简介

定义解析已知的缓存注解类型策的略接口；
AnnotationCacheOperationSource委托它们实现解析Spring的缓存注解：@Cacheable/@CachePut/@CacheEvict/@Caching；

核心代码

/*** 判断targetClass是否需要本parser解析缓存动作*/
default boolean isCandidateClass(Class<?> targetClass) {return true;
}/*** 解析指定类上的缓存注解*/
@Nullable
Collection<CacheOperation> parseCacheAnnotations(Class<?> type);/*** 解析指定方法上的缓存注解*/
@Nullable
Collection<CacheOperation> parseCacheAnnotations(Method method);

实现子类

public interface CacheAnnotationParserpublic class SpringCacheAnnotationParser implements CacheAnnotationParser, Serializable

SpringCacheAnnotationParser

简介

解析SpringCache的注解的策略实现；

核心代码

// 默认拥有SpringCache的注解：@Cacheable/@CachePut/@CacheEvict/@Caching
private static final Set<Class<? extends Annotation>> CACHE_OPERATION_ANNOTATIONS = new LinkedHashSet<>(8);
static {CACHE_OPERATION_ANNOTATIONS.add(Cacheable.class);CACHE_OPERATION_ANNOTATIONS.add(CacheEvict.class);CACHE_OPERATION_ANNOTATIONS.add(CachePut.class);CACHE_OPERATION_ANNOTATIONS.add(Caching.class);
}/*** 判断targetClass是否需要本parser解析缓存动作*/
public boolean isCandidateClass(Class<?> targetClass) {// targetClass的类/方法/属性上是否有SpringCache的任意一个注解return AnnotationUtils.isCandidateClass(targetClass, CACHE_OPERATION_ANNOTATIONS);
}/*** 解析指定类上的缓存注解*/
@Nullable
public Collection<CacheOperation> parseCacheAnnotations(Class<?> type) {// 获取类上的全局Cache配置，即@CacheConfig注解DefaultCacheConfig defaultConfig = new DefaultCacheConfig(type);return parseCacheAnnotations(defaultConfig, type);
}/*** 解析指定方法上的缓存注解*/
@Nullable
public Collection<CacheOperation> parseCacheAnnotations(Method method) {// 获取类上的全局Cache配置，即@CacheConfig注解DefaultCacheConfig defaultConfig = new DefaultCacheConfig(method.getDeclaringClass());return parseCacheAnnotations(defaultConfig, method);
}/*** 解析缓存注解*/
@Nullable
private Collection<CacheOperation> parseCacheAnnotations(DefaultCacheConfig cachingConfig, AnnotatedElement ae) {// 全面搜索整个类层次结构（包括超类和实现的接口）拥有的注解信息Collection<CacheOperation> ops = parseCacheAnnotations(cachingConfig, ae, false);if (ops != null && ops.size() > 1) {// 搜索直接声明的注解以及任何@Inherited超类拥有的注解信息// More than one operation found -> local declarations override interface-declared ones...Collection<CacheOperation> localOps = parseCacheAnnotations(cachingConfig, ae, true);if (localOps != null) {// 直接声明的注解信息优先于类层次结构声明的注解信息return localOps;}}return ops;
}/*** 解析缓存注解*/
@Nullable
private Collection<CacheOperation> parseCacheAnnotations(DefaultCacheConfig cachingConfig, AnnotatedElement ae, boolean localOnly) {// 搜索SpringCache注解信息Collection<? extends Annotation> anns = (localOnly ?AnnotatedElementUtils.getAllMergedAnnotations(ae, CACHE_OPERATION_ANNOTATIONS) :AnnotatedElementUtils.findAllMergedAnnotations(ae, CACHE_OPERATION_ANNOTATIONS));if (anns.isEmpty()) {// 未搜索到直接返回return null;}final Collection<CacheOperation> ops = new ArrayList<>(1);// 解析@Cacheable注解信息anns.stream().filter(ann -> ann instanceof Cacheable).forEach(ann -> ops.add(parseCacheableAnnotation(ae, cachingConfig, (Cacheable) ann)));// 解析@CacheEvict注解信息anns.stream().filter(ann -> ann instanceof CacheEvict).forEach(ann -> ops.add(parseEvictAnnotation(ae, cachingConfig, (CacheEvict) ann)));// 解析@CachePut注解信息anns.stream().filter(ann -> ann instanceof CachePut).forEach(ann -> ops.add(parsePutAnnotation(ae, cachingConfig, (CachePut) ann)));// 解析@Caching注解信息anns.stream().filter(ann -> ann instanceof Caching).forEach(ann -> parseCachingAnnotation(ae, cachingConfig, (Caching) ann, ops));return ops;
