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

The following code snippet lists the entries of a ZIP file inside another ZIP file. Adapt it to your needs. ZipFile uses ZipInputStreams underneath the hood.

The code snippet uses Apache Commons IO, specifically IOUtils.copy.

public static void readInnerZipFile(File zipFile, String innerZipFileEntryName) {
    ZipFile outerZipFile = null;
    File tempFile = null;
    FileOutputStream tempOut = null;
    ZipFile innerZipFile = null;
    try {
        outerZipFile = new ZipFile(zipFile);
        tempFile = File.createTempFile("tempFile", "zip");
        tempOut = new FileOutputStream(tempFile);
        IOUtils.copy( //
                outerZipFile.getInputStream(new ZipEntry(innerZipFileEntryName)), //
                tempOut);
        innerZipFile = new ZipFile(tempFile);
        Enumeration entries = innerZipFile.entries();
        while (entries.hasMoreElements()) {
            ZipEntry entry = entries.nextElement();
            System.out.println(entry);
            // InputStream entryIn = innerZipFile.getInputStream(entry);
        }

    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        // Make sure to clean up your I/O streams
        try {
            if (outerZipFile != null)
                outerZipFile.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        IOUtils.closeQuietly(tempOut);
        if (tempFile != null && !tempFile.delete()) {
            System.out.println("Could not delete " + tempFile);
        }
        try {
            if (innerZipFile != null)
                innerZipFile.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

public static void main(String[] args) {
    readInnerZipFile(new File("abc.zip"), "documents/bcd.zip");
}