strolch/agent/src/main/java/li/strolch/policy/StrolchPolicy.java

101 lines
3.1 KiB
Java

/*
* Copyright 2015 Robert von Burg <eitch@eitchnet.ch>
*
* 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 li.strolch.policy;
import static li.strolch.model.StrolchModelConstants.PolicyConstants.PARAM_ORDER;
import li.strolch.agent.api.ComponentContainer;
import li.strolch.agent.api.StrolchComponent;
import li.strolch.model.Order;
import li.strolch.model.activity.IActivityElement;
import li.strolch.persistence.api.StrolchTransaction;
import li.strolch.service.api.Command;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Interface for all Strolch policies, which are instantiated by the {@link PolicyHandler}
*
* @author Robert von Burg <eitch@eitchnet.ch>
*/
public abstract class StrolchPolicy {
protected static final Logger logger = LoggerFactory.getLogger(StrolchPolicy.class);
private final ComponentContainer container;
private final StrolchTransaction tx;
/**
* Instantiate a new {@link StrolchPolicy}
*
* @param tx the transaction for this policy
*/
public StrolchPolicy(StrolchTransaction tx) {
this.container = tx.getContainer();
this.tx = tx;
}
/**
* Returns true if the given component is registered on th container
*
* @param clazz the type of component to check for
* @return true if the component is available
*/
public boolean hasComponent(Class<?> clazz) {
return this.container.hasComponent(clazz);
}
/**
* Allows the concrete {@link Command} implementation access to {@link StrolchComponent StrolchComponents} at
* runtime
*
* @param clazz the type of component to be returned
* @return the component with the given {@link Class} which is registered on the {@link ComponentContainer}
* @throws IllegalArgumentException if the component with the given class does not exist
*/
protected <V> V getComponent(Class<V> clazz) throws IllegalArgumentException {
return this.container.getComponent(clazz);
}
/**
* @return the container
*/
protected ComponentContainer getContainer() {
return this.container;
}
/**
* Returns the {@link StrolchTransaction} bound to this {@link Command}'s runtime
*
* @return the {@link StrolchTransaction} bound to this {@link Command}'s runtime
*/
protected StrolchTransaction tx() {
return this.tx;
}
protected Order getOrder(IActivityElement element) {
return tx().getOrderByRelation(element.getRootElement(), PARAM_ORDER, true);
}
/**
* @see Command#undo()
*/
public void undo() {
// empty implementation
}
}