集群部署的落地实现之spring shiro redis 架构第一篇 shiro通过springcache集成redis缓存

本系列文章针对的是使用shiro框架实现的权限管理系统。这样的系统改成集群模式，主要是把shiro更换为集群模式，让shiro管理的session实现共享。本文介绍的就是借助分布式缓存redis来实现用户会话共享。

shiro的缓存体系分为两种情况，一是使用jvm内存缓存MemorySessionDAO，二是使继承CachingSessionDAO实现里面的抽象方法。本文实现的是集群模式，所以只能使用第二种方式。shiro没有自己实现缓存，但是定义好了缓存模板，只要把自定义的缓存管理器cacheManager注入到shiro配置文件即可。好的，接下来问题就是编写缓存管理器了。

仔细看看文章的标题，我们借助springcache来编写cacheManager，这样就不需要完整编写cacheManager了。只要把这个桥梁给适配好即可。但是缓存管理器管理的缓存对象需要自己去完整编写。

不说了，直接上代码。

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.apache.shiro.cache.Cache;
import org.apache.shiro.cache.CacheException;
import org.apache.shiro.cache.CacheManager;
import org.apache.shiro.util.Destroyable;

public class ShiroSpringCacheManager implements CacheManager, Destroyable {
   private static final Logger logger = LogManager.getLogger(ShiroSpringCacheManager.class);
   private org.springframework.cache.CacheManager cacheManager;

   public org.springframework.cache.CacheManager getCacheManager() {
       return cacheManager;
   }

   public void setCacheManager(org.springframework.cache.CacheManager cacheManager) {
       this.cacheManager = cacheManager;
   }

   @Override
   public <K, V> Cache<K, V> getCache(String name) throws CacheException {
       if (logger.isTraceEnabled()) {
           logger.trace("Acquiring ShiroSpringCache instance named [" + name + "]");
       }
       org.springframework.cache.Cache cache = cacheManager.getCache(name);
       return new ShiroSpringCache<K, V>(cache);
   }

   @Override
   public void destroy() throws Exception {
       cacheManager = null;
   }

}

缓存管理器以及缓存对象主要是通过组合方式实现其适配功能

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.apache.shiro.cache.CacheException;
import org.springframework.cache.Cache;
import org.springframework.cache.Cache.ValueWrapper;

@SuppressWarnings("unchecked")
public class ShiroSpringCache<K, V> implements org.apache.shiro.cache.Cache<K, V> {
   private static final Logger logger = LogManager.getLogger(ShiroSpringCache.class);

   private final org.springframework.cache.Cache cache;

   public ShiroSpringCache(Cache cache) {
       if (cache == null) {
           throw new IllegalArgumentException("Cache argument cannot be null.");
       }
       this.cache = cache;
   }

   @Override
   public V get(K key) throws CacheException {
       if (logger.isTraceEnabled()) {
           logger.trace("Getting object from cache [" + this.cache.getName() + "] for key [" + key + "]key type:" + key.getClass());
       }
       ValueWrapper valueWrapper = cache.get(key);
       if (valueWrapper == null) {
           if (logger.isTraceEnabled()) {
               logger.trace("Element for [" + key + "] is null.");
           }
           return null;
       }
       return (V) valueWrapper.get();
   }

   @Override
   public V put(K key, V value) throws CacheException {
       if (logger.isTraceEnabled()) {
           logger.trace("Putting object in cache [" + this.cache.getName() + "] for key [" + key + "]key type:" + key.getClass());
       }
       V previous = get(key);
       cache.put(key, value);
       return previous;
   }

   @Override
   public V remove(K key) throws CacheException {
       if (logger.isTraceEnabled()) {
           logger.trace("Removing object from cache [" + this.cache.getName() + "] for key [" + key + "]key type:" + key.getClass());
       }
       V previous = get(key);
       cache.evict(key);
       return previous;
   }

   @Override
   public void clear() throws CacheException {
       if (logger.isTraceEnabled()) {
           logger.trace("Clearing all objects from cache [" + this.cache.getName() + "]");
       }
       cache.clear();
   }

   @Override
   public int size() {
       return 0;
   }

   @Override
   public Set<K> keys() {
       return Collections.emptySet();
   }

   @Override
   public Collection<V> values() {
       return Collections.emptySet();
   }

   @Override
   public String toString() {
       return "ShiroSpringCache [" + this.cache.getName() + "]";
   }
}

来源：oschina

链接：https://my.oschina.net/osokra/blog/4446546

标签

apache

log4j

集群部署的落地实现之spring shiro redis 架构 第一篇 shiro通过springcache集成redis缓存

集群部署的落地实现之spring shiro redis 架构第一篇 shiro通过springcache集成redis缓存