com.gwtplatform.dispatch.client.actionhandler.caching.ActionCachingHandler Maven / Gradle / Ivy
/**
* Copyright 2011 ArcBees Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.gwtplatform.dispatch.client.actionhandler.caching;
import com.gwtplatform.dispatch.shared.Action;
import com.gwtplatform.dispatch.shared.Result;
/**
* Default implementation of {@link AbstractCachingClientActionHandler}. It supports {@link Action} caching
*
* TODO Add support for timeout based auto-expiry of cached results?
*
* @param The type of the action extending {@link Action}.
* @param The type of the result extending {@link Result}.
*
* @author Sunny Gupta
*/
public class ActionCachingHandler, R extends Result> extends
AbstractCachingClientActionHandler {
public ActionCachingHandler(Class actionType, Cache cache) {
super(actionType, cache);
}
@Override
protected void postfetch(A action, R result) {
// Check if null result
if (result == null) {
getCache().remove(action);
} else {
// Cache
getCache().put(action, result);
}
}
@SuppressWarnings("unchecked")
@Override
protected R prefetch(A action) {
try {
// Check if Action available in Cache
Object value = super.getCache().get(action);
if (value != null && value instanceof Result) {
return (R) value;
} else {
return null;
}
} catch (Exception e) {
return null;
}
}
}