/*
* Copyright 2001-2004 The Apache Software Foundation
*
* 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.apache.commons.collections.functors;
import java.io.Serializable;
import java.util.Collection;
import java.util.Iterator;
import org.apache.commons.collections.Closure;
/**
* Closure implementation that chains the specified closures together.
*
* @since Commons Collections 3.0
* @version $Revision: 348444 $ $Date: 2005-11-23 14:06:56 +0000 (Wed, 23 Nov 2005) $
*
* @author Stephen Colebourne
*/
public class ChainedClosure implements Closure, Serializable {
/** Serial version UID */
private static final long serialVersionUID = -3520677225766901240L;
/** The closures to call in turn */
private final Closure[] iClosures;
/**
* Factory method that performs validation and copies the parameter array.
*
* @param closures the closures to chain, copied, no nulls
* @return the <code>chained</code> closure
* @throws IllegalArgumentException if the closures array is null
* @throws IllegalArgumentException if any closure in the array is null
*/
public static Closure getInstance(Closure[] closures) {
FunctorUtils.validate(closures);
if (closures.length == 0) {
return NOPClosure.INSTANCE;
}
closures = FunctorUtils.copy(closures);
return new ChainedClosure(closures);
}
/**
* Create a new Closure that calls each closure in turn, passing the
* result into the next closure. The ordering is that of the iterator()
* method on the collection.
*
* @param closures a collection of closures to chain
* @return the <code>chained</code> closure
* @throws IllegalArgumentException if the closures collection is null
* @throws IllegalArgumentException if any closure in the collection is null
*/
public static Closure getInstance(Collection closures) {
if (closures == null) {
throw new IllegalArgumentException("Closure collection must not be null");
}
if (closures.size() == 0) {
return NOPClosure.INSTANCE;
}
// convert to array like this to guarantee iterator() ordering
Closure[] cmds = new Closure[closures.size()];
int i = 0;
for (Iterator it = closures.iterator(); it.hasNext();) {
cmds[i++] = (Closure) it.next();
}
FunctorUtils.validate(cmds);
return new ChainedClosure(cmds);
}
/**
* Factory method that performs validation.
*
* @param closure1 the first closure, not null
* @param closure2 the second closure, not null
* @return the <code>chained</code> closure
* @throws IllegalArgumentException if either closure is null
*/
public static Closure getInstance(Closure closure1, Closure closure2) {
if (closure1 == null || closure2 == null) {
throw new IllegalArgumentException("Closures must not be null");
}
Closure[] closures = new Closure[] { closure1, closure2 };
return new ChainedClosure(closures);
}
/**
* Constructor that performs no validation.
* Use <code>getInstance</code> if you want that.
*
* @param closures the closures to chain, not copied, no nulls
*/
public ChainedClosure(Closure[] closures) {
super();
iClosures = closures;
}
/**
* Execute a list of closures.
*
* @param input the input object passed to each closure
*/
public void execute(Object input) {
for (int i = 0; i < iClosures.length; i++) {
iClosures[i].execute(input);
}
}
/**
* Gets the closures, do not modify the array.
* @return the closures
* @since Commons Collections 3.1
*/
public Closure[] getClosures() {
return iClosures;
}
}