Apache shiro集群实现 （七）分布式集群系统下---cache共享
Apache shiro集群实现 （一） shiro入门介绍
Apache shiro集群实现 （二） shiro 的INI配置
Apache shiro集群实现 （三）shiro身份认证（Shiro Authentication）
Apache shiro集群实现 （四）shiro授权（Authentication）--访问控制
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集群实现（七）分布式集群系统下---cache共享
Apache shiro集群实现 （八） web集群时session同步的3种方法
Apache shiro集群实现 （八） web集群时session同步的3种方法
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
<span style="font-size:18px;"><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" /></span>
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
<span style="font-size:18px;">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;
}
}
</span>
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
<span style="font-size:18px;"> 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;
} </span>
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
<span style="font-size:18px;">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);
}
}
}
</span>
最后修改spring配置文件
<span style="font-size:18px;"><!-- 第三：shiro管理中心类 start-李社河 --> <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> <!-- ehcahe缓存shiro自带 --> <!-- <property name="cacheManager" ref="shiroEhcacheManager"></property> --> <!-- redis缓存 --> <property name="cacheManager" ref="redisCacheManager" /> <!-- sessionManager --> <property name="sessionManager" ref="sessionManager"></property> </bean></span>
这样就完成了整个shiro集群的配置