ru.mystamps.web.service.FilesystemImagePersistenceStrategy.java Source code

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Here is the source code for ru.mystamps.web.service.FilesystemImagePersistenceStrategy.java

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/*
 * Copyright (C) 2009-2017 Slava Semushin <slava.semushin@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */
package ru.mystamps.web.service;

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;

import javax.annotation.PostConstruct;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.springframework.web.multipart.MultipartFile;

import ru.mystamps.web.dao.dto.ImageDto;
import ru.mystamps.web.dao.dto.ImageInfoDto;
import ru.mystamps.web.service.dto.FsImageDto;
import ru.mystamps.web.service.exception.ImagePersistenceException;

public class FilesystemImagePersistenceStrategy implements ImagePersistenceStrategy {
    private static final Logger LOG = LoggerFactory.getLogger(FilesystemImagePersistenceStrategy.class);

    private final File storageDir;

    public FilesystemImagePersistenceStrategy(String storageDir) {
        this.storageDir = new File(storageDir);
    }

    @PostConstruct
    public void init() {
        LOG.info("Images will be saved into {} directory", storageDir);

        if (!storageDir.exists()) { // NOPMD: ConfusingTernary (it's ok for me)
            LOG.warn("Directory '{}' doesn't exist! Image uploading won't work.", storageDir);

        } else if (!storageDir.canWrite()) {
            LOG.warn("Directory '{}' exists but isn't writable for the current user! "
                    + "Image uploading won't work.", storageDir);
        }
    }

    @Override
    public void save(MultipartFile file, ImageInfoDto image) {
        try {
            Path dest = generateFilePath(storageDir, image);
            writeToFile(file, dest);

            LOG.info("Image's data was written into file {}", dest);

        } catch (IOException ex) {
            throw new ImagePersistenceException(ex);
        }
    }

    @Override
    public ImageDto get(ImageInfoDto image) {
        return get(storageDir, image);
    }

    // protected to allow spying
    protected Path generateFilePath(File dir, ImageInfoDto image) {
        return new File(dir, generateFileName(image)).toPath();
    }

    // protected to allow spying
    protected void writeToFile(MultipartFile file, Path dest) throws IOException {
        // we can't use file.transferTo(dest) there because it creates file
        // relatively to directory from spring.http.multipart.location
        // in application.properties
        // See for details: https://jira.spring.io/browse/SPR-12650
        Files.copy(file.getInputStream(), dest);
    }

    // protected to allow spying
    protected boolean exists(Path path) {
        return Files.exists(path);
    }

    // protected to allow spying
    protected byte[] toByteArray(Path dest) throws IOException {
        return Files.readAllBytes(dest);
    }

    private ImageDto get(File dir, ImageInfoDto image) {
        Path dest = generateFilePath(dir, image);
        if (!exists(dest)) {
            LOG.warn("Found image without content: #{} ({} doesn't exist)", image.getId(), dest);
            return null;
        }

        try {
            byte[] content = toByteArray(dest);
            return new FsImageDto(image, content);

        } catch (IOException ex) {
            throw new ImagePersistenceException(ex);
        }
    }

    private static String generateFileName(ImageInfoDto image) {
        // TODO(performance): specify initial capacity explicitly
        return new StringBuilder().append(image.getId()).append('.').append(image.getType().toLowerCase())
                .toString();
    }

}