在没有 XML 的 Spring 4 中使用 EhCache

Question

有没有办法在 Spring 4 或 Spring Boot 中不使用 xml 来初始化 EhCache？

我注意到 Spring Boot 1.0.0.RC3 没有任何 ehcache 依赖项，但 Spring 4.0GA release post 提到它改进了对 EhCache 的支持。此外，Spring 3 有 org.springframework.cache.ehcache.EhCacheCacheManager 类，但这不再是依赖项的一部分。

编辑： Spring 4 确实支持 EhCache。您必须添加依赖项：

<groupId>org.springframework</groupId>
<artifactId>spring-context-support</artifactId>

编辑2： 我尝试了以下方法，我想我已经接近了，但我收到了一个错误：

@Bean
@Override
public CacheManager cacheManager() {
    CacheConfiguration cacheConfiguration = new CacheConfiguration();
    cacheConfiguration.setName("primary");
    cacheConfiguration.setMemoryStoreEvictionPolicy("LRU");
    cacheConfiguration.setMaxEntriesLocalHeap(0);

    net.sf.ehcache.config.Configuration config = new net.sf.ehcache.config.Configuration();
    config.addCache(cacheConfiguration);

    net.sf.ehcache.CacheManager cacheManager = new net.sf.ehcache.CacheManager(config);
    cacheManager.setName("EhCache");

    return new EhCacheCacheManager(cacheManager);
}

@Bean
public EhCacheManagerFactoryBean factoryBean() {
    return new EhCacheManagerFactoryBean();
}

错误

Caused by: net.sf.ehcache.CacheException: Another unnamed CacheManager already exists in the same VM. Please provide unique names for each CacheManager in the config or do one of following:
1. Use one of the CacheManager.create() static factory methods to reuse same CacheManager with same name or create one if necessary
2. Shutdown the earlier cacheManager before creating new one with same name.
The source of the existing CacheManager is: [Programmatically configured]
    at net.sf.ehcache.CacheManager.assertNoCacheManagerExistsWithSameName(CacheManager.java:590)
    at net.sf.ehcache.CacheManager.init(CacheManager.java:384)
    at net.sf.ehcache.CacheManager.<init>(CacheManager.java:263)
    at org.springframework.cache.ehcache.EhCacheManagerFactoryBean.afterPropertiesSet(EhCacheManagerFactoryBean.java:166)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1612)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1549)
    ... 15 more

Answer 1

Spring 中 EhCache 的 XML-less 配置

@Configuration
@EnableCaching
public class CachingConfig implements CachingConfigurer {
    @Bean(destroyMethod="shutdown")
    public net.sf.ehcache.CacheManager ehCacheManager() {
        CacheConfiguration cacheConfiguration = new CacheConfiguration();
        cacheConfiguration.setName("myCacheName");
        cacheConfiguration.setMemoryStoreEvictionPolicy("LRU");
        cacheConfiguration.setMaxEntriesLocalHeap(1000);

        net.sf.ehcache.config.Configuration config = new net.sf.ehcache.config.Configuration();
        config.addCache(cacheConfiguration);

        return net.sf.ehcache.CacheManager.newInstance(config);
    }

    @Bean
    @Override
    public CacheManager cacheManager() {
        return new EhCacheCacheManager(ehCacheManager());
    }

    @Bean
    @Override
    public KeyGenerator keyGenerator() {
        return new SimpleKeyGenerator();
    }

    @Bean
    @Override
    public CacheResolver cacheResolver()    {
        return new SimpleCacheResolver();
    }

    @Bean
    @Override
    public CacheErrorHandler errorHandler() {
         return new SimpleCacheErrorHandler();
    }
}

或者，为了测试，您可以使用一个简单的 ConcurrentMapCache，如下所示，不使用 XML 运行。

@Configuration
@EnableCaching
public class CachingConfig implements CachingConfigurer {
    @Bean
    @Override
    public CacheManager cacheManager() {
        SimpleCacheManager cacheManager = new SimpleCacheManager();

