org.opentripplanner.datastore.file.ZipFileDataSource Maven / Gradle / Ivy

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package org.opentripplanner.datastore.file;

import org.opentripplanner.datastore.CompositeDataSource;
import org.opentripplanner.datastore.DataSource;
import org.opentripplanner.datastore.FileType;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Enumeration;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;


/**
 * This is a wrapper around a ZipFile, it can be used to read the content, but
 * not write to it. The {@link #asOutputStream()} is throwing an exception.
 */
public class ZipFileDataSource extends AbstractFileDataSource implements CompositeDataSource {
    private static final Logger LOG = LoggerFactory.getLogger(ZipFileDataSource.class);

    private boolean contentLoaded = false;
    private ZipFile zipFile;
    private final Collection content = new ArrayList<>();

    public ZipFileDataSource(File file, FileType type) {
        super(file, type);
    }

    @Override
    public void close() {
        try {
            if(zipFile != null) {
                zipFile.close();
                zipFile = null;
            }
        }
        catch (IOException e) {
            LOG.error(path() + " close failed. Details: " + e.getLocalizedMessage(), e);
        }
    }

    @Override
    public boolean isWritable() {
        return false;
    }

    @Override
    public Collection content() {
        loadContent();
        return content;
    }

    @Override
    public DataSource entry(String name) {
        loadContent();
        return content.stream()
                .filter(it -> it.name().equals(name))
                .findFirst()
                .orElse(null);
    }

    /**
     * @return the internal zip file if still open. {@code null} is return if the file is closed.
     */
    ZipFile zipFile() {
        return zipFile;
    }

    private void loadContent() {
        // Load content once
        if(contentLoaded) { return; }
        contentLoaded = true;

        try {
            // The get name on ZipFile returns the full path, we want just the name.
            this.zipFile = new ZipFile(file, ZipFile.OPEN_READ);

            Enumeration entries = zipFile.entries();

            while (entries.hasMoreElements()) {
                ZipEntry entry = entries.nextElement();
                content.add(new ZipFileEntryDataSource(this, entry));
            }
        }
        catch (IOException e) {
            throw new RuntimeException(
                    "Failed to load " + path() + ": " + e.getLocalizedMessage(),
                    e
            );
        }
    }
}