spring boot整合redis,实现shiro的CacheManager

时间:2022-11-16 20:35:03

接着上一篇博客来讲:Spring Boot整合jpa,Shiro进行权限管理

Shiro默认整合了EhCache,来实现缓存,如果我们想用redis替换EhCache来实现缓存怎么做了?我们可以从Shiro的源码来找到一些端倪。我们可以模拟EhCacheManager的实现方式,EhCacheManager类定义如下:

public class EhCacheManager implements CacheManager, Initializable, Destroyable {

}

我们从上面的代码可以看到,最终要的是实现了CacheManager接口,该接口很简单,只有一个方法:

public interface CacheManager {

/**
* Acquires the cache with the specified <code>name</code>. If a cache does not yet exist with that name, a new one
* will be created with that name and returned.
*
* @param name the name of the cache to acquire.
* @return the Cache with the given name
* @throws CacheException if there is an error acquiring the Cache instance.
*/
public <K, V> Cache<K, V> getCache(String name) throws CacheException;
}

从上面的注释中,我们可以发现,这个接口需要一个Cache,通过name来获取Cache,首先,我们来实现CacheManager这个接口

@Service
public class RedisCacheManager implements CacheManager {

@Autowired
private RedisTemplate redisTemplate; // RedisTemplate,如果不明白怎么使用的,请参考http://blog.csdn.net/liuchuanhong1/article/details/54601037

@Override
public <K, V> Cache<K, V> getCache(String name) throws CacheException {
System.out.println("name:"+name);
return new RedisCache<K, V>(120, redisTemplate);// 为了简化代码的编写,此处直接new一个Cache
}

}


下面,我们来看下这个Cache怎么写

package com.chhliu.springboot.shiro.cache;

import java.util.Collection;
import java.util.Set;
import java.util.concurrent.TimeUnit;

import org.apache.shiro.cache.Cache;
import org.apache.shiro.cache.CacheException;
import org.springframework.data.redis.core.RedisTemplate;

public class RedisCache<K, V> implements Cache<K, V> {

private long expireTime = 120;// 缓存的超时时间,单位为s

private RedisTemplate<K, V> redisTemplate;// 通过构造方法注入该对象

public RedisCache() {
super();
}

public RedisCache(long expireTime, RedisTemplate<K, V> redisTemplate) {
super();
this.expireTime = expireTime;
this.redisTemplate = redisTemplate;
}

/**
* 通过key来获取对应的缓存对象
* 通过源码我们可以发现,shiro需要的key的类型为Object,V的类型为AuthorizationInfo对象
*/
@Override
public V get(K key) throws CacheException {
return redisTemplate.opsForValue().get(key);
}

/**
* 将权限信息加入缓存中
*/
@Override
public V put(K key, V value) throws CacheException {
redisTemplate.opsForValue().set(key, value, this.expireTime, TimeUnit.SECONDS);
return value;
}

/**
* 将权限信息从缓存中删除
*/
@Override
public V remove(K key) throws CacheException {
V v = redisTemplate.opsForValue().get(key);
redisTemplate.opsForValue().getOperations().delete(key);
return v;
}

@Override
public void clear() throws CacheException {

}

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

@Override
public Set<K> keys() {
return null;
}

@Override
public Collection<V> values() {
return null;
}

}

这两步完成之后,就是需要将原来的EhCacheManager的配置换成RedisCacheManager了

@Bean
public DefaultWebSessionManager configWebSessionManager(){
DefaultWebSessionManager manager = new DefaultWebSessionManager();
manager.setCacheManager(cacheManager);// 换成Redis的缓存管理器
manager.setSessionDAO(sessionDao);
manager.setDeleteInvalidSessions(true);
manager.setGlobalSessionTimeout(sessionDao.getExpireTime());
manager.setSessionValidationSchedulerEnabled(true);

return manager;
}

通过上面的几步,我们就实现了用Redis来缓存Shiro的权限等相关信息