        List<Cache> caches = new ArrayList<Cache>();
        caches.add(new ConcurrentMapCache("myCacheName"));
        cacheManager.setCaches(caches);

        return cacheManager;
    }

    @Bean
    @Override
    public KeyGenerator keyGenerator() {
        return new SimpleKeyGenerator();
    }

    @Bean
    @Override
    public CacheResolver cacheResolver()    {
        return new SimpleCacheResolver();
    }

    @Bean
    @Override
    public CacheErrorHandler errorHandler() {
         return new SimpleCacheErrorHandler();
    }
}

编辑：更新以在底层缓存上添加关闭方法

编辑：添加了错误处理程序和缓存解析器的配置

编辑：更改 SimpleCacheResolver 上的构造函数调用解决了 CacheManager must not be null 问题（Spring v5.1+）

@Configuration
@EnableCaching
public class CachingConfig implements CachingConfigurer {

    public static final String USER_CACHE_INSTANCE = "my-spring-ehcache";
    private final CacheManager cacheManager;
    private final net.sf.ehcache.CacheManager ehCacheManager;


    public CachingConfig() {
        CacheConfiguration cacheConfiguration = new CacheConfiguration();
        cacheConfiguration.setName(USER_CACHE_INSTANCE);
        cacheConfiguration.setMemoryStoreEvictionPolicy("LRU");
        cacheConfiguration.setMaxEntriesLocalHeap(1000);
        net.sf.ehcache.config.Configuration config
                = new net.sf.ehcache.config.Configuration();
        config.addCache(cacheConfiguration);
        this.ehCacheManager = net.sf.ehcache.CacheManager.newInstance(config);
        this.cacheManager = new EhCacheCacheManager(ehCacheManager);
    }

    @Bean(destroyMethod="shutdown")
    public net.sf.ehcache.CacheManager ehCacheManager() {
        return ehCacheManager;
    }

    @Bean
    @Override
    public CacheManager cacheManager() {
        return cacheManager;
    }

    @Bean
    @Override
    public KeyGenerator keyGenerator() {
        return new SimpleKeyGenerator();
    }

    @Bean
    @Override
    public CacheResolver cacheResolver() {
        return new SimpleCacheResolver(cacheManager);
    }

    @Bean
    @Override
    public CacheErrorHandler errorHandler() {
        return new SimpleCacheErrorHandler();
    }
}

Answer 2

我在两个抽象级别上执行此操作，每个技术（Ehcache、Redis 等）的配置文件和通用配置文件。

这是 Ehcache 的一个（Redis 类似）：

@Configuration
public class EhCacheConfiguration {

    @Bean
    public EhCacheCacheManager ehCacheCacheManager() {

        return new EhCacheCacheManager(ehCacheManagerFactoryBean().getObject());
    }


    @Bean
    public EhCacheManagerFactoryBean ehCacheManagerFactoryBean() {

        EhCacheManagerFactoryBean cacheManagerFactoryBean = new EhCacheManagerFactoryBean();

        cacheManagerFactoryBean.setConfigLocation(new ClassPathResource("ehcache.xml"));
        cacheManagerFactoryBean.setShared(true);

        return cacheManagerFactoryBean;
    }
}

这是一个通用的（包含 Redis 钩子）：

@Configuration
@EnableCaching
public class CachingConfiguration implements CachingConfigurer {

    @Qualifier("ehCacheCacheManager")
    @Autowired(required = false)
    private CacheManager ehCacheCacheManager;

    @Qualifier("redisCacheManager")
    @Autowired(required = false)
    private CacheManager redisCacheManager;


    @Bean
    @Override
    public CacheManager cacheManager() {

        List<CacheManager> cacheManagers = Lists.newArrayList();

        if (this.ehCacheCacheManager != null) {
            cacheManagers.add(this.ehCacheCacheManager);
        }

        if (this.redisCacheManager != null) {
            cacheManagers.add(this.redisCacheManager);
        }

        CompositeCacheManager cacheManager = new CompositeCacheManager();

        cacheManager.setCacheManagers(cacheManagers);
        cacheManager.setFallbackToNoOpCache(false);

        return cacheManager;
    }


    @Bean
    @Override
    public KeyGenerator keyGenerator() {

        return new DefaultKeyGenerator();
    }
}