}/*** 解析@Cacheable注解*/
private CacheableOperation parseCacheableAnnotation(AnnotatedElement ae, DefaultCacheConfig defaultConfig, Cacheable cacheable) {CacheableOperation.Builder builder = new CacheableOperation.Builder();// 根据@Cacheable的属性设置CacheableOperation.Builderbuilder.setName(ae.toString());builder.setCacheNames(cacheable.cacheNames());builder.setCondition(cacheable.condition());builder.setUnless(cacheable.unless());builder.setKey(cacheable.key());builder.setKeyGenerator(cacheable.keyGenerator());builder.setCacheManager(cacheable.cacheManager());builder.setCacheResolver(cacheable.cacheResolver());builder.setSync(cacheable.sync());// 结合类的全局Cache配置得到最终CacheableOperation.BuilderdefaultConfig.applyDefault(builder);// 根据CacheableOperation.Builder生成CacheOperationCacheableOperation op = builder.build();// 校验CacheOperationvalidateCacheOperation(ae, op);return op;
}/*** 解析@Cacheable注解*/
private CacheEvictOperation parseEvictAnnotation(AnnotatedElement ae, DefaultCacheConfig defaultConfig, CacheEvict cacheEvict) {CacheEvictOperation.Builder builder = new CacheEvictOperation.Builder();// 根据@CacheEvict的属性设置CacheEvictOperation.Builderbuilder.setName(ae.toString());builder.setCacheNames(cacheEvict.cacheNames());builder.setCondition(cacheEvict.condition());builder.setKey(cacheEvict.key());builder.setKeyGenerator(cacheEvict.keyGenerator());builder.setCacheManager(cacheEvict.cacheManager());builder.setCacheResolver(cacheEvict.cacheResolver());builder.setCacheWide(cacheEvict.allEntries());builder.setBeforeInvocation(cacheEvict.beforeInvocation());// 结合类的全局Cache配置得到最终CacheEvictOperation.BuilderdefaultConfig.applyDefault(builder);// 根据CacheEvictOperation.Builder生成CacheOperationCacheEvictOperation op = builder.build();// 校验CacheOperationvalidateCacheOperation(ae, op);return op;
}/*** 解析@Cacheable注解*/
private CacheOperation parsePutAnnotation(AnnotatedElement ae, DefaultCacheConfig defaultConfig, CachePut cachePut) {CachePutOperation.Builder builder = new CachePutOperation.Builder();// 根据@CachePut的属性设置CachePutOperation.Builderbuilder.setName(ae.toString());builder.setCacheNames(cachePut.cacheNames());builder.setCondition(cachePut.condition());builder.setUnless(cachePut.unless());builder.setKey(cachePut.key());builder.setKeyGenerator(cachePut.keyGenerator());builder.setCacheManager(cachePut.cacheManager());builder.setCacheResolver(cachePut.cacheResolver());// 结合类的全局Cache配置得到最终CachePutOperation.BuilderdefaultConfig.applyDefault(builder);// 根据CachePutOperation.Builder生成CacheOperationCachePutOperation op = builder.build();// 校验CacheOperationvalidateCacheOperation(ae, op);return op;
}/*** 解析@Cacheable注解* @Caching就是@Cacheable/@CacheEvict/@CachePut的集合*/
