org.metafacture.files.DirReader Maven / Gradle / Ivy

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/*
 * Copyright 2013, 2014 Deutsche Nationalbibliothek
 *
 * 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.metafacture.files;

import org.metafacture.framework.FluxCommand;
import org.metafacture.framework.ObjectReceiver;
import org.metafacture.framework.annotations.Description;
import org.metafacture.framework.annotations.In;
import org.metafacture.framework.annotations.Out;
import org.metafacture.framework.helpers.DefaultObjectPipe;

import java.io.File;
import java.io.FilenameFilter;
import java.util.Arrays;

/**
 * Reads a directory and emits all filenames found.
 *
 * @author Markus Michael Geipel
 * @author Fabian Steeg (fsteeg)
 */
@In(String.class)
@Out(String.class)
@Description("Reads a directory and emits all filenames found.")
@FluxCommand("read-dir")
public final class DirReader extends DefaultObjectPipe> {

    private boolean recursive;

    private String filenameFilterPattern;

    /**
     * Creates an instance of {@link DirReader}.
     */
    public DirReader() {
    }

    /**
     * Flags whether the directory should be traversered recursively.
     *
     * @param recursive true if the directory should be traversered recursively,
     *                  otherwise false
     */
    public void setRecursive(final boolean recursive) {
        this.recursive = recursive;
    }

    /**
     * Sets a filename pattern.
     *
     * @param newFilenameFilterPattern the pattern of the filename
     */
    public void setFilenamePattern(final String newFilenameFilterPattern) {
        filenameFilterPattern = newFilenameFilterPattern;
    }

    @Override
    public void process(final String dir) {
        final File file = new File(dir);
        if (file.isDirectory()) {
            dir(file);
        }
        else {
            getReceiver().process(dir);
        }
    }

    private void dir(final File dir) {
        final ObjectReceiver receiver = getReceiver();
        final File[] files = filenameFilterPattern == null ? dir.listFiles() :
                dir.listFiles(new FilenameFilter() {
                    @Override
                    public boolean accept(final File dir, final String name) {
                        return name.matches(filenameFilterPattern);
                    }
                });
        Arrays.sort(files);
        for (final File file : files) {
            if (file.isDirectory()) {
                if (recursive) {
                    dir(file);
                }
            }
            else {
                receiver.process(file.getAbsolutePath());
            }
        }
    }
}