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Quick ORM implementation based on the UJO objects.
There is a newer version: 1.22
/*
 *  Copyright 2007-2010 Pavel Ponec
 *
 *  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.ujoframework.criterion;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import org.ujoframework.Ujo;
import org.ujoframework.core.UjoComparator;


/**
 * The Criteria class is a simple tool to search UJO objects in the list.
 * This class takes full advantage of architecture UJO objects. See the next sample.
 *  * Person child  = new Person("Pavel", 140.0);
 * Person mother = new Person("Mary", 150.0);
 * Person father = new Person("John", 160.0);
 *
 * child.set(MOTHER, mother);
 * child.set(FATHER, father);
 *
 * List<Person> persons = Arrays.asList(child, mother, father);
 *
 * Criterion<Person> exp = Criterion.newInstance(NAME, "John");
 * UjoComparator<Person> sort = UjoComparator.create(HIGH, NAME);
 * List<Person> result = CriteriaTool.newInstance().select(persons, exp, sort);

 * 
 * @author Pavel Ponec
 * @since 0.90
 */
public class CriteriaTool {

    /** Find the first UJO by an criterion or return NULL if any object was not found. */
    public UJO findFirst(List list, Criterion criterion) {
        for (UJO ujo : list) {
            if (criterion.evaluate(ujo)) {
                return ujo;
            }
        }
        return null;
    }

    /** Create a copy of the list and sort it. */
    public List select(List list, UjoComparator comparator) {
        List result = new ArrayList(list);
        Collections.sort(result, comparator);
        return result;
    }

    /** Create a sublist of a list by an Ujo criterion. */
    public List select(List list, Criterion criterion) {
        return select(list, criterion, null);
    }

    /** Create a sublist of a list by an Ujo criterion. */
    public List select(List list, Criterion criterion, UjoComparator sorting) {
        List result = new ArrayList();
        for (UJO ujo : list) {
            if (criterion.evaluate(ujo)) {
                result.add(ujo);
            }
        }
        if (sorting != null) {
            Collections.sort(result, sorting);
        }

        return result;
    }

    // ----------- STATIC -------------

    /** Create a new instance */
    public static  CriteriaTool newInstance() {
        return new CriteriaTool();
    }

}