Compress directory into a zipfile with Commons IO

Question

I am a beginner at programming with Java and am currently writing an application which must be able to compress and decompress .zip files. I can use the following code to decompress a zipfile in Java using the built-in Java zip functionality as well as the Apache Commons IO library:

public static void decompressZipfile(String file, String outputDir) throws IOException {
    if (!new File(outputDir).exists()) {
        new File(outputDir).mkdirs();
    }
    ZipFile zipFile = new ZipFile(file);
    Enumeration<? extends ZipEntry> entries = zipFile.entries();
    while (entries.hasMoreElements()) {
        ZipEntry entry = entries.nextElement();
        File entryDestination = new File(outputDir, entry.getName());
        if (entry.isDirectory()) {
            entryDestination.mkdirs();
        } else {
            InputStream in = zipFile.getInputStream(entry);
            OutputStream out = new FileOutputStream(entryDestination);
            IOUtils.copy(in, out);
            IOUtils.closeQuietly(in);
            IOUtils.closeQuietly(out);
        }
    }
}

How would I go about creating a zipfile from a directory using no external libraries other than what I am already using? (Java standard libraries and Commons IO)

Stace

In you case the zip part is being done by java.util.Zip commons-IO is just providing a utility to close files. Are you looking at a solution like the above? – Thrash

Yes, I am looking for a solution which uses only provided Java libraries and/or Commons-IO, and no other external dependencies. I have edited the question text to be more clear about this. I am rather new and, as this code is from another SE question that presented it as the "Commons-IO method of unzipping a zipfile", I mistakenly thought that the functionality was provided by Commons-IO. – Stace

Answer 1

The following method(s) seem to successfully compress a directory recursively:

public static void compressZipfile(String sourceDir, String outputFile) throws IOException, FileNotFoundException {
    ZipOutputStream zipFile = new ZipOutputStream(new FileOutputStream(outputFile));
    compressDirectoryToZipfile(sourceDir, sourceDir, zipFile);
    IOUtils.closeQuietly(zipFile);
}

private static void compressDirectoryToZipfile(String rootDir, String sourceDir, ZipOutputStream out) throws IOException, FileNotFoundException {
    for (File file : new File(sourceDir).listFiles()) {
        if (file.isDirectory()) {
            compressDirectoryToZipfile(rootDir, sourceDir + File.separator + file.getName(), out);
        } else {
            ZipEntry entry = new ZipEntry(sourceDir.replace(rootDir, "") + file.getName());
            out.putNextEntry(entry);

            FileInputStream in = new FileInputStream(sourceDir + file.getName());
            IOUtils.copy(in, out);
            IOUtils.closeQuietly(in);
        }
    }
}

As seen in my compression code snippet, I'm using IOUtils.copy() to handle stream data transfer.

Stace

There's a error on line 10, the File.separator has been put in one concat too late. – Buenrostro

this line has one error .. in this line FileInputStream in = new FileInputStream(sourceDir + file.getName()); it should be FileInputStream in = new FileInputStream(sourceDir+File.separator + file.getName()); – Hayton

Answer 2

I fix above error and it works perfect.

    public static void compressZipfile(String sourceDir, String outputFile) throws IOException, FileNotFoundException {
    ZipOutputStream zipFile = new ZipOutputStream(new FileOutputStream(outputFile));
    Path srcPath = Paths.get(sourceDir);
    compressDirectoryToZipfile(srcPath.getParent().toString(), srcPath.getFileName().toString(), zipFile);
    IOUtils.closeQuietly(zipFile);
}

private static void compressDirectoryToZipfile(String rootDir, String sourceDir, ZipOutputStream out) throws IOException, FileNotFoundException {
    String dir = Paths.get(rootDir, sourceDir).toString();
    for (File file : new File(dir).listFiles()) {
        if (file.isDirectory()) {
            compressDirectoryToZipfile(rootDir, Paths.get(sourceDir,file.getName()).toString(), out);
        } else {
            ZipEntry entry = new ZipEntry(Paths.get(sourceDir,file.getName()).toString());
            out.putNextEntry(entry);

            FileInputStream in = new FileInputStream(Paths.get(rootDir, sourceDir, file.getName()).toString());
            IOUtils.copy(in, out);
            IOUtils.closeQuietly(in);
        }
    }
}

Nada

possible duplicate of #23318883 – Tarrsus

Answer 3

Looks like the answer is a bit outdated. Refreshed it for latest Java for now. Also in ZIP file file names will be relative to given folder for compression. In original answer they were absolute with full paths.

