org.flywaydb.core.internal.resource.filesystem.FileSystemResource Maven / Gradle / Ivy

Show more of this group Show more artifacts with this name
Show all versions of flyway-core Show documentation
There is a newer version: 10.15.2
/*
 * Copyright (C) Red Gate Software Ltd 2010-2024
 *
 * 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.flywaydb.core.internal.resource.filesystem;

import lombok.CustomLog;
import org.flywaydb.core.api.FlywayException;
import org.flywaydb.core.api.Location;
import org.flywaydb.core.api.resource.LoadableResource;
import org.flywaydb.core.internal.util.BomStrippingReader;
import org.flywaydb.core.internal.util.FlywayDbWebsiteLinks;

import java.io.*;
import java.nio.channels.Channels;
import java.nio.channels.FileChannel;
import java.nio.charset.Charset;
import java.nio.file.StandardOpenOption;

import static org.flywaydb.core.internal.util.DataUnits.MEGABYTE;

@CustomLog
public class FileSystemResource extends LoadableResource {
    /**
     * The minimum file size (in bytes) as of which to apply streaming, when active. Files smaller than this threshold
     * will not be streamed, regardless of the actual setting.
     */
    private static final long STREAM_MINIMUM_THRESHOLD = MEGABYTE.toBytes(1);
    private final boolean stream;
    private final File file;
    private final String relativePath;
    private final Charset encoding;
    private final boolean detectEncoding;

    public FileSystemResource(Location location, String fileNameWithPath, Charset encoding, boolean stream) {
        this(location, fileNameWithPath, encoding, false, stream);
    }

    public FileSystemResource(Location location, String fileNameWithPath, Charset encoding, boolean detectEncoding, boolean stream) {
        this.file = new File(new File(fileNameWithPath).getPath());
        this.relativePath = location == null ? file.getPath() : location.getPathRelativeToThis(file.getPath()).replace("\\", "/");
        this.encoding = encoding;
        this.detectEncoding = detectEncoding;
        this.stream = stream;
    }

    @Override
    public String getAbsolutePath() {
        return file.getPath();
    }

    @Override
    public String getAbsolutePathOnDisk() {
        return file.getAbsolutePath();
    }

    @Override
    public Reader read() {
        Charset charSet = encoding;
        if (detectEncoding) {
            try {
                charSet = EncodingDetector.detectFileEncoding(file.toPath());
            } catch (FlywayEncodingDetectionException e) {
                LOG.warn("Could not detect file encoding: " + e.getMessage() + "\nThis may cause issues with your deployments." +
                                 " We recommend using a consistent and supported encoding for all your files. See " + FlywayDbWebsiteLinks.FILE_ENCODING_HELP);
            }
        }
        try {
            return Channels.newReader(FileChannel.open(file.toPath(), StandardOpenOption.READ), charSet.newDecoder(), 4096);
        } catch (IOException e) {
            LOG.debug("Unable to load filesystem resource" + file.getPath() + " using FileChannel.open." +
                              " Falling back to FileInputStream implementation. Exception message: " + e.getMessage());
        }

        try {
            return new BufferedReader(new BomStrippingReader(new InputStreamReader(new FileInputStream(file), charSet)));
        } catch (IOException e) {
            throw new FlywayException("Unable to load filesystem resource: " + file.getPath() + " (encoding: " + charSet + ")", e);
        }
    }

    @Override
    public boolean shouldStream() {
        //noinspection RedundantIfStatement
        if (stream && file.length() > STREAM_MINIMUM_THRESHOLD) {
            return true;
        }
        return false;
    }

    /**
     * @return The filename of this resource, without the path.
     */
    @Override
    public String getFilename() {
        return file.getName();
    }

    @Override
    public String getRelativePath() {
        return relativePath;
    }
}