com.vividsolutions.jts.util.CollectionUtil Maven / Gradle / Ivy
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/*
* The JTS Topology Suite is a collection of Java classes that
* implement the fundamental operations required to validate a given
* geo-spatial data set to a known topological specification.
*
* Copyright (C) 2001 Vivid Solutions
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* For more information, contact:
*
* Vivid Solutions
* Suite #1A
* 2328 Government Street
* Victoria BC V8T 5G5
* Canada
*
* (250)385-6040
* www.vividsolutions.com
*/
package com.vividsolutions.jts.util;
import java.util.*;
/**
* Utilities for processing {@link Collection}s.
*
* @version 1.7
*/
public class CollectionUtil
{
public interface Function {
Object execute(Object obj);
}
/**
* Executes a function on each item in a {@link Collection}
* and returns the results in a new {@link List}
*
* @param coll the collection to process
* @param func the Function to execute
* @return a list of the transformed objects
*/
public static List transform(Collection coll, Function func)
{
List result = new ArrayList();
for (Iterator i = coll.iterator(); i.hasNext(); ) {
result.add(func.execute(i.next()));
}
return result;
}
/**
* Executes a function on each item in a Collection but does
* not accumulate the result
*
* @param coll the collection to process
* @param func the Function to execute
*/
public static void apply(Collection coll, Function func)
{
for (Iterator i = coll.iterator(); i.hasNext(); ) {
func.execute(i.next());
}
}
/**
* Executes a {@link Function} on each item in a Collection
* and collects all the entries for which the result
* of the function is equal to {@link Boolean} true.
*
* @param collection the collection to process
* @param func the Function to execute
* @return a list of objects for which the function was true
*/
public static List select(Collection collection, Function func) {
List result = new ArrayList();
for (Iterator i = collection.iterator(); i.hasNext();) {
Object item = i.next();
if (Boolean.TRUE.equals(func.execute(item))) {
result.add(item);
}
}
return result;
}
}