com.cedarsoft.serialization.serializers.jackson.registry.FileBasedObjectsAccess.java Source code

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Here is the source code for com.cedarsoft.serialization.serializers.jackson.registry.FileBasedObjectsAccess.java

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/**
 * Copyright (C) cedarsoft GmbH.
 *
 * Licensed under the GNU General Public License version 3 (the "License")
 * with Classpath Exception; you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at
 *
 *         http://www.cedarsoft.org/gpl3ce
 *         (GPL 3 with Classpath Exception)
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 3 only, as
 * published by the Free Software Foundation. cedarsoft GmbH designates this
 * particular file as subject to the "Classpath" exception as provided
 * by cedarsoft GmbH in the LICENSE file that accompanied this code.
 *
 * This code 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 General Public License
 * version 3 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 3 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact cedarsoft GmbH, 72810 Gomaringen, Germany,
 * or visit www.cedarsoft.com if you need additional information or
 * have any questions.
 */

package com.cedarsoft.serialization.serializers.jackson.registry;

import com.cedarsoft.exceptions.StillContainedException;
import com.cedarsoft.serialization.NotFoundException;
import org.apache.commons.io.FilenameUtils;
import org.apache.commons.io.filefilter.SuffixFileFilter;

import javax.annotation.Nonnull;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileFilter;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.HashSet;
import java.util.Set;

/**
 * Implementation that is based on simple files.
 */
public class FileBasedObjectsAccess implements StreamBasedObjectsAccess {
    @Nonnull

    private final File baseDir;

    @Nonnull

    private final String extension;

    public FileBasedObjectsAccess(@Nonnull File baseDir, @Nonnull String extension) {
        assert baseDir.exists();
        assert baseDir.isDirectory();

        this.baseDir = baseDir;
        this.extension = extension;
    }

    @Nonnull
    @Override
    public Set<? extends String> getIds() throws IOException {
        assert baseDir.exists();
        File[] files = baseDir.listFiles((FileFilter) new SuffixFileFilter(extension));
        if (files == null) {
            throw new FileNotFoundException("Could not list files in " + baseDir.getAbsolutePath());
        }

        Set<String> ids = new HashSet<String>();
        for (File file : files) {
            ids.add(FilenameUtils.getBaseName(file.getName()));
        }

        return ids;
    }

    @Override
    @Nonnull
    public OutputStream openOut(@Nonnull String id) throws FileNotFoundException {
        File file = getFile(id);
        if (file.exists()) {
            throw new StillContainedException(id);
        }
        return new BufferedOutputStream(new FileOutputStream(file));
    }

    @Override
    public OutputStream openOutForUpdate(@Nonnull String id) throws NotFoundException, FileNotFoundException {
        File file = getFile(id);
        if (!file.exists()) {
            throw new NotFoundException(id);
        }
        return new BufferedOutputStream(new FileOutputStream(file));
    }

    @Override
    @Nonnull
    public InputStream getInputStream(@Nonnull String id) throws FileNotFoundException {
        return new BufferedInputStream(new FileInputStream(getFile(id)));
    }

    @Override
    public void delete(@Nonnull String id) throws NotFoundException {
        File file = getFile(id);
        if (!file.exists()) {
            throw new NotFoundException("No entry found for <" + id + ">");
        }

        file.delete();
    }

    @Nonnull
    private File getFile(@Nonnull String id) {
        return new File(baseDir, id + '.' + extension);
    }

    @Nonnull
    public File getBaseDir() {
        return baseDir;
    }
}