org.springframework.webflow.engine.FlowVariable Maven / Gradle / Ivy
/*
* Copyright 2004-2007 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.engine;
import java.io.Serializable;
import org.springframework.core.style.ToStringCreator;
import org.springframework.util.Assert;
import org.springframework.webflow.execution.RequestContext;
import org.springframework.webflow.execution.ScopeType;
/**
* A value object that defines a specification for a flow variable. Encapsulates information about the variable and the
* behavior necessary to create a new variable instance in a flow execution scope.
*
* @author Keith Donald
*/
public abstract class FlowVariable extends AnnotatedObject implements Serializable {
/**
* The variable name.
*/
private String name;
/**
* The variable scope.
*/
private ScopeType scope;
/**
* Creates a new flow variable.
* @param name the variable name
* @param scope the variable scope type
*/
public FlowVariable(String name, ScopeType scope) {
Assert.hasText(name, "The variable name is required");
Assert.notNull(scope, "The variable scope type is required");
this.name = name;
this.scope = scope;
}
/**
* Returns the name of this variable.
*/
public String getName() {
return name;
}
/**
* Returns the scope of this variable.
*/
public ScopeType getScope() {
return scope;
}
// name and scope based equality
public boolean equals(Object o) {
if (!(o instanceof FlowVariable)) {
return false;
}
FlowVariable other = (FlowVariable) o;
return name.equals(other.name) && scope.equals(other.scope);
}
public int hashCode() {
return name.hashCode() + scope.hashCode();
}
/**
* Creates a new instance of this flow variable in the configured scope.
* @param context the flow execution request context
*/
public final void create(RequestContext context) {
scope.getScope(context).put(name, createVariableValue(context));
}
/**
* Hook method that needs to be implemented by subclasses to calculate the value of this flow variable based on the
* information available in the request context.
* @param context the flow execution request context
* @return the flow variable value
*/
protected abstract Object createVariableValue(RequestContext context);
public String toString() {
return new ToStringCreator(this).append("name", name).append("scope", scope).toString();
}
}