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/*
* 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.collections.functors;
import java.io.Serializable;
import java.util.Iterator;
import java.util.Map;
import org.apache.commons.collections.Closure;
import org.apache.commons.collections.Predicate;
/**
* Closure implementation calls the closure whose predicate returns true,
* like a switch statement.
*
* @since Commons Collections 3.0
* @version $Revision$ $Date$
*
* @author Stephen Colebourne
*
* @deprecated Apache Commons Collections version 3.x is being deprecated from AEMaaCS. The upgraded version 4.4 of Commons Collections is already included as replacement. Customers are advised to upgrade to this version of the library. Please note: the package name was changed to org.apache.commons.collections4. Further note that there are AEM APIs currently exposing the old collections classes; these will be updated in upcoming releases.
*/
@Deprecated(since = "2021-04-30")
public class SwitchClosure implements Closure, Serializable {
/**
* Serial version UID
*/
private static final long serialVersionUID = 3518477308466486130L;
/**
* The tests to consider
*/
private final Predicate[] iPredicates;
/**
* The matching closures to call
*/
private final Closure[] iClosures;
/**
* The default closure to call if no tests match
*/
private final Closure iDefault;
/**
* Factory method that performs validation and copies the parameter arrays.
*
* @param predicates array of predicates, cloned, no nulls
* @param closures matching array of closures, cloned, no nulls
* @param defaultClosure the closure to use if no match, null means nop
* @return the chained closure
* @throws IllegalArgumentException if array is null
* @throws IllegalArgumentException if any element in the array is null
*/
public static Closure getInstance(Predicate[] predicates, Closure[] closures, Closure defaultClosure) {
FunctorUtils.validate(predicates);
FunctorUtils.validate(closures);
if (predicates.length != closures.length) {
throw new IllegalArgumentException("The predicate and closure arrays must be the same size");
}
if (predicates.length == 0) {
return (defaultClosure == null ? NOPClosure.INSTANCE : defaultClosure);
}
predicates = FunctorUtils.copy(predicates);
closures = FunctorUtils.copy(closures);
return new SwitchClosure(predicates, closures, defaultClosure);
}
/**
* Create a new Closure that calls one of the closures depending
* on the predicates.
*
* The Map consists of Predicate keys and Closure values. A closure
* is called if its matching predicate returns true. Each predicate is evaluated
* until one returns true. If no predicates evaluate to true, the default
* closure is called. The default closure is set in the map with a
* null key. The ordering is that of the iterator() method on the entryset
* collection of the map.
*
* @param predicatesAndClosures a map of predicates to closures
* @return the switch closure
* @throws IllegalArgumentException if the map is null
* @throws IllegalArgumentException if any closure in the map is null
* @throws ClassCastException if the map elements are of the wrong type
*/
public static Closure getInstance(Map predicatesAndClosures) {
Closure[] closures = null;
Predicate[] preds = null;
if (predicatesAndClosures == null) {
throw new IllegalArgumentException("The predicate and closure map must not be null");
}
if (predicatesAndClosures.size() == 0) {
return NOPClosure.INSTANCE;
}
// convert to array like this to guarantee iterator() ordering
Closure defaultClosure = (Closure) predicatesAndClosures.remove(null);
int size = predicatesAndClosures.size();
if (size == 0) {
return (defaultClosure == null ? NOPClosure.INSTANCE : defaultClosure);
}
closures = new Closure[size];
preds = new Predicate[size];
int i = 0;
for (Iterator it = predicatesAndClosures.entrySet().iterator(); it.hasNext(); ) {
Map.Entry entry = (Map.Entry) it.next();
preds[i] = (Predicate) entry.getKey();
closures[i] = (Closure) entry.getValue();
i++;
}
return new SwitchClosure(preds, closures, defaultClosure);
}
/**
* Constructor that performs no validation.
* Use getInstance if you want that.
*
* @param predicates array of predicates, not cloned, no nulls
* @param closures matching array of closures, not cloned, no nulls
* @param defaultClosure the closure to use if no match, null means nop
*/
public SwitchClosure(Predicate[] predicates, Closure[] closures, Closure defaultClosure) {
super();
iPredicates = predicates;
iClosures = closures;
iDefault = (defaultClosure == null ? NOPClosure.INSTANCE : defaultClosure);
}
/**
* Executes the closure whose matching predicate returns true
*
* @param input the input object
*/
public void execute(Object input) {
for (int i = 0; i < iPredicates.length; i++) {
if (iPredicates[i].evaluate(input) == true) {
iClosures[i].execute(input);
return;
}
}
iDefault.execute(input);
}
/**
* Gets the predicates, do not modify the array.
*
* @return the predicates
* @since Commons Collections 3.1
*/
public Predicate[] getPredicates() {
return iPredicates;
}
/**
* Gets the closures, do not modify the array.
*
* @return the closures
* @since Commons Collections 3.1
*/
public Closure[] getClosures() {
return iClosures;
}
/**
* Gets the default closure.
*
* @return the default closure
* @since Commons Collections 3.1
*/
public Closure getDefaultClosure() {
return iDefault;
}
}