ehcache 3 not working with Sprint Boot 1.5.22

Question

I'm new to Java and SpringBoot.

ehcache.xml file in resources:

<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xmlns="http://www.ehcache.org/v3"
        xmlns:jsr107="http://www.ehcache.org/v3/jsr107"
        xsi:schemaLocation="
            http://www.ehcache.org/v3 http://www.ehcache.org/schema/ehcache-core-3.0.xsd
            http://www.ehcache.org/v3/jsr107 http://www.ehcache.org/schema/ehcache-107-ext-3.0.xsd">

    <cache alias="configCache">
        <key-type>java.lang.Integer</key-type>
        <value-type>java.lang.Integer</value-type>
        <expiry>
            <ttl unit="minutes">60</ttl>
        </expiry>

        <listeners>
            <listener>
                <class>com.demo.example.ehcache.CacheEventLogger</class>
                <event-firing-mode>ASYNCHRONOUS</event-firing-mode>
                <event-ordering-mode>UNORDERED</event-ordering-mode>
                <events-to-fire-on>CREATED</events-to-fire-on>
                <events-to-fire-on>EXPIRED</events-to-fire-on>
            </listener>
        </listeners>

        <resources>
            <heap unit="entries">2</heap>
            <offheap unit="MB">10</offheap>
        </resources>
    </cache>

</config>

The following line in application.properties:

spring.cache.jcache.config=classpath:ehcache.xml

CacheEventLogger:

package com.demo.example.ehcache;

import com.github.structlog4j.ILogger;
import com.github.structlog4j.SLoggerFactory;
import org.ehcache.event.CacheEvent;
import org.ehcache.event.CacheEventListener;

public class CacheEventLogger implements CacheEventListener<Object, Object> {
    private final ILogger log = SLoggerFactory.getLogger(CacheEventLogger.class);

    @Override
    public void onEvent(CacheEvent<? extends Object, ? extends Object> cacheEvent) {
        log.info("Cache event {} for item with key {}. Old value = {}, New value = {}",
                cacheEvent.getType(),
                cacheEvent.getKey(),
                cacheEvent.getOldValue(),
                cacheEvent.getNewValue());
    }
}

ConfigManager.Java:

package com.demo.example.ehcache;

import org.springframework.cache.annotation.Cacheable;

public class ConfigManager {
    public ConfigManager() {
    }

    @Cacheable(value = "configCache", key="#number")
    public int getNumber(int number) {
        return number;
    }
}

CachingConfig.java:

package com.demo.example.configuration;

import org.springframework.cache.annotation.EnableCaching;
import org.springframework.context.annotation.Configuration;


@Configuration
@EnableCaching
public class CachingConfig {

}

following dependencies in pom.xml:

    <dependency>
        <groupId>org.ehcache</groupId>
        <artifactId>ehcache</artifactId>
        <version>3.8.1</version>
    </dependency>
    <dependency>
        <groupId>javax.cache</groupId>
        <artifactId>cache-api</artifactId>
        <version>1.1.1</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-cache</artifactId>
    </dependency>

ServiceFacadeImpl.java:

@Component
public class ServiceFacadeImpl { 
  private final ConfigManager ConfigManager;

  ServiceFacadeImpl()
  {
    this.ConfigManager = new ConfigManager();
  }
 
  @Override
  public Integer getNumber() throws UpfrontException {
    configManager.getNumber(1); //hard coded 1 here
  }
}

I'm always passing a fixed Integer value of 1 in getNumber but it is always executing the function. Why isn't the cache working?

Answer 1

The problem was ConfigManager needs to be a @Component and should be injected into ServiceFacadeImpl.

ConfigManager:

package com.demo.example.ehcache;

import org.springframework.cache.annotation.Cacheable;

@Component
public class ConfigManager {
    public ConfigManager() {
    }

    @Cacheable(value = "configCache", key="#number")
    public int getNumber(int number) {
        return number;
    }
}

ServiceFacadeImpl:

@Component
public class ServiceFacadeImpl { 
  private final ConfigManager ConfigManager;

  ServiceFacadeImpl(ConfigManager configManager)
  {
    this.ConfigManager = configManager;
  }
 
  @Override
  public Integer getNumber() throws UpfrontException {
    configManager.getNumber(1); //hard coded 1 here
  }
}