyday it will dispatch the event on the endpoint referenced as 'scheduledDispatchEndpoint'. Since the 'repeatCount' is set to 0, the event will only be sent out once.
</description><inbound><inbound-endpoint address="test://inbound6"/></inbound><test:component/><outbound><pass-through-router>
<quartz:outbound-endpoint name="qEP6" repeatCount="0" cronExpression="0 15 10 * * ? *"
jobName="job6" connector-ref="quartzConnector1">
<quartz:scheduled-dispatch-job><quartz:job-endpoint ref="scheduledDispatchEndpoint"/></quartz:scheduled-dispatch-job></quartz:outbound-endpoint></pass-through-router></outbound></service>
Custom Job A custom job can be configured on inbound or outbound endpoints. You can create and configure your own job implementation and use it on a Quartz endpoint. A custom job can be configured as a bean in the XML configuration and referenced using this job.
Attributes of <custom-job...>
Name
Type
Required
Default
Description
groupName
string
no
The group name of the scheduled job
jobGroupName
string
no
The job group name of the scheduled job.
job-ref
string
no
The bean name or ID of the custom job to use when this job gets executed.
For example:
Click here to expand...
<service name="testService5"><description>
The endpoint polling Job will try and perform a 'request' on any Mule endpoint. If a result is received it will be handed off to this 'testService5' service for processing. The trigger will fire every 5 minutes starting at 2pm and ending at 2:55pm, every day. during this period the job will check the file directory /N/drop-data/in every 5 minutes to see if any event data is available. The request will timeout after 4 seconds if there are no files in the directory.
</description><inbound>
<quartz:inbound-endpoint name="qEP5" cronExpression="0 0/5 14 * * ?" jobName="job5"
connector-ref="quartzConnector1">
<quartz:endpoint-polling-job><quartz:job-endpoint address="file:///N/drop-data/in" timeout="4000"/></quartz:endpoint-polling-job></quartz:inbound-endpoint></inbound></service>
Custom Job From Message Allows a job to be stored on the current message. This can only be used on outbound endpoints. When the message is received, the job is read and the job is added to the scheduler with the current message. This allows for custom scheduling behavior determined by the message itself. Usually the service or a transformer would create the job on the message based on application-specific logic. Any Mule-supported expressions can be used to read the job from the message. Typically, you add the job as a header, but an attachment could also be used.
Attributes of <custom-job-from-message...>
Name
Type
Required
Default
Description
groupName
string
no
The group name of the scheduled job
jobGroupName
string
no
The job group name of the scheduled job.
For example:
Click here to expand...
<service name="testService3"><description>
This configuration will process a message and find a Job configured as a header called 'jobConfig' on the current message. We're using the test component here, but a real implementation will need to set a custom {{org.quartz.Job}} implementation as a header on the current message. Note that other expressions could be used to extract the job from an attachment or even a property within the payload itself.
</description><inbound><inbound-endpoint address="test://inbound3"/></inbound><test:component/><outbound><pass-through-router>
<quartz:outbound-endpoint name="qEP3" repeatInterval="1000" jobName="job3"
connector-ref="quartzConnector1">
<quartz:custom-job-from-message evaluator="header" expression="jobConfig"/></quartz:outbound-endpoint></pass-through-router></outbound></service>