apache shiro叢集實現（二）— cache共用

    上一篇已經解決了第一個問題，session的共用，現在我們解決第二個問題cache的共用。

    先看下spring的設定檔，上一篇已經提到過了

<bean id="securityManager" class="org.apache.shiro.web.mgt.DefaultWebSecurityManager" depends-on="userRepository,roleRepository"><property name="sessionManager" ref="defaultWebSessionManager" /><property name="realm" ref="shiroDbRealm" /><property name="cacheManager" ref="memoryConstrainedCacheManager" /></bean><bean id="memoryConstrainedCacheManager" class="org.apache.shiro.cache.MemoryConstrainedCacheManager" />

    這裡cacheManager我們注入了shiro自定的本機記憶體實現的cacheManager類，當然，這肯定不滿足我們叢集的需要，所以我們要自己實現cacheManager類，這裡我還是用了redis作為cache的儲存，先建立CustomShiroCacheManager實作類別

public class CustomShiroCacheManager implements CacheManager, Destroyable {private ShiroCacheManager shiroCacheManager;public ShiroCacheManager getShiroCacheManager() {return shiroCacheManager;}public void setShiroCacheManager(ShiroCacheManager shiroCacheManager) {this.shiroCacheManager = shiroCacheManager;}@Overridepublic <K, V> Cache<K, V> getCache(String name) throws CacheException {return getShiroCacheManager().getCache(name);}@Overridepublic void destroy() throws Exception {shiroCacheManager.destroy();}}

這裡為了擴充，引入了ShiroCacheManager介面

public interface ShiroCacheManager {<K, V> Cache<K, V> getCache(String name);void destroy();}

下面我們自己實現redis的cacheManger

public class JedisShiroCacheManager implements ShiroCacheManager {@Autowiredprivate JedisCacheManager jedisCacheManager;@Overridepublic <K, V> Cache<K, V> getCache(String name) {return new JedisShiroCache<K, V>(name, jedisCacheManager);}@Overridepublic void destroy() {jedisCacheManager.getJedis().shutdown();}}

當然，這裡僅僅是getCache，我第一次看源碼時，也有這樣的疑問，cache的add、remove等等方法在哪裡實現呢。我們繼續看看shiro的源碼就會知道答案了

這個是自己relm的AuthorizingRealm中的方法

protected AuthorizationInfo getAuthorizationInfo(PrincipalCollection principals) {        if (principals == null) {            return null;        }        AuthorizationInfo info = null;        if (log.isTraceEnabled()) {            log.trace("Retrieving AuthorizationInfo for principals [" + principals + "]");        }        Cache<Object, AuthorizationInfo> cache = getAvailableAuthorizationCache();        if (cache != null) {            if (log.isTraceEnabled()) {                log.trace("Attempting to retrieve the AuthorizationInfo from cache.");            }            Object key = getAuthorizationCacheKey(principals);            info = cache.get(key);            if (log.isTraceEnabled()) {                if (info == null) {                    log.trace("No AuthorizationInfo found in cache for principals [" + principals + "]");                } else {                    log.trace("AuthorizationInfo found in cache for principals [" + principals + "]");                }            }        }        if (info == null) {            // Call template method if the info was not found in a cache            info = <strong>doGetAuthorizationInfo</strong>(principals);            // If the info is not null and the cache has been created, then cache the authorization info.            if (info != null && cache != null) {                if (log.isTraceEnabled()) {                    log.trace("Caching authorization info for principals: [" + principals + "].");                }                Object key = getAuthorizationCacheKey(principals);                <strong>cache.put</strong>(key, info);            }        }        return info;    }

如果大家去查查引入就知道我們自訂relm要實現一個叫做doGetAuthorizationInfo()的方法，它的作用是查詢授權資訊，我們注意加粗的2行，發現其實cache的put方法其實才是cache儲存的核心類，其實現都在cache中，所以我們需要實現自己的cache，建立JedisShiroCache類

public class JedisShiroCache<K, V> implements Cache<K, V> {private final String REDIS_SHIRO_CACHE = "shiro-cache:";private JedisManager jedisManager;private String name;public JedisShiroCache(String name, JedisManager jedisManager) {this.name = name;this.jedisManager = jedisManager;}/** * 自訂relm中的授權/認證的類名加上授權/認證英文名字 * @return */public String getName() {if (name == null)return "";return name;}public void setName(String name) {this.name = name;}@Overridepublic V get(K key) throws CacheException {byte[] byteKey = SerializeUtil.serialize(getCacheKey(key));byte[] byteValue = jedisManager.getValueByKey(byteKey);return (V) SerializeUtil.deserialize(byteValue);}@Overridepublic V put(K key, V value) throws CacheException {V previos = get(key);jedisManager.saveValueByKey(SerializeUtil.serialize(getCacheKey(key)),SerializeUtil.serialize(value));return previos;}@Overridepublic V remove(K key) throws CacheException {V previos = get(key);jedisManager.deleteByKey(SerializeUtil.serialize(getCacheKey(key)));return previos;}@Overridepublic void clear() throws CacheException {byte[] keysPattern = SerializeUtil.serialize(this.REDIS_SHIRO_CACHE+ "*");jedisManager.deleteByKeysPattern(keysPattern);}@Overridepublic int size() {if (keys() == null)return 0;return keys().size();}@Overridepublic Set<K> keys() {Set<byte[]> byteSet = jedisManager.getKeysByKeysPattern(SerializeUtil.serialize(this.REDIS_SHIRO_CACHE + "*"));Set<K> keys = new HashSet<K>();for (byte[] bs : byteSet) {keys.add((K) SerializeUtil.deserialize(bs));}return keys;}@Overridepublic Collection<V> values() {Set<byte[]> byteSet = jedisManager.getKeysByKeysPattern(SerializeUtil.serialize(this.REDIS_SHIRO_CACHE + "*"));List<V> result = new LinkedList<V>();for (byte[] bs : byteSet) {result.add((V) SerializeUtil.deserialize(jedisManager.getValueByKey(bs)));}return result;}private String getCacheKey(Object key) {return this.REDIS_SHIRO_CACHE + getName() + ":" + key;}

最後修改spring設定檔

<bean id="securityManager" class="org.apache.shiro.web.mgt.DefaultWebSecurityManager" depends-on="userRepository,roleRepository"> <property name="sessionManager" ref="defaultWebSessionManager" /><property name="realm" ref="shiroDbRealm" /><property name="cacheManager" ref="customShiroCacheManager" /></bean><bean id="customShiroCacheManager" class="com.nfschina.fourjoy.security.shiro.custom.cache.CustomShiroCacheManager"><property name="shiroCacheManager" ref="jedisShiroCacheManager" /></bean><bean id="jedisShiroCacheManager" class="com.nfschina.fourjoy.security.shiro.custom.cache.JedisShiroCacheManager" />

這樣就完成了整個shiro叢集的配置

源碼地址：https://github.com/michaelliuyang/shiro-redis-cluster