[[io.quartz]]
= Quartz Scheduler

Spring Boot offers several conveniences for working with the https://www.quartz-scheduler.org/[Quartz scheduler], including the `spring-boot-starter-quartz` "`Starter`".
If Quartz is available, a `Scheduler` is auto-configured (through the `SchedulerFactoryBean` abstraction).

Beans of the following types are automatically picked up and associated with the `Scheduler`:

* `JobDetail`: defines a particular Job.
  `JobDetail` instances can be built with the `JobBuilder` API.
* `Calendar`.
* `Trigger`: defines when a particular job is triggered.

By default, an in-memory `JobStore` is used.
However, it is possible to configure a JDBC-based store if a `DataSource` bean is available in your application and if the configprop:spring.quartz.job-store-type[] property is configured accordingly, as shown in the following example:

[configprops,yaml]
----
spring:
  quartz:
    job-store-type: "jdbc"
----

When the JDBC store is used, the schema can be initialized on startup, as shown in the following example:

[configprops,yaml]
----
spring:
  quartz:
    jdbc:
      initialize-schema: "always"
----

WARNING: By default, the database is detected and initialized by using the standard scripts provided with the Quartz library.
These scripts drop existing tables, deleting all triggers on every restart.
It is also possible to provide a custom script by setting the configprop:spring.quartz.jdbc.schema[] property.

To have Quartz use a `DataSource` other than the application's main `DataSource`, declare a `DataSource` bean, annotating its `@Bean` method with `@QuartzDataSource`.
Doing so ensures that the Quartz-specific `DataSource` is used by both the `SchedulerFactoryBean` and for schema initialization.
Similarly, to have Quartz use a `TransactionManager` other than the application's main `TransactionManager` declare a `TransactionManager` bean, annotating its `@Bean` method with `@QuartzTransactionManager`.

By default, jobs created by configuration will not overwrite already registered jobs that have been read from a persistent job store.
To enable overwriting existing job definitions set the configprop:spring.quartz.overwrite-existing-jobs[] property.

Quartz Scheduler configuration can be customized using `spring.quartz` properties and `SchedulerFactoryBeanCustomizer` beans, which allow programmatic `SchedulerFactoryBean` customization.
Advanced Quartz configuration properties can be customized using `spring.quartz.properties.*`.

NOTE: In particular, an `Executor` bean is not associated with the scheduler as Quartz offers a way to configure the scheduler through `spring.quartz.properties`.
If you need to customize the task executor, consider implementing `SchedulerFactoryBeanCustomizer`.

Jobs can define setters to inject data map properties.
Regular beans can also be injected in a similar manner, as shown in the following example:

include-code::MySampleJob[]
