org.springframework.webflow.definition.registry.FlowDefinitionHolder Maven / Gradle / Ivy
/*
* Copyright 2004-2008 the original author or authors.
*
* 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 org.springframework.webflow.definition.registry;
import org.springframework.webflow.definition.FlowDefinition;
/**
* A holder holding a reference to a Flow definition. Provides a layer of indirection, enabling things like
* "hot-reloadable" flow definitions.
*
* @see FlowDefinitionRegistry#registerFlowDefinition(FlowDefinitionHolder)
*
* @author Keith Donald
*/
public interface FlowDefinitionHolder {
/**
* Returns the id of the flow definition held by this holder. This is a lightweight method
* callers may call to obtain the id of the flow without triggering full flow definition assembly (which may be an
* expensive operation).
*/
public String getFlowDefinitionId();
/**
* Returns a descriptive string that identifies the source of this FlowDefinition. This is also a lightweight method
* callers may call to obtain the logical resource where the flow definition resides without triggering flow
* definition assembly. Used for informational purposes.
* @return the flow definition resource string
*/
public String getFlowDefinitionResourceString();
/**
* Returns the flow definition held by this holder. Calling this method the first time may trigger flow assembly
* (which may be expensive).
* @throws FlowDefinitionConstructionException if there is a problem constructing the target flow definition
*/
public FlowDefinition getFlowDefinition() throws FlowDefinitionConstructionException;
/**
* Refresh the flow definition held by this holder. Calling this method typically triggers flow re-assembly, which
* may include a refresh from an externalized resource such as a file.
* @throws FlowDefinitionConstructionException if there is a problem constructing the target flow definition
*/
public void refresh() throws FlowDefinitionConstructionException;
/**
* Indicates that the system is being shutdown and any resources flow resources should be released. After this
* method is called, calls to {@link #getFlowDefinition()} are undefined. Should only be called once. May be a no-op
* if the held flow was never constructed to begin with.
*/
public void destroy();
}