Ant example source code file (MajoritySelector.java)

This example Ant source code file (MajoritySelector.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Ant tags/keywords

baseselectorcontainer, enumeration, file, file, fileselector, io, majorityselector, majorityselector, string, string, stringbuffer, stringbuffer, util

The MajoritySelector.java source code

/*
 *  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.tools.ant.types.selectors;

import java.io.File;
import java.util.Enumeration;

/**
 * This selector is here just to shake up your thinking a bit. Don't get
 * too caught up in boolean, there are other ways you can evaluate a
 * collection of selectors. This one takes a vote of the selectors it
 * contains, and majority wins. You could also have an "all-but-one"
 * selector, a "weighted-average" selector, and so on. These are left
 * as exercises for the reader (as are the usecases where this would
 * be necessary).
 *
 * @since 1.5
 */
public class MajoritySelector extends BaseSelectorContainer {

    private boolean allowtie = true;

    /**
     * Default constructor.
     */
    public MajoritySelector() {
    }

    /**
     * @return a string describing this object
     */
    public String toString() {
        StringBuffer buf = new StringBuffer();
        if (hasSelectors()) {
            buf.append("{majorityselect: ");
            buf.append(super.toString());
            buf.append("}");
        }
        return buf.toString();
    }

    /**
     * A attribute to specify what will happen if number
     * of yes votes is the same as the number of no votes
     * defaults to true
     *
     * @param tiebreaker the value to give if there is a tie
     */
    public void setAllowtie(boolean tiebreaker) {
        allowtie = tiebreaker;
    }

    /**
     * Returns true (the file is selected) if most of the other selectors
     * agree. In case of a tie, go by the allowtie setting. That defaults
     * to true, meaning in case of a tie, the file is selected.
     *
     * @param basedir the base directory the scan is being done from
     * @param filename is the name of the file to check
     * @param file is a java.io.File object for the filename that the selector
     * can use
     * @return whether the file should be selected or not
     */
    public boolean isSelected(File basedir, String filename, File file) {
        validate();
        int yesvotes = 0;
        int novotes = 0;
        Enumeration e = selectorElements();
        boolean result;

        while (e.hasMoreElements()) {
            result = ((FileSelector) e.nextElement()).isSelected(basedir,
                    filename, file);
            if (result) {
                yesvotes = yesvotes + 1;
            } else {
                novotes = novotes + 1;
            }
        }
        if (yesvotes > novotes) {
            return true;
        } else if (novotes > yesvotes) {
            return false;
        }
        // At this point, we know we have a tie.
        return allowtie;
    }
}