/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.ambari.view.pig.resources;
import org.apache.ambari.view.ViewContext;
import org.apache.ambari.view.pig.persistence.Storage;
import org.apache.ambari.view.pig.persistence.utils.FilteringStrategy;
import org.apache.ambari.view.pig.persistence.utils.Indexed;
import org.apache.ambari.view.pig.persistence.utils.ItemNotFound;
import org.apache.ambari.view.pig.persistence.utils.StorageUtil;
import java.util.List;
/**
* CRUD resource manager
* @param <T> Data type with ID
*/
abstract public class CRUDResourceManager<T extends Indexed> {
private Storage storage = null;
protected final Class<T> resourceClass;
/**
* Constructor
* @param responseClass model class
*/
public CRUDResourceManager(Class<T> responseClass) {
this.resourceClass = responseClass;
}
// CRUD operations
/**
* Create operation
* @param object object
* @return model object
*/
public T create(T object) {
object.setId(null);
return this.save(object);
}
/**
* Read operation
* @param id identifier
* @return model object
* @throws ItemNotFound
*/
public T read(String id) throws ItemNotFound {
T object = null;
object = getPigStorage().load(this.resourceClass, Integer.parseInt(id));
if (!checkPermissions(object))
throw new ItemNotFound();
return object;
}
/**
* Read all objects
* @param filteringStrategy filtering strategy
* @return list of filtered objects
*/
public List<T> readAll(FilteringStrategy filteringStrategy) {
return getPigStorage().loadAll(this.resourceClass, filteringStrategy);
}
/**
* Update operation
* @param newObject new object
* @param id identifier of previous object
* @return model object
* @throws ItemNotFound
*/
public T update(T newObject, String id) throws ItemNotFound {
newObject.setId(id);
this.save(newObject);
return newObject;
}
/**
* Delete operation
* @param resourceId object identifier
* @throws ItemNotFound
*/
public void delete(String resourceId) throws ItemNotFound {
int id = Integer.parseInt(resourceId);
if (!getPigStorage().exists(this.resourceClass, id)) {
throw new ItemNotFound();
}
getPigStorage().delete(this.resourceClass, id);
}
// UTILS
protected T save(T object) {
getPigStorage().store(object);
return object;
}
protected Storage getPigStorage() {
if (storage == null) {
storage = StorageUtil.getStorage(getContext());
}
return storage;
}
protected abstract boolean checkPermissions(T object);
protected abstract ViewContext getContext();
}