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public class RoleMenuCache implements IClearCache {
private static Map<String, RoleMenu> roleMenuCache = new HashMap<String, RoleMenu>();
...业务代码省略
}
这里主要是替换这个HashMap所以改动就比较小。
public class CacheManager {
private final static Logger logger = LoggerFactory.getLogger(CacheManager.class);
private static Map<String, ICache> caches = new ConcurrentHashMap<>();
private static ICacheStrategy cacheStrategy = new DefaultCacheStategy();
private static String cacheStrategyClass;
@SuppressWarnings("unchecked")
public static synchronized <T extends ICache> T getOrCreateCache(String cacheName, Class<?> keyClass, Class<?> valueCalss) {
T cache = (T) caches.get(cacheName);
if (cache != null) {
return cache;
}
cache = (T) cacheStrategy.createCache(cacheName, keyClass, valueCalss);
caches.put(cacheName, cache);
return cache;
}
@SuppressWarnings("rawtypes")
public static synchronized void destroyCache(String cacheName) {
ICache cache = caches.remove(cacheName);
if (cache != null) {
cache.clear();
}
}
}
public interface ICacheStrategy {
ICache createCache(String name, Class<?> keyClass, Class<?> valueCalss);
void destroyCache(ICache cache);
}
public class DefaultCache<K, V> implements ICache<K, V> {
protected Map<K, V> map;
private String name;
private long maxCacheSize;
private long maxLifetime;
private int cacheSize = 0;
public DefaultCache(String name, long maxSize, long maxLifetime) {
this.name = name;
this.maxCacheSize = maxSize;
this.maxLifetime = maxLifetime;
map = new ConcurrentHashMap<K, V>(103);
}
@Override
public V get(Object key) {
return map.get(key);
}
@Override
public V put(K key, V value) {
return map.put(key, value);
}
@Override
public V remove(Object key) {
return map.remove(key);
}
@Override
public void putAll(Map<? extends K, ? extends V> m) {
map.putAll(m);
}
@Override
public void clear() {
if (map != null) {
map.clear();
}
}
}
对于调用方来说其实就很简单，只需要调用CacheManager即可，还是前面举的RoleMenuCache
public class RoleMenuCache implements IClearCache {
private static Map<String, RoleMenu> roleMenuCache;
static {
roleMenuCache = CacheManager.getOrCreateCache("permissionCache", String.class, RoleMenu.class);
}
...业务代码省略
}
对于老代码的改造还是比较小的，而且这样的好处是以后想换成redis的也很简单，对于业务代码就不需要再修改了。
/**
* 根据key设置map的值
*/
@Override
public V put(K key, V value) {
jedisTemp.hset(name, JSON.toJSONString(key), JSON.toJSONString(value));
return value;
}
这并没啥问题，因为对象转换成json串是正常的。问题是get的时候，我们使用的
CacheManager.getOrCreateCache("permissionCache", String.class, RoleMenu.class);
最终get方法的实现就是这样：
@Override
public V get(Object key) {
String json = jedisTemp.hget(name, JSON.toJSONString(key));
return (V) JSON.parseObject(json, valueClass);
}
问题虽然是解决了，只不过总觉得怪怪的。
http://www.cnblogs.com/5207/p/5788439.html
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原文地址：http://www.cnblogs.com/softidea/p/5789400.html
