How to unzip files recursively in Java?

Question

I have zip file which contains some other zip files.

For example, the mail file is abc.zip and it contains xyz.zip, class1.java

Answer 1

Here is some code, which I tested to be working quite well :

package com.test;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.util.Enumeration;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;

public class Unzipper {  
    private final static int BUFFER_SIZE = 2048;
    private final static String ZIP_FILE = "/home/anton/test/test.zip";
    private final static String DESTINATION_DIRECTORY = "/home/anton/test/";
    private final static String ZIP_EXTENSION = ".zip";
 
    public static void main(String[] args) {
     System.out.println("Trying to unzip file " + ZIP_FILE); 
        Unzipper unzip = new Unzipper();  
        if (unzip.unzipToFile(ZIP_FILE, DESTINATION_DIRECTORY)) {
         System.out.println("Succefully unzipped to the directory " 
             + DESTINATION_DIRECTORY);
        } else {
         System.out.println("There was some error during extracting archive to the directory " 
             + DESTINATION_DIRECTORY);
        }
    } 

 public boolean unzipToFile(String srcZipFileName,
   String destDirectoryName) {
  try {
   BufferedInputStream bufIS = null;
   // create the destination directory structure (if needed)
   File destDirectory = new File(destDirectoryName);
   destDirectory.mkdirs();

   // open archive for reading
   File file = new File(srcZipFileName);
   ZipFile zipFile = new ZipFile(file, ZipFile.OPEN_READ);

   //for every zip archive entry do
   Enumeration zipFileEntries = zipFile.entries();
   while (zipFileEntries.hasMoreElements()) {
    ZipEntry entry = (ZipEntry) zipFileEntries.nextElement();
    System.out.println("\tExtracting entry: " + entry);

    //create destination file
    File destFile = new File(destDirectory, entry.getName());

    //create parent directories if needed
    File parentDestFile = destFile.getParentFile();    
    parentDestFile.mkdirs();    
    
    if (!entry.isDirectory()) {
     bufIS = new BufferedInputStream(
       zipFile.getInputStream(entry));
     int currentByte;

     // buffer for writing file
     byte data[] = new byte[BUFFER_SIZE];

     // write the current file to disk
     FileOutputStream fOS = new FileOutputStream(destFile);
     BufferedOutputStream bufOS = new BufferedOutputStream(fOS, BUFFER_SIZE);

     while ((currentByte = bufIS.read(data, 0, BUFFER_SIZE)) != -1) {
      bufOS.write(data, 0, currentByte);
     }

     // close BufferedOutputStream
     bufOS.flush();
     bufOS.close();

     // recursively unzip files
     if (entry.getName().toLowerCase().endsWith(ZIP_EXTENSION)) {
      String zipFilePath = destDirectory.getPath() + File.separatorChar + entry.getName();

      unzipToFile(zipFilePath, zipFilePath.substring(0, 
              zipFilePath.length() - ZIP_EXTENSION.length()));
     }
    }
   }
   bufIS.close();
   return true;
  } catch (Exception e) {
   e.printStackTrace();
   return false;
  }
 } 
}  

I tried with the top voted answer here, and that does not recursively unzip the files, it just unzips the files of the first level.

Source : Solution which extracts files into a given directory

Also, check this solution by the same person : Solution which extracts file in memory