PersistenceAnnotationBeanPostProcessor.java 文件源码

private InjectionMetadata findPersistenceMetadata(String beanName, final Class<?> clazz, PropertyValues pvs) {
    // Fall back to class name as cache key, for backwards compatibility with custom callers.
    String cacheKey = (StringUtils.hasLength(beanName) ? beanName : clazz.getName());
    // Quick check on the concurrent map first, with minimal locking.
    InjectionMetadata metadata = this.injectionMetadataCache.get(cacheKey);
    if (InjectionMetadata.needsRefresh(metadata, clazz)) {
        synchronized (this.injectionMetadataCache) {
            metadata = this.injectionMetadataCache.get(cacheKey);
            if (InjectionMetadata.needsRefresh(metadata, clazz)) {
                if (metadata != null) {
                    metadata.clear(pvs);
                }
                try {
                    metadata = buildPersistenceMetadata(clazz);
                    this.injectionMetadataCache.put(cacheKey, metadata);
                }
                catch (NoClassDefFoundError err) {
                    throw new IllegalStateException("Failed to introspect bean class [" + clazz.getName() +
                            "] for persistence metadata: could not find class that it depends on", err);
                }
            }
        }
    }
    return metadata;
}