Quarkus Extension for Spring Scheduling API
While users are encouraged to use regular Quarkus scheduler, Quarkus provides a compatibility layer for Spring Scheduled in the form of the spring-scheduled extension.
This guide explains how a Quarkus application can leverage the well known Spring Scheduled annotation to configure and schedule tasks.
Requisitos previos
To complete this guide, you need:
-
Roughly 15 minutes
-
An IDE
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JDK 17+ installed with
JAVA_HOMEconfigured appropriately -
Apache Maven 3.9.9
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Optionally the Quarkus CLI if you want to use it
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Optionally Mandrel or GraalVM installed and configured appropriately if you want to build a native executable (or Docker if you use a native container build)
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Some familiarity with the Spring Web extension
Solución
We recommend that you follow the instructions in the next sections and create the application step by step. However, you can go right to the completed example.
Clone el repositorio Git: git clone https://github.com/quarkusio/quarkus-quickstarts.git o descargue un archivo.
The solution is located in the spring-scheduled-quickstart directory.
Creación del proyecto Maven
En primer lugar, necesitamos un nuevo proyecto. Cree un nuevo proyecto con el siguiente comando:
For Windows users:
-
If using cmd, (don’t use backward slash
\and put everything on the same line) -
If using Powershell, wrap
-Dparameters in double quotes e.g."-DprojectArtifactId=spring-scheduler-quickstart"
This command generates a Maven project with the spring-scheduled extension.
If you already have your Quarkus project configured, you can add the spring-scheduled extension
to your project by running the following command in your project base directory:
quarkus extension add spring-scheduled./mvnw quarkus:add-extension -Dextensions='spring-scheduled'./gradlew addExtension --extensions='spring-scheduled'Esto añadirá lo siguiente a su archivo de construcción:
<dependency>
<groupId>io.quarkus</groupId>
<artifactId>quarkus-spring-scheduled</artifactId>
</dependency>implementation("io.quarkus:quarkus-spring-scheduled")Creating a scheduled job
In the org.acme.spring.scheduler package, create the CounterBean class, with the following content:
package org.acme.spring.scheduler;
import org.springframework.scheduling.annotation.Scheduled;
import java.util.concurrent.atomic.AtomicInteger;
import jakarta.enterprise.context.ApplicationScoped;
@ApplicationScoped (1)
public class CounterBean {
private AtomicInteger counter = new AtomicInteger();
public int get() { (2)
return counter.get();
}
@Scheduled(cron="*/5 * * * * ?") (3)
void cronJob() {
counter.incrementAndGet(); (4)
System.out.println("Cron expression hardcoded");
}
@Scheduled(cron = "{cron.expr}") (5)
void cronJobWithExpressionInConfig() {
counter.incrementAndGet();
System.out.println("Cron expression configured in application.properties");
}
@Scheduled(fixedRate = 1000) (6)
void jobAtFixedRate() {
counter.incrementAndGet();
System.out.println("Fixed Rate expression");
}
@Scheduled(fixedRateString = "${fixedRate.expr}") (7)
void jobAtFixedRateInConfig() {
counter.incrementAndGet();
System.out.println("Fixed Rate expression configured in application.properties");
}
}| 1 | Declare the bean in the application scope. Spring only detects @Scheduled annotations in beans. |
| 2 | The get() method allows retrieving the current value. |
| 3 | Use the Spring @Scheduled annotation with a cron-like expression to instruct Quarkus to schedule this method run. In this example we’re scheduling a task to be executed at 10:15am every day. |
| 4 | The code is pretty straightforward. Every day at 10:15am, the counter is incremented. |
| 5 | Define a job with a cron-like expression cron.expr which is configurable in application.properties. |
| 6 | Define a method to be executed at a fixed interval of time. The period is expressed in milliseconds. |
| 7 | Define a job to be executed at a fixed interval of time fixedRate.expr which is configurable in application.properties. |
Updating the application configuration file
Edit the application.properties file and add the cron.expr and the fixedRate.expr configuration:
# The syntax used by Spring for cron expressions is the same as which is used by regular Quarkus scheduler.
cron.expr=*/5 * * * * ?
fixedRate.expr=1000Creating the resource and the test
Create the CountResource class with the following content:
package org.acme.spring.scheduler;
import jakarta.inject.Inject;
import jakarta.ws.rs.GET;
import jakarta.ws.rs.Path;
import jakarta.ws.rs.Produces;
import jakarta.ws.rs.core.MediaType;
@Path("/count")
public class CountResource {
@Inject
CounterBean counter; (1)
@GET
@Produces(MediaType.TEXT_PLAIN)
public String hello() {
return "count: " + counter.get(); (2)
}
}| 1 | Inject the CounterBean |
| 2 | Send back the current counter value |
We also need to update the tests. Edit the CountResourceTest class to match:
package org.acme.spring.scheduler;
import static io.restassured.RestAssured.given;
import static org.hamcrest.CoreMatchers.containsString;
import org.junit.jupiter.api.Test;
import io.quarkus.test.junit.QuarkusTest;
@QuarkusTest
public class CountResourceTest {
@Test
public void testHelloEndpoint() {
given()
.when().get("/count")
.then()
.statusCode(200)
.body(containsString("count")); (1)
}
}| 1 | Ensure that the response contains count |
Empaquetar y ejecutar la aplicación
Ejecuta la aplicación con:
quarkus dev./mvnw quarkus:dev./gradlew --console=plain quarkusDevIn another terminal, run curl localhost:8080/count to check the counter value.
After a few seconds, re-run curl localhost:8080/count to verify the counter has been incremented.
Observe the console to verify that the following messages has been displayed:
- Cron expression hardcoded
- Cron expression configured in application.properties
- Fixed Rate expression
- Fixed Rate expression configured in application.properties
These messages indicate that the executions of methods annotated with @Scheduled have been triggered.
As usual, the application can be packaged using:
quarkus build./mvnw install./gradlew buildAnd executed using java -jar target/quarkus-app/quarkus-run.jar.
You can also generate the native executable with:
quarkus build --native./mvnw install -Dnative./gradlew build -Dquarkus.native.enabled=trueUsing Property Expressions
Quarkus supports the use of property expressions in the application.properties file so to externalize the configuration of the tasks you should store the properties in the application.properties file and use the
fixedRateString, initialDelayString params respectively.
Note that this configuration is a build time configuration, the property expression will be resolved at build time.
Unsupported Spring Scheduled functionalities
Quarkus currently only supports a subset of the functionalities that Spring @Scheduled provides with more features being planned.
Currently, the fixedDelay and fixedDelayString parameters are not supported, in other words, @Scheduled methods are always executed independently.
Important Technical Note
Please note that the Spring support in Quarkus does not start a Spring Application Context nor are any Spring infrastructure classes run.
Spring classes and annotations are only used for reading metadata and / or are used as user code method return types or parameter types.
What that means for end users, is that adding arbitrary Spring libraries will not have any effect. Moreover, Spring infrastructure
classes (like org.springframework.beans.factory.config.BeanPostProcessor for example) will not be executed.
Más guías de Spring
Quarkus tiene más características de compatibilidad con Spring. Consulte las siguientes guías para obtener más detalles:
