如何在没有 xml 的情况下配置 Ehcache 3 + spring boot + java config？

Question

我使用Ehcache 2 + spring boot。这是我的配置：

@Bean
public CacheManager cacheManager() {
    return new EhCacheCacheManager(ehCacheCacheManager().getObject());
}

@Bean
public EhCacheManagerFactoryBean ehCacheCacheManager() {
    EhCacheManagerFactoryBean cmfb = new EhCacheManagerFactoryBean();
    cmfb.setConfigLocation(new ClassPathResource("ehcache.xml"));
    cmfb.setShared(true);
    return cmfb;
}

ehcache.xml - in resources.

现在我想使用 Ehcache 3 + spring boot 和 Java config 而不是 xml 但我还没有找到任何示例。我的问题：

1) 为什么几乎所有的例子都是基于xml的？这怎么能比 java config 更好？

2) 如何不使用 xml 在 spring boot 中使用 java config 配置 Ehcache 3 >?

Answer 1

这是用于创建 Ehcache 管理器 bean 的等效 java 配置。

ApplicationConfig.java

@Configuration
@EnableCaching
public class ApplicationConfig {

    @Bean
    public CacheManager ehCacheManager() {
        CachingProvider provider = Caching.getCachingProvider();
        CacheManager cacheManager = provider.getCacheManager();

        CacheConfigurationBuilder<String, String> configuration =
                CacheConfigurationBuilder.newCacheConfigurationBuilder(
                        String.class,
                        String.class,
                     ResourcePoolsBuilder
                             .newResourcePoolsBuilder().offheap(1, MemoryUnit.MB))
                .withExpiry(ExpiryPolicyBuilder.timeToLiveExpiration(Duration.ofSeconds(20)));

        javax.cache.configuration.Configuration<String, String> stringDoubleConfiguration = 
Eh107Configuration.fromEhcacheCacheConfiguration(configuration);

            cacheManager.createCache("users", stringDoubleConfiguration);
            return cacheManager;

    }

}

ServiceImpl.java

@Service
public class ServiceImpl {

    @Cacheable(cacheNames = {"users"})
    public String getThis(String id) {
        System.out.println("Method called............");
        return "Value "+ id;
    }
}

pom.xml

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

Answer 2

有很多例子。我个人是 Java 配置的粉丝。

以下是主要的官方示例：

• Basic programmatic configuration
• Full fledge Spring-Boot configuration（包括集群）
• Simpler configuration with Spring PetClinic

Answer 3

我更喜欢使用 JAVA 配置而不是 XML 配置。下面有两个代码示例，它们的逻辑相同，但风格不同。

XML 方法：

import org.springframework.cache.annotation.EnableCaching;
import org.springframework.cache.ehcache.EhCacheCacheManager;
import org.springframework.cache.ehcache.EhCacheManagerFactoryBean;
import org.springframework.cache.support.CompositeCacheManager;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.core.io.ClassPathResource;

import java.util.Collections;

@EnableCaching
@Configuration
public class CacheConfig {

    @Primary
    @Bean("cacheManager")
    public CompositeCacheManager cacheManager() {
        CompositeCacheManager compositeCacheManager = new CompositeCacheManager();
        compositeCacheManager.setFallbackToNoOpCache(true);
        compositeCacheManager.setCacheManagers(Collections.singleton(ehCacheManager()));
        return compositeCacheManager;
    }

    @Bean("ehCacheManager")
    public EhCacheCacheManager ehCacheManager() {
        EhCacheCacheManager ehCacheCacheManager = new EhCacheCacheManager();
        ehCacheCacheManager.setCacheManager(ehCacheManagerFactoryBean().getObject());
        return ehCacheCacheManager;
    }

    @Bean
    public EhCacheManagerFactoryBean ehCacheManagerFactoryBean() {
        EhCacheManagerFactoryBean ehCacheManagerFactoryBean = new EhCacheManagerFactoryBean();
        ehCacheManagerFactoryBean.setShared(true);
        ehCacheManagerFactoryBean.setConfigLocation(new ClassPathResource("ehcache.xml"));
        return ehCacheManagerFactoryBean;
    }

}

ehcache.xml

<ehcache name="custom_eh_cache">
    <diskStore path="java.io.tmpdir"/>
    <cache name="users"
           maxElementsInMemory="1000"
           eternal="false"
           timeToIdleSeconds="3600"
           timeToLiveSeconds="3600"
           memoryStoreEvictionPolicy="LRU"/>
    <cache name="roles"
           maxElementsInMemory="1000"
           eternal="false"
           timeToIdleSeconds="3600"
           timeToLiveSeconds="3600"
           memoryStoreEvictionPolicy="LRU"/>    
</ehcache>

---

JAVA方法：

import net.sf.ehcache.Cache;
import net.sf.ehcache.CacheManager;
import net.sf.ehcache.config.CacheConfiguration;
import net.sf.ehcache.config.DiskStoreConfiguration;
import net.sf.ehcache.store.MemoryStoreEvictionPolicy;
import org.springframework.cache.annotation.EnableCaching;
import org.springframework.cache.ehcache.EhCacheCacheManager;
import org.springframework.cache.support.CompositeCacheManager;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;

import java.util.Collections;

@EnableCaching
@Configuration
public class CacheConfig {

    @Primary
    @Bean("cacheManager")
    public CompositeCacheManager cacheManager() {
        CompositeCacheManager compositeCacheManager = new CompositeCacheManager();
        compositeCacheManager.setFallbackToNoOpCache(true);
        compositeCacheManager.setCacheManagers(Collections.singleton(ehCacheManager()));
        return compositeCacheManager;
    }

    @Bean("ehCacheManager")
    public EhCacheCacheManager ehCacheManager() {
        EhCacheCacheManager ehCacheCacheManager = new EhCacheCacheManager();
        ehCacheCacheManager.setCacheManager(getCustomCacheManager());
        return ehCacheCacheManager;
    }

    private CacheManager getCustomCacheManager() {
        CacheManager cacheManager = CacheManager.create(getEhCacheConfiguration());
        cacheManager.setName("custom_eh_cache");
        cacheManager.addCache(createCache("users"));
        cacheManager.addCache(createCache("roles"));
        return cacheManager;
    }

    private Cache createCache(String cacheName) {
        CacheConfiguration cacheConfig = new CacheConfiguration(cacheName, 1000)
                .memoryStoreEvictionPolicy(MemoryStoreEvictionPolicy.LRU)
                .eternal(false)
                .timeToLiveSeconds(3600)
                .timeToIdleSeconds(3600);
        return new Cache(cacheConfig);
    }

    private net.sf.ehcache.config.Configuration getEhCacheConfiguration() {
        net.sf.ehcache.config.Configuration configuration = new net.sf.ehcache.config.Configuration();
        DiskStoreConfiguration diskStoreConfiguration = new DiskStoreConfiguration();
        diskStoreConfiguration.setPath("java.io.tmpdir");
        configuration.addDiskStore(diskStoreConfiguration);
        return configuration;
    }

}