Apache shiro集群实现（七）分布式集群系统下---cache共享

布满荆棘的人生 2022-08-05 12:24 217阅读 0赞

[Apache shiro集群实现 （一） shiro入门介绍][Apache shiro_ _ shiro]

[Apache shiro集群实现 （二） shiro 的INI配置][Apache shiro_ _ shiro _INI]

[Apache shiro集群实现 （三）shiro身份认证（Shiro Authentication）][Apache shiro_ _shiro_Shiro Authentication]

[Apache shiro集群实现 （四）shiro授权（Authentication）--访问控制][Apache shiro_ _shiro_Authentication_--]

[Apache shiro集群实现 （五）分布式集群系统下的高可用session解决方案][Apache shiro_ _session]

[Apache shiro集群实现 （六）分布式集群系统下的高可用session解决方案---Session共享][Apache shiro_ _session_---Session]

[Apache shiro集群实现（七）分布式集群系统下---cache共享][Apache shiro_---cache]  
[Apache shiro集群实现 （八） web集群时session同步的3种方法][Apache shiro_ _ web_session_3]

上一篇已经解决了第一个问题，session的共享，现在我们解决第二个问题cache的共享。

先看下spring的配置文件，上一篇已经提到过了

这里cacheManager我们注入了shiro自定的本机内存实现的cacheManager类，当然，这肯定不满足我们集群的需要，所以我们要自己实现cacheManager类，这里我还是用了redis作为cache的存储，先创建RedisCacheManager实现类

package com.tgb.itoo.authority.cache;
 
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 
 import org.apache.shiro.cache.Cache;
 import org.apache.shiro.cache.CacheException;
 import org.apache.shiro.cache.CacheManager;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 public class RedisCacheManager implements CacheManager{
 
 	private static final Logger logger = LoggerFactory
 			.getLogger(RedisCacheManager.class);
 
 	// fast lookup by name map
 	private final ConcurrentMap<String, Cache> caches = new ConcurrentHashMap<String, Cache>();
 
 	private RedisManager redisManager;
 
 	/**
 	 * The Redis key prefix for caches 
 	 */
 	private String keyPrefix = "shiro_redis_cache:";
 	
 	/**
 	 * Returns the Redis session keys
 	 * prefix.
 	 * @return The prefix
 	 */
 	public String getKeyPrefix() {
 		return keyPrefix;
 	}
 
 	/**
 	 * Sets the Redis sessions key 
 	 * prefix.
 	 * @param keyPrefix The prefix
 	 */
 	public void setKeyPrefix(String keyPrefix) {
 		this.keyPrefix = keyPrefix;
 	}
 	
 	@Override
 	public <K, V> Cache<K, V> getCache(String name) throws CacheException {
 		logger.debug("获取名称为: " + name + " 的RedisCache实例");
 		
 		Cache c = caches.get(name);
 		
 		if (c == null) {
 
 			// initialize the Redis manager instance
 			redisManager.init();
 			
 			// create a new cache instance
 			c = new RedisCache<K, V>(redisManager, keyPrefix);
 			
 			// add it to the cache collection
 			caches.put(name, c);
 		}
 		return c;
 	}
 
 	public RedisManager getRedisManager() {
 		return redisManager;
 	}
 
 	public void setRedisManager(RedisManager redisManager) {
 		this.redisManager = redisManager;
 	}
 }

当然，这里仅仅是getCache，我第一次看源码时，也有这样的疑问，cache的add、remove等等方法在哪里实现呢？我们继续看看shiro的源码就会知道答案了

这个是自己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 = doGetAuthorizationInfo(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); 
 cache.put(key, info); 
 } 
 } 
 return info; 
 }

如果大家去查查引入就知道我们自定义relm要实现一个叫做doGetAuthorizationInfo()的方法，它的作用是查询授权信息，我们注意加粗的2行，发现其实cache的put方法其实才是cache存储的核心类，其实现都在cache中，所以我们需要实现自己的cache，创建RedisCache类

package com.tgb.itoo.authority.cache;
 
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 
 
 import org.apache.shiro.cache.Cache;
 import org.apache.shiro.cache.CacheException;
 import org.apache.shiro.util.CollectionUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 public class RedisCache<K,V> implements Cache<K,V> {
 
 	private Logger logger = LoggerFactory.getLogger(this.getClass());
 	
 	/**
 * The wrapped Jedis instance.
 */
 	private RedisManager cache;
 	
 	/**
 	 * The Redis key prefix for the sessions 
 	 */
 	private String keyPrefix = "shiro_redis_session:";
 	
 	/**
 	 * Returns the Redis session keys
 	 * prefix.
 	 * @return The prefix
 	 */
 	public String getKeyPrefix() {
 		return keyPrefix;
 	}
 
 	/**
 	 * Sets the Redis sessions key 
 	 * prefix.
 	 * @param keyPrefix The prefix
 	 */
 	public void setKeyPrefix(String keyPrefix) {
 		this.keyPrefix = keyPrefix;
 	}
 	
