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转载请注明出处哈:http://carlosfu.iteye.com/blog/2237511
- 一、Ehcache三个重要的类
1. CacheManager: 管理Cache
2. Cache: 管理K-V缓存对象
3. Element: K-V缓存对象
下面这张图形象表现三者的关系:
二、Ehcache常用API
1. 创建CacheManager有多种方法:
CacheManager.newInstance(Configuration configuration) – Create a new CacheManager or return the existing one named in the configuration.(非单例) CacheManager.create() – Create a new singleton CacheManager with default configuration, or return the existing singleton. This is the same as CacheManager.getInstance().(单例) CacheManager.create(Configuration configuration) – Create a singleton CacheManager with the passed-in configuration, or return the existing singleton.(单例) new CacheManager(Configuration configuration) – Create a new CacheManager, or throw an exception if the CacheManager named in the configuration already exists or if the parameter (configuration) is null.(非单例)
实际应用建议使用第三种:CacheManager.create(Configuration configuration)
CacheManager cacheManager = CacheManager.create(BaseTest.class.getClassLoader().getResourceAsStream("ehcache.xml")); //加入jmx MBeanServer mBeanServer = ManagementFactory.getPlatformMBeanServer(); ManagementService.registerMBeans(cacheManager, mBeanServer, true, true, true, true); Cache cache = cacheManager.getCache("yourCacheName");
2. Cache常用API
(1) 添加和更新key-value
//add cache.put(new Element("key1", "value1")); //This updates the entry for "key1" cache.put(new Element("key1", "value2"));
(2) 获取key-value:
The following gets a Serializable value from an element with a key of key1. Cache cache = manager.getCache("sampleCache1"); Element element = cache.get("key1"); Serializable value = element.getValue(); The following gets a NonSerializable value from an element with a key of key1. Cache cache = manager.getCache("sampleCache1"); Element element = cache.get("key1"); Object value = element.getObjectValue();
(3) 删除key-value:
cache.remove("key1");
(4)获取cache大小:
The following gets the number of elements currently in the cache. int elementsInMemory = cache.getSize(); The following gets the number of elements currently in the MemoryStore. long elementsInMemory = cache.getMemoryStoreSize(); The following gets the number of elements currently in the DiskStore. long elementsOnDisk = cache.getDiskStoreSize();
(5)获取内存使用情况(生产环境不用使用,影响性能):
cache.calculateInMemorySize()
(6) 判断key是否过期:
boolean isExpired = cache.isExpired(Element element)
(7) 获取统计信息:
StatisticsGateway statisticsGateway = ehcache.getStatistics();
(8) 批量添加:
void putAll(Collection<Element> elements)
(9) 批量获取:
Map<Object,Element> getAll(Collection<?> keys)
(10) 判断key的位置:
boolean isElementInMemory(Object key) boolean isElementOnDisk(Object key)