org.apache.commons.collections4.functors.ChainedClosure Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.collections4.functors;
import java.io.Serializable;
import java.util.Collection;
import org.apache.commons.collections4.Closure;
/**
* Closure implementation that chains the specified closures together.
*
* @since 3.0
*/
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 the type that the closure acts on
* @param closures the closures to chain, copied, no nulls
* @return the chained closure
* @throws NullPointerException if the closures array is null
* @throws NullPointerException if any closure in the array is null
*/
public static Closure chainedClosure(final Closure... closures) {
FunctorUtils.validate(closures);
if (closures.length == 0) {
return NOPClosure.nopClosure();
}
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 the type that the closure acts on
* @param closures a collection of closures to chain
* @return the chained closure
* @throws NullPointerException if the closures collection is null
* @throws NullPointerException if any closure in the collection is null
*/
@SuppressWarnings("unchecked")
public static Closure chainedClosure(final Collection> closures) {
if (closures == null) {
throw new NullPointerException("Closure collection must not be null");
}
if (closures.size() == 0) {
return NOPClosure.nopClosure();
}
// convert to array like this to guarantee iterator() ordering
final Closure[] cmds = new Closure[closures.size()];
int i = 0;
for (final Closure closure : closures) {
cmds[i++] = closure;
}
FunctorUtils.validate(cmds);
return new ChainedClosure<>(false, cmds);
}
/**
* Hidden constructor for the use by the static factory methods.
*
* @param clone if {@code true} the input argument will be cloned
* @param closures the closures to chain, no nulls
*/
private ChainedClosure(final boolean clone, final Closure... closures) {
super();
iClosures = clone ? FunctorUtils.copy(closures) : closures;
}
/**
* Constructor that performs no validation.
* Use chainedClosure if you want that.
*
* @param closures the closures to chain, copied, no nulls
*/
public ChainedClosure(final Closure... closures) {
this(true, closures);
}
/**
* Execute a list of closures.
*
* @param input the input object passed to each closure
*/
@Override
public void execute(final E input) {
for (final Closure iClosure : iClosures) {
iClosure.execute(input);
}
}
/**
* Gets the closures.
*
* @return a copy of the closures
* @since 3.1
*/
public Closure[] getClosures() {
return FunctorUtils.copy(iClosures);
}
}