import org.apache.commons.io.IOUtils;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.URI;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.List;
import java.util.stream.Collectors;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

public class Zipper {

    public static void compressFolder(String sourceDir, String outputFile) throws IOException {
        try (ZipOutputStream zipOutputStream = new ZipOutputStream(new FileOutputStream(outputFile))) {
            compressDirectoryToZipFile((new File(sourceDir)).toURI(), new File(sourceDir), zipOutputStream);
        }
    }

    private static void compressDirectoryToZipFile(URI basePath, File dir, ZipOutputStream out) throws IOException {
        List<File> fileList = Files.list(Paths.get(dir.getAbsolutePath()))
                .map(Path::toFile)
                .collect(Collectors.toList());
        for (File file : fileList) {
            if (file.isDirectory()) {
                compressDirectoryToZipFile(basePath, file, out);
            } else {
                out.putNextEntry(new ZipEntry(basePath.relativize(file.toURI()).getPath()));
                try (FileInputStream in = new FileInputStream(file)) {
                    IOUtils.copy(in, out);
                }
            }
        }
    }

}

Aright

Answer 4

Full class ZipUtils based on answers above.

public final class ZipUtils {

    private ZipUtils() {
    }

    // For testing
    public static void main(String[] args) throws IOException {
        compressFile(new File("./file.test"), new File("test1.zip"));
        compressDirectory(new File("./test1"), new File("test2.zip"));
        extractArchive(new File("./test2"), new File("test3.zip"));
    }

    public static void compressDirectory(File sourceDirectory, File zipFile) throws IOException {
        Preconditions.checkState(sourceDirectory.exists(), "Source directory is not exists: %s", sourceDirectory);
        try (ZipOutputStream out = new ZipOutputStream(new FileOutputStream(zipFile))) {
            compressDirectory(sourceDirectory.getAbsoluteFile(), sourceDirectory, out);
        }
    }

    private static void compressDirectory(File rootDir, File sourceDir, ZipOutputStream out) throws IOException {
        for (File file : Preconditions.checkNotNull(sourceDir.listFiles())) {
            if (file.isDirectory()) {
                compressDirectory(rootDir, new File(sourceDir, file.getName()), out);
            } else {
                String zipEntryName = getRelativeZipEntryName(rootDir, file);
                compressFile(out, file, zipEntryName);
            }
        }
    }

    private static String getRelativeZipEntryName(File rootDir, File file) {
        return StringUtils.removeStart(file.getAbsolutePath(), rootDir.getAbsolutePath());
    }

    public static void compressFile(File file, File zipFile) throws IOException {
        try (ZipOutputStream out = new ZipOutputStream(new FileOutputStream(zipFile))) {
            compressFile(out, file, file.getName());
        }
    }

    private static void compressFile(ZipOutputStream out, File file, String zipEntityName) throws IOException {
        ZipEntry entry = new ZipEntry(zipEntityName);
        out.putNextEntry(entry);

        try (FileInputStream in = new FileInputStream(file)) {
            IOUtils.copy(in, out);
        }
    }

    public static void extractArchive(File targetDirectory, File zipFile) throws IOException {
        try (ZipInputStream zis = new ZipInputStream(new FileInputStream(zipFile))) {
            extractStream(targetDirectory, zis);
        }
    }

    private static void extractStream(File targetDirectory, ZipInputStream zis) throws IOException {
        ZipEntry zipEntry = zis.getNextEntry();
        while (zipEntry != null) {
            extractEntry(targetDirectory, zis, zipEntry);
            zipEntry = zis.getNextEntry();
        }
        zis.closeEntry();
    }

    private static void extractEntry(File targetDirectory, ZipInputStream zis, ZipEntry zipEntry) throws IOException {
        File newFile = newFile(targetDirectory, zipEntry);
        if (zipEntry.isDirectory()) {
            FileUtils.forceMkdir(newFile);
        } else {
            FileUtils.forceMkdirParent(newFile);
            try (FileOutputStream fos = new FileOutputStream(newFile)) {
                IOUtils.copy(zis, fos);
            }
        }
    }

    private static File newFile(File targetDirectory, ZipEntry zipEntry) throws IOException {
        File targetFile = new File(targetDirectory, zipEntry.getName());

        String targetDirPath = targetDirectory.getCanonicalPath();
        String targetFilePath = targetFile.getCanonicalPath();

        if (!targetFilePath.startsWith(targetDirPath + File.separator)) {
            throw new IOException("Entry is outside of the target dir: " + zipEntry.getName());
        }

        return targetFile;
    }
}

Megan

You say "Full Class" yet where are the import statements? What's "Preconditions" referring to? – Triquetrous