Read the zip file in a zip file

Question

I have a zip file that is inside a folder in a zip file, please suggest me read it using the zip input stream.

EG:

abc.zip | documents/bcd.zip 

How to read a zip file in a zip file?

Answer 1

The following code snippet lists the ZIP file entries in another ZIP file. Adapt it to your needs. ZipFile uses ZipInputStream s under the hood.

The code snippet uses Apache Commons IO , in particular 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<? extends ZipEntry> 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"); } 

Answer 2

If you want to recursively view zip files in zip files,

  public void lookupSomethingInZip(InputStream fileInputStream) throws IOException { ZipInputStream zipInputStream = new ZipInputStream(fileInputStream); String entryName = ""; ZipEntry entry = zipInputStream.getNextEntry(); while (entry!=null) { entryName = entry.getName(); if (entryName.endsWith("zip")) { //recur if the entry is a zip file lookupSomethingInZip(zipInputStream); } //do other operation with the entries.. entry=zipInputStream.getNextEntry(); } } 

Call the method with the file input stream received from the file -

 File file = new File(name); lookupSomethingInZip(new FileInputStream(file)); 

Answer 3

I wrote code that can unzip all zip files inside a zip file. It can even decompress up to n compression levels. For example, if you have a zip file inside zip, inside zip (and so on), it will 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<File> current; private static List<File> 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()); } } 

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