 	/**
 	 * 通过一个JedisManager实例构造RedisCache
 	 */
 	public RedisCache(RedisManager cache){
 		 if (cache == null) {
 	 throw new IllegalArgumentException("Cache argument cannot be null.");
 	 }
 	 this.cache = cache;
 	}
 	
 	/**
 	 * Constructs a cache instance with the specified
 	 * Redis manager and using a custom key prefix.
 	 * @param cache The cache manager instance
 	 * @param prefix The Redis key prefix
 	 */
 	public RedisCache(RedisManager cache, 
 				String prefix){
 		 
 		this( cache );
 		
 		// set the prefix
 		this.keyPrefix = prefix;
 	}
 	
 	/**
 	 * 获得byte[]型的key
 	 * @param key
 	 * @return
 	 */
 	private byte[] getByteKey(K key){
 		if(key instanceof String){
 			String preKey = this.keyPrefix + key;
 		return preKey.getBytes();
 	}else{
 		return SerializeUtils.serialize(key);
 	}
 	}
 	
 	@Override
 	public V get(K key) throws CacheException {
 		logger.debug("根据key从Redis中获取对象 key [" + key + "]");
 		try {
 			if (key == null) {
 	 return null;
 	 }else{
 	 	byte[] rawValue = cache.get(getByteKey(key));
 	 	@SuppressWarnings("unchecked")
 				V value = (V)SerializeUtils.deserialize(rawValue);
 	 	return value;
 	 }
 		} catch (Throwable t) {
 			throw new CacheException(t);
 		}
 
 	}
 
 	@Override
 	public V put(K key, V value) throws CacheException {
 		logger.debug("根据key从存储 key [" + key + "]");
 		 try {
 			 	cache.set(getByteKey(key), SerializeUtils.serialize(value));
 	 return value;
 	 } catch (Throwable t) {
 	 throw new CacheException(t);
 	 }
 	}
 
 	@Override
 	public V remove(K key) throws CacheException {
 		logger.debug("从redis中删除 key [" + key + "]");
 		try {
 V previous = get(key);
 cache.del(getByteKey(key));
 return previous;
 } catch (Throwable t) {
 throw new CacheException(t);
 }
 	}
 
 	@Override
 	public void clear() throws CacheException {
 		logger.debug("从redis中删除所有元素");
 		try {
 cache.flushDB();
 } catch (Throwable t) {
 throw new CacheException(t);
 }
 	}
 
 	@Override
 	public int size() {
 		try {
 			Long longSize = new Long(cache.dbSize());
 return longSize.intValue();
 } catch (Throwable t) {
 throw new CacheException(t);
 }
 	}
 
 	@SuppressWarnings("unchecked")
 	@Override
 	public Set<K> keys() {
 		try {
 Set<byte[]> keys = cache.keys(this.keyPrefix + "*");
 if (CollectionUtils.isEmpty(keys)) {
 	return Collections.emptySet();
 }else{
 	Set<K> newKeys = new HashSet<K>();
 	for(byte[] key:keys){
 		newKeys.add((K)key);
 	}
 	return newKeys;
 }
 } catch (Throwable t) {
 throw new CacheException(t);
 }
 	}
 
 	@Override
 	public Collection<V> values() {
 		try {
 Set<byte[]> keys = cache.keys(this.keyPrefix + "*");
 if (!CollectionUtils.isEmpty(keys)) {
 List<V> values = new ArrayList<V>(keys.size());
 for (byte[] key : keys) {
 @SuppressWarnings("unchecked")
 					V value = get((K)key);
 if (value != null) {
 values.add(value);
 }
 }
 return Collections.unmodifiableList(values);
 } else {
 return Collections.emptyList();
 }
 } catch (Throwable t) {
 throw new CacheException(t);
 }
 	}
 }

最后修改spring配置文件

<bean id="securityManager" class="org.apache.shiro.web.mgt.DefaultWebSecurityManager">
 		<property name="realm" ref="shiroRealm"></property>
 		<property name="sessionMode" value="http"></property>
 		<property name="subjectFactory" ref="casSubjectFactory"></property>
 		
 		
 
 		
 		<property name="cacheManager" ref="redisCacheManager" />
 
 		
 		<property name="sessionManager" ref="sessionManager"></property>
 	</bean>

这样就完成了整个shiro集群的配置

[Apache shiro_ _ shiro]: http://blog.csdn.net/lishehe/article/details/45218251
[Apache shiro_ _ shiro _INI]: http://blog.csdn.net/lishehe/article/details/45218605
[Apache shiro_ _shiro_Shiro Authentication]: http://blog.csdn.net/lishehe/article/details/45219023
[Apache shiro_ _shiro_Authentication_--]: http://blog.csdn.net/lishehe/article/details/45219483
[Apache shiro_ _session]: http://blog.csdn.net/lishehe/article/details/45223477
[Apache shiro_ _session_---Session]: http://blog.csdn.net/lishehe/article/details/45223823
[Apache shiro_---cache]: http://blog.csdn.net/lishehe/article/details/45224181
[Apache shiro_ _ web_session_3]: http://blog.csdn.net/lishehe/article/details/45224591