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Types that extend and augment the Java Collections Framework.
/* ====================================================================
* The Apache Software License, Version 1.1
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* Copyright (c) 2001-2004 The Apache Software Foundation. All rights
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* any, must include the following acknowledgement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgement may appear in the software itself,
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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: 1.3 $ $Date: 2004/01/14 21:43:09 $
*
* @author Stephen Colebourne
*/
public class ChainedClosure implements Closure, Serializable {
/** Serial version UID */
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 chained
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 chained
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 chained
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 getInstance
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);
}
}
}