Utility to unzip an entire archive to a directory in java

Question

I'd like to do something like this in my program:

File zipFile = .....;
File destDir = ....;    
ImaginaryZipUtility.unzipAllTo(zipFile, destdir);

I cannot possibly be the first to do this from a program. Where do I find a utility method like above? I tried to look at apache commons-io, but nothing there. So, where should I look?

Answer 1

Very old code that I was able to dig up

package com.den.frontend;

import java.util.*;
import java.util.zip.*;
import java.io.*;

public class ZIPUtility 
    {
        public static final int BUFFER_SIZE = 2048;

        //This function converts the zip file into uncompressed files which are placed in the 
        //destination directory
        //destination directory should be created first
        public static boolean unzipFiles(String srcDirectory, String srcFile, String destDirectory)
        {
            try
            {
                //first make sure that all the arguments are valid and not null
                if(srcDirectory == null)
                {
                    System.out.println(1);
                    return false;
                }
                if(srcFile == null)
                {
                    System.out.println(2);
                    return false;
                }
                if(destDirectory == null)
                {
                    System.out.println(3);
                    return false;
                }
                if(srcDirectory.equals(""))
                {
                    System.out.println(4);
                    return false;
                }
                if(srcFile.equals(""))
                {   
                    System.out.println(5);
                    return false;
                }
                if(destDirectory.equals(""))
                {
                    System.out.println(6);
                    return false;
                }
                //now make sure that these directories exist
                File sourceDirectory = new File(srcDirectory);
                File sourceFile = new File(srcDirectory + File.separator + srcFile);
                File destinationDirectory = new File(destDirectory);

                // Prevent "Zip Slip" vulnerability https://snyk.io/research/zip-slip-vulnerability
                String canonicalDestinationFile = sourceFile.getCanonicalPath();
                if (!canonicalDestinationFile.startsWith(destinationDirectory.getCanonicalPath() + File.separator)) {
                    throw new Exception("Entry is outside of the target dir: " + e.getName());
                }

                if(!sourceDirectory.exists())
                {
                    System.out.println(7);
                    return false;
                }
                if(!sourceFile.exists())
                {
                    System.out.println(sourceFile);
                    return false;
                }
                if(!destinationDirectory.exists())
                {
                    System.out.println(9);
                    return false;
                }

                //now start with unzip process
                BufferedOutputStream dest = null;

                FileInputStream fis = new FileInputStream(sourceFile);
                ZipInputStream zis = new ZipInputStream(new BufferedInputStream(fis));

                ZipEntry entry = null;

                while((entry = zis.getNextEntry()) != null)
                {
                    String outputFilename = destDirectory + File.separator + entry.getName();

                    System.out.println("Extracting file: " + entry.getName());

                    createDirIfNeeded(destDirectory, entry);

                    int count;

                    byte data[] = new byte[BUFFER_SIZE];

                    //write the file to the disk
                    FileOutputStream fos = new FileOutputStream(outputFilename);
                    dest = new BufferedOutputStream(fos, BUFFER_SIZE);

                    while((count = zis.read(data, 0, BUFFER_SIZE)) != -1)
                    {
                        dest.write(data, 0, count);
                    }

                    //close the output streams
                    dest.flush();
                    dest.close();
                }

                //we are done with all the files
                //close the zip file
                zis.close();

            }
            catch(Exception e)
            {
                e.printStackTrace();
                return false;
            }

            return true;
        }

        private static void createDirIfNeeded(String destDirectory, ZipEntry entry)
        {
            String name = entry.getName();

            if(name.contains("/"))
            {
                System.out.println("directory will need to be created");

                int index = name.lastIndexOf("/");
                String dirSequence = name.substring(0, index);

                File newDirs = new File(destDirectory + File.separator + dirSequence);

                //create the directory
                newDirs.mkdirs();
            }
        }

    }

Answer 2

I know I'm, pretty late to the show, but I was looking for the same thing and found this via google. The easiest way I found is the ant task "unzip". You can use it without any complicated ant setup (there is stuff like ProjectHelper to build a complete ant project) from your java source by including

<dependency>
    <groupId>org.apache.ant</groupId>
    <artifactId>ant-compress</artifactId>
    <version>1.2</version>
</dependency>

The code to unzip a file to a directory looks like this

org.apache.ant.compress.taskdefs.Unzip u = new Unzip();
u.setSrc(new File("<archive.zip>"));
u.setDest(new File("<targetDir>"));
u.execute();