Read a zip file inside zip file

Question

I have zip file which is inside a folder in zip file please suggest me how to read it using zip input stream.

E.G.:

abc.zip
    |
      documents/b         


        

Answer 1

I have written a code that can unzip all zip files inside a zip file. It can even unzip to n levels of compression. Like for example if you had a zip file inside a zip, inside a zip ( and so on) it would extract all of them. Use the zipFileExtract method of this class and pass the source zip file and destination directory as an argument.

import java.io.*;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.*;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;

public class RecursiveFileExtract {
    private static final int BUFFER_SIZE = 4096;
    private static Queue current;
    private static List visited;

    public static void zipFileExtract(File sourceZipFile, File destinationDirectory) {
        Path temp = null;
        if(!destinationDirectory.exists())
        {
            destinationDirectory.mkdirs();
        }
        try {
            temp = Files.move(Paths.get(sourceZipFile.getAbsolutePath()), Paths.get(destinationDirectory.getAbsolutePath()+File.separator+sourceZipFile.getName()));
        } catch (IOException e) {
            e.printStackTrace();
        }
        File zipFile = new File(temp.toAbsolutePath().toString());
        current = new ConcurrentLinkedQueue<>();
        visited = new ArrayList<>();
        current.add(zipFile);
        do {
            unzipCurrent();
            zipFinder(destinationDirectory);
        }
        while (!current.isEmpty());
    }

    private static void zipFinder(File directory) {
        try {
            if (directory != null) {
                File fileArray[] = directory.listFiles();
                if (fileArray != null) {
                    for (File file : fileArray) {
                        if (file != null) {
                            if (file.isDirectory()) {
                                zipFinder(file);
                            } else {
                                if (file.getName().endsWith(".zip")) {
                                    if (!visited.contains(file)) {
                                        current.add(file);
                                    }
                                }
                            }
                        }
                    }
                }
            }
        } catch (Exception e) {
            System.out.println(e.getLocalizedMessage());
        }
    }

    private static void unzipCurrent() {
        try {
            while (!current.isEmpty()) {
                File file = current.remove();
                visited.add(file);
                File zipDirectory = new File(file.getParentFile().getAbsolutePath());
                unzip(file.getAbsolutePath(), zipDirectory.getAbsolutePath());
            }
        } catch (Exception e) {
            System.out.println(e.getLocalizedMessage());
        }
    }

    public static void unzip(String zipFilePath, String destDirectory) {
        try {
            ZipInputStream zipIn = new ZipInputStream(new FileInputStream(zipFilePath));
            ZipEntry entry = zipIn.getNextEntry();

            while (entry != null) {
                String filePath = destDirectory + File.separator + entry.getName();
                if (!entry.isDirectory()) {
                    extractFile(zipIn, filePath);
                } else {

                    File dir = new File(filePath);
                    Boolean result = dir.mkdir();
                }
                zipIn.closeEntry();
                entry = zipIn.getNextEntry();
            }
            zipIn.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private static void extractFile(ZipInputStream zipIn, String filePath) {
        try {
            File file = new File(filePath);
            File parentFile = file.getParentFile();
            if (!parentFile.exists()) {
                Boolean result = parentFile.mkdirs();
                if (!result) {
                    throw new Exception();
                }
            }
            BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(filePath));
            byte[] bytesIn = new byte[BUFFER_SIZE];
            int read = 0;
            while ((read = zipIn.read(bytesIn)) != -1) {
                bos.write(bytesIn, 0, read);
            }
            bos.close();
        } catch (Exception e) {
           System.out.println(e.getLocalizedMessage());
        }
    }
}