Spring Cache @Cacheable-从同一个bean的另一个方法调用时不起作用

从同一bean的另一个方法调用缓存的方法时，Spring缓存不起作用。

这是一个清楚地说明我的问题的示例。

组态：

<cache:annotation-driven cache-manager="myCacheManager" />

<bean id="myCacheManager" class="org.springframework.cache.ehcache.EhCacheCacheManager">
    <property name="cacheManager" ref="myCache" />
</bean>

<!-- Ehcache library setup -->
<bean id="myCache"
    class="org.springframework.cache.ehcache.EhCacheManagerFactoryBean" p:shared="true">
    <property name="configLocation" value="classpath:ehcache.xml"></property>
</bean>

<cache name="employeeData" maxElementsInMemory="100"/>  

缓存的服务：

@Named("aService")
public class AService {

    @Cacheable("employeeData")
    public List<EmployeeData> getEmployeeData(Date date){
    ..println("Cache is not being used");
    ...
    }

    public List<EmployeeEnrichedData> getEmployeeEnrichedData(Date date){
        List<EmployeeData> employeeData = getEmployeeData(date);
        ...
    }

}

结果：

aService.getEmployeeData(someDate);
output: Cache is not being used
aService.getEmployeeData(someDate); 
output: 
aService.getEmployeeEnrichedData(someDate); 
output: Cache is not being used

该getEmployeeData方法调用使用缓存employeeData在第二次调用预期。但是，getEmployeeData在AService类中（getEmployeeEnrichedData）中调用该方法时，则未使用Cache。

这是Spring缓存的工作方式还是我缺少什么？

我相信这是这样的。从我记得阅读的内容来看，生成了一个代理类，该代理类可以拦截所有请求并使用缓存的值进行响应，但是同一类内的“内部”调用将无法获取缓存的值。

来自https://code.google.com/p/ehcache-spring-annotations/wiki/UsingCacheable

仅拦截通过代理传入的外部方法调用。这意味着自调用实际上是目标对象中的一种方法，它调用目标对象的另一种方法，即使调用的方法标记有@Cacheable，也不会在运行时导致实际的缓存拦截。

从Spring 4.3开始，可以通过在标注上使用自动装配来解决此问题@Resource：

@Component
@CacheConfig(cacheNames = "SphereClientFactoryCache")
public class CacheableSphereClientFactoryImpl implements SphereClientFactory {

    /**
     * 1. Self-autowired reference to proxified bean of this class.
     */
    @Resource
    private SphereClientFactory self;

    @Override
    @Cacheable(sync = true)
    public SphereClient createSphereClient(@Nonnull TenantConfig tenantConfig) {
        // 2. call cached method using self-bean
        return self.createSphereClient(tenantConfig.getSphereClientConfig());
    }

    @Override
    @Cacheable(sync = true)
    public SphereClient createSphereClient(@Nonnull SphereClientConfig clientConfig) {
        return CtpClientConfigurationUtils.createSphereClient(clientConfig);
    }
}

下面的示例是我用来从同一bean中打代理的示例，它类似于@ mario-eis的解决方案，但我发现它更具可读性（也许不是：-）。无论如何，我喜欢在服务级别上保留@Cacheable批注：

@Service
@Transactional(readOnly=true)
public class SettingServiceImpl implements SettingService {

@Inject
private SettingRepository settingRepository;

@Inject
private ApplicationContext applicationContext;

@Override
@Cacheable("settingsCache")
public String findValue(String name) {
    Setting setting = settingRepository.findOne(name);
    if(setting == null){
        return null;
    }
    return setting.getValue();
}

@Override
public Boolean findBoolean(String name) {
    String value = getSpringProxy().findValue(name);
    if (value == null) {
        return null;
    }
    return Boolean.valueOf(value);
}

/**
 * Use proxy to hit cache 
 */
private SettingService getSpringProxy() {
    return applicationContext.getBean(SettingService.class);
}
...

另请参见在Spring bean中启动新事务

这是我对仅少量使用同一类中的方法调用的小型项目所做的工作。强烈建议使用编码中的文档，因为对同事来说，它可能看起来很有趣。但是它易于测试，简单，快速实现，并为我省去了成熟的AspectJ仪器。但是，对于更繁重的用法，我建议使用AspectJ解决方案。

@Service
@Scope(proxyMode = ScopedProxyMode.TARGET_CLASS)
class AService {

    private final AService _aService;

    @Autowired
    public AService(AService aService) {
        _aService = aService;
    }

    @Cacheable("employeeData")
    public List<EmployeeData> getEmployeeData(Date date){
        ..println("Cache is not being used");
        ...
    }

    public List<EmployeeEnrichedData> getEmployeeEnrichedData(Date date){
        List<EmployeeData> employeeData = _aService.getEmployeeData(date);
        ...
    }
}

在我的情况下，我添加变量：

@Autowired
private AService  aService;

所以我getEmployeeData通过使用aService

@Named("aService")
public class AService {

@Cacheable("employeeData")
public List<EmployeeData> getEmployeeData(Date date){
..println("Cache is not being used");
...
}

public List<EmployeeEnrichedData> getEmployeeEnrichedData(Date date){
    List<EmployeeData> employeeData = aService.getEmployeeData(date);
    ...
}

}

在这种情况下，它将使用缓存。

使用静态编织在您的bean周围创建代理。在这种情况下，即使“内部”方法也可以正常工作

FactoryInternalCache为此，我使用带有内部缓存的内部内部bean（）：

@Component
public class CacheableClientFactoryImpl implements ClientFactory {

private final FactoryInternalCache factoryInternalCache;

@Autowired
public CacheableClientFactoryImpl(@Nonnull FactoryInternalCache factoryInternalCache) {
    this.factoryInternalCache = factoryInternalCache;
}

/**
 * Returns cached client instance from cache.
 */
@Override
public Client createClient(@Nonnull AggregatedConfig aggregateConfig) {
    return factoryInternalCache.createClient(aggregateConfig.getClientConfig());
}

/**
 * Returns cached client instance from cache.
 */
@Override
public Client createClient(@Nonnull ClientConfig clientConfig) {
    return factoryInternalCache.createClient(clientConfig);
}

/**
 * Spring caching feature works over AOP proxies, thus internal calls to cached methods don't work. That's why
 * this internal bean is created: it "proxifies" overloaded {@code #createClient(...)} methods
 * to real AOP proxified cacheable bean method {@link #createClient}.
 *
 * @see <a href="/programming/16899604/spring-cache-cacheable-not-working-while-calling-from-another-method-of-the-s">Spring Cache @Cacheable - not working while calling from another method of the same bean</a>
 * @see <a href="/programming/12115996/spring-cache-cacheable-method-ignored-when-called-from-within-the-same-class">Spring cache @Cacheable method ignored when called from within the same class</a>
 */
@EnableCaching
@CacheConfig(cacheNames = "ClientFactoryCache")
static class FactoryInternalCache {

    @Cacheable(sync = true)
    public Client createClient(@Nonnull ClientConfig clientConfig) {
        return ClientCreationUtils.createClient(clientConfig);
    }
}
}

到目前为止，最简单的解决方案就是像这样引用：

AService.this.getEmployeeData(date);