Using @ConfigurationProperties in a @Scheduled annotation by referencing the bean name

Question

I'm using @ConfigurationProperties to configure the delay of a background task in Spring boot and I'm trying to use this value from a @Scheduled annotation on another component. However, in order to make it work I must use the full name given to the bean by Spring.

The configuration properties class is as follows:

@ConfigurationProperties("some")
class SomeProperties {
    private int millis; //the property is some.millis

    public int getMillis() {
        return millis;
    }

    public void setMillis(int millis) {
         this.millis = millis;
    }
}

And I'm using the value as follows in the scheduled method:

@Component
class BackgroundTasks {

    @Scheduled(fixedDelayString = "#{@'some-com.example.demo.SomeProperties'.millis}") //this works.
    public void sayHello(){
        System.out.println("hello");
    }
}

Is it possible to reference the value without having to use the full name of the bean? This answer suggests it is possible but I haven't been able to make it work.

Answer 1

Using @Componenton the properties class allows to access the property as "#{@someProperties.persistence.delay}.

More info in the spring boot documentation.

Answer 2

SomePrperties.java

package com.example.demo;

import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;

@ConfigurationProperties("some")
@Component("someProperties")
public class SomeProperties {

    private int millis; // the property is some.millis

    public int getMillis() {
        return millis;
    }

    public void setMillis(int millis) {
        this.millis = millis;
    }

}

BackgroundTasks.java

package com.example.demo;

import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;

@Component
public class BackgroundTasks {

    /**
     * 
     * Approach1: We can inject/access the property some.millis directly in @Value
     * fashion even though we have configured it to bind with SomeProperties class
     * using @ConfigurationProperties.
     * 
     * 
     */
    @Scheduled(fixedRateString = "${some.millis}")
    public void fromDirectInjection() {

        System.out.println("Hi, I'm  from DirectInjection method");

    }

    /**
     * 
     * Approach2: Add @Component on SomeProperties and access the bean bean's
     * property millis like below using Spring Expression language
     * 
     * 
     */
    @Scheduled(fixedRateString = "#{@someProperties.millis}")
    public void fromConfigurationProperty() {
        System.out.println("Hi, I'm from ConfigurationProperty method");

    }

}

DemoApplication.java

package com.example.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.scheduling.annotation.EnableScheduling;

@SpringBootApplication
@EnableScheduling
public class DemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }

}

application.properties

some.millis=2000

Version Used

 SpringBoot 2.6.0

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.6.0-SNAPSHOT</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demo</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>11</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
    <repositories>
        <repository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/milestone</url>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </repository>
        <repository>
            <id>spring-snapshots</id>
            <name>Spring Snapshots</name>
            <url>https://repo.spring.io/snapshot</url>
            <releases>
                <enabled>false</enabled>
            </releases>
        </repository>
    </repositories>
    <pluginRepositories>
        <pluginRepository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/milestone</url>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </pluginRepository>
        <pluginRepository>
            <id>spring-snapshots</id>
            <name>Spring Snapshots</name>
            <url>https://repo.spring.io/snapshot</url>
            <releases>
                <enabled>false</enabled>
            </releases>
        </pluginRepository>
    </pluginRepositories>

</project>

Output:

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::       (v2.6.0-SNAPSHOT)

2021-10-08 08:38:03.342  INFO 8092 --- [           main] com.example.demo.DemoApplication         : Starting DemoApplication using Java 14.0.2 on TO-GZ9M403-L with PID 8092 (D:\workspaces\configprop\demo (1)\demo\target\classes started by D1 in D:\workspaces\configprop\demo (1)\demo)
2021-10-08 08:38:03.345  INFO 8092 --- [           main] com.example.demo.DemoApplication         : No active profile set, falling back to default profiles: default
2021-10-08 08:38:04.884  INFO 8092 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8080 (http)
2021-10-08 08:38:04.902  INFO 8092 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
2021-10-08 08:38:04.902  INFO 8092 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.53]
2021-10-08 08:38:05.050  INFO 8092 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2021-10-08 08:38:05.050  INFO 8092 --- [           main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 1631 ms
2021-10-08 08:38:05.644  INFO 8092 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''
Hi, I'm  from DirectInjection method
Hi, I'm from ConfigurationProperty method
2021-10-08 08:38:05.662  INFO 8092 --- [           main] com.example.demo.DemoApplication         : Started DemoApplication in 2.995 seconds (JVM running for 3.712)
Hi, I'm  from DirectInjection method
Hi, I'm from ConfigurationProperty method
Hi, I'm  from DirectInjection method
Hi, I'm from ConfigurationProperty method
Hi, I'm  from DirectInjection method
Hi, I'm from ConfigurationProperty method