Ant example source code file (SourceFileScanner.java)

This example Ant source code file (SourceFileScanner.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

file, file, filenamemapper, filenamemapper, fileresource, fileutils, io, resource, resource, resourcefactory, sourcefilescanner, string, string, task, util, vector

The SourceFileScanner.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.util;

import java.io.File;
import java.util.Vector;
import org.apache.tools.ant.Task;
import org.apache.tools.ant.types.Resource;
import org.apache.tools.ant.types.ResourceFactory;
import org.apache.tools.ant.types.resources.FileResource;

/**
 * Utility class that collects the functionality of the various
 * scanDir methods that have been scattered in several tasks before.
 *
 * <p>The only method returns an array of source files. The array is a
 * subset of the files given as a parameter and holds only those that
 * are newer than their corresponding target files.</p>
 *
 */
public class SourceFileScanner implements ResourceFactory {

    // CheckStyle:VisibilityModifier OFF - bc
    protected Task task;
    // CheckStyle:VisibilityModifier ON

    private static final FileUtils FILE_UTILS = FileUtils.getFileUtils();
    private File destDir;     // base directory of the fileset

    /**
     * Construct a new SourceFileScanner.
     * @param task The task we should log messages through.
     */
    public SourceFileScanner(Task task) {
        this.task = task;
    }

    /**
     * Restrict the given set of files to those that are newer than
     * their corresponding target files.
     *
     * @param files   the original set of files.
     * @param srcDir  all files are relative to this directory.
     * @param destDir target files live here. if null file names
     *                returned by the mapper are assumed to be absolute.
     * @param mapper  knows how to construct a target file names from
     *                source file names.
     * @return an array of filenames.
     */
    public String[] restrict(String[] files, File srcDir, File destDir,
                             FileNameMapper mapper) {
        return restrict(files, srcDir, destDir, mapper,
                        FILE_UTILS.getFileTimestampGranularity());
    }

    /**
     * Restrict the given set of files to those that are newer than
     * their corresponding target files.
     *
     * @param files   the original set of files.
     * @param srcDir  all files are relative to this directory.
     * @param destDir target files live here. If null file names
     *                returned by the mapper are assumed to be absolute.
     * @param mapper  knows how to construct a target file names from
     *                source file names.
     * @param granularity The number of milliseconds leeway to give
     *                    before deciding a target is out of date.
     * @return an array of filenames.
     *
     * @since Ant 1.6.2
     */
    public String[] restrict(String[] files, File srcDir, File destDir,
                             FileNameMapper mapper, long granularity) {
        // record destdir for later use in getResource
        this.destDir = destDir;
        Vector v = new Vector();
        for (int i = 0; i < files.length; i++) {
            File src = FILE_UTILS.resolveFile(srcDir, files[i]);
            v.addElement(new Resource(files[i], src.exists(),
                                      src.lastModified(), src.isDirectory()));
        }
        Resource[] sourceresources = new Resource[v.size()];
        v.copyInto(sourceresources);

        // build the list of sources which are out of date with
        // respect to the target
        Resource[] outofdate =
            ResourceUtils.selectOutOfDateSources(task, sourceresources,
                                                 mapper, this, granularity);
        String[] result = new String[outofdate.length];
        for (int counter = 0; counter < outofdate.length; counter++) {
            result[counter] = outofdate[counter].getName();
        }
        return result;
    }

    /**
     * Convenience layer on top of restrict that returns the source
     * files as File objects (containing absolute paths if srcDir is
     * absolute).
     * @param files   the original set of files.
     * @param srcDir  all files are relative to this directory.
     * @param destDir target files live here. If null file names
     *                returned by the mapper are assumed to be absolute.
     * @param mapper  knows how to construct a target file names from
     *                source file names.
     * @return an array of files.
     */
    public File[] restrictAsFiles(String[] files, File srcDir, File destDir,
                                  FileNameMapper mapper) {
        return restrictAsFiles(files, srcDir, destDir, mapper,
                               FILE_UTILS.getFileTimestampGranularity());
    }

    /**
     * Convenience layer on top of restrict that returns the source
     * files as File objects (containing absolute paths if srcDir is
     * absolute).
     *
     * @param files   the original set of files.
     * @param srcDir  all files are relative to this directory.
     * @param destDir target files live here. If null file names
     *                returned by the mapper are assumed to be absolute.
     * @param mapper  knows how to construct a target file names from
     *                source file names.
     * @param granularity The number of milliseconds leeway to give
     *                    before deciding a target is out of date.
     * @return an array of files.
     * @since Ant 1.6.2
     */
    public File[] restrictAsFiles(String[] files, File srcDir, File destDir,
                                  FileNameMapper mapper, long granularity) {
        String[] res = restrict(files, srcDir, destDir, mapper, granularity);
        File[] result = new File[res.length];
        for (int i = 0; i < res.length; i++) {
            result[i] = new File(srcDir, res[i]);
        }
        return result;
    }

    /**
     * Returns resource information for a file at destination.
     * @param name relative path of file at destination.
     * @return data concerning a file whose relative path to destDir is name.
     *
     * @since Ant 1.5.2
     */
    public Resource getResource(String name) {
        return new FileResource(destDir, name);
    }

}