private void parseCachingAnnotation(AnnotatedElement ae, DefaultCacheConfig defaultConfig, Caching caching, Collection<CacheOperation> ops) {// 解析包含的@CacheableCacheable[] cacheables = caching.cacheable();for (Cacheable cacheable : cacheables) {ops.add(parseCacheableAnnotation(ae, defaultConfig, cacheable));}// 解析包含的@CacheEvictCacheEvict[] cacheEvicts = caching.evict();for (CacheEvict cacheEvict : cacheEvicts) {ops.add(parseEvictAnnotation(ae, defaultConfig, cacheEvict));}// 解析包含的@CachePutCachePut[] cachePuts = caching.put();for (CachePut cachePut : cachePuts) {ops.add(parsePutAnnotation(ae, defaultConfig, cachePut));}
}/*** 校验CacheOperation*/
private void validateCacheOperation(AnnotatedElement ae, CacheOperation operation) {// key和keyGenerator二者存其一if (StringUtils.hasText(operation.getKey()) && StringUtils.hasText(operation.getKeyGenerator())) {throw new IllegalStateException("Invalid cache annotation configuration on '" +ae.toString() + "'. Both 'key' and 'keyGenerator' attributes have been set. " +"These attributes are mutually exclusive: either set the SpEL expression used to" +"compute the key at runtime or set the name of the KeyGenerator bean to use.");}// cacheManager和cacheResolver二者存其一if (StringUtils.hasText(operation.getCacheManager()) && StringUtils.hasText(operation.getCacheResolver())) {throw new IllegalStateException("Invalid cache annotation configuration on '" +ae.toString() + "'. Both 'cacheManager' and 'cacheResolver' attributes have been set. " +"These attributes are mutually exclusive: the cache manager is used to configure a" +"default cache resolver if none is set. If a cache resolver is set, the cache manager" +"won't be used.");}
}/*** 静态内部类，定义CacheOperation的默认缓存配置* 配置来源于类上的@CacheConfig注解*/
private static class DefaultCacheConfig {// 目标类private final Class<?> target;// 缓存标识符private String[] cacheNames;// KEY生成器private String keyGenerator;// 缓存管理器private String cacheManager;// 缓存解析器private String cacheResolver;// 初始化标识private boolean initialized = false;/*** 根据builder生成cache operation配置*/public void applyDefault(CacheOperation.Builder builder) {// 还未解析过target类的@CacheConfig（全局Cache配置），需要先获取类的全局Cache配置if (!this.initialized) {// 获取类上的@CacheConfig注解CacheConfig annotation = AnnotatedElementUtils.findMergedAnnotation(this.target, CacheConfig.class);if (annotation != null) {// 不存在，则使用@CacheConfig的配置作为默认配置，方法（或者属性）若有Cache配置则使用方法或者属性上的配置this.cacheNames = annotation.cacheNames();this.keyGenerator = annotation.keyGenerator();this.cacheManager = annotation.cacheManager();this.cacheResolver = annotation.cacheResolver();}// target类已经解析过全局Cache配置，无需再次解析this.initialized = true;}// 如果方法未配置缓存标识符，则使用类上的配置if (builder.getCacheNames().isEmpty() && this.cacheNames != null) {builder.setCacheNames(this.cacheNames);}// 如果方法未配置KEY/KEY生成器，则使用类上的配置if (!StringUtils.hasText(builder.getKey()) && !StringUtils.hasText(builder.getKeyGenerator()) &&StringUtils.hasText(this.keyGenerator)) {builder.setKeyGenerator(this.keyGenerator);}// 如果方法配置了缓存管理器或者缓存解析器，则无需类上的配置if (StringUtils.hasText(builder.getCacheManager()) || StringUtils.hasText(builder.getCacheResolver())) {// One of these is set so we should not inherit anything}// 使用类上的缓存解析器else if (StringUtils.hasText(this.cacheResolver)) {builder.setCacheResolver(this.cacheResolver);}// 使用类上的缓存管理器else if (StringUtils.hasText(this.cacheManager)) {builder.setCacheManager(this.cacheManager);}}
}