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Extracting PDF inside a Zip inside a Zip

i have checked everywhere online and stackoverflow and could not find a match specific to this issue.
I am trying to extract a pdf file that is located in a zip file that is inside a zip file (nested zips).
Re-calling the method i am using to extract does not work nor does changing the whole program to accept Inputstreams instead of how i am doing it below.
The .pdf file inside the nested zip is just skipped at this stage
public static void main(String[] args)
{
try
{
//Paths
String basePath = "C:\\Users\\user\\Desktop\\Scan\\";
File lookupDir = new File(basePath + "Data\\");
String doneFolder = basePath + "DoneUnzipping\\";
File[] directoryListing = lookupDir.listFiles();
for (int i = 0; i < directoryListing.length; i++)
{
if (directoryListing[i].isFile()) //there's definately a file
{
//Save the current file's path
String pathOrigFile = directoryListing[i].getAbsolutePath();
Path origFileDone = Paths.get(pathOrigFile);
Path newFileDone = Paths.get(doneFolder + directoryListing[i].getName());
//unzip it
if(directoryListing[i].getName().toUpperCase().endsWith(ZIP_EXTENSION)) //ZIP files
{
unzip(directoryListing[i].getAbsolutePath(), DESTINATION_DIRECTORY + directoryListing[i].getName());
//move to the 'DoneUnzipping' folder
Files.move(origFileDone, newFileDone);
}
}
}
} catch (Exception e)
{
e.printStackTrace(System.out);
}
}
private static void unzip(String zipFilePath, String destDir)
{
//buffer for read and write data to file
byte[] buffer = new byte[BUFFER_SIZE];
try (ZipInputStream zis = new ZipInputStream(new FileInputStream(zipFilePath)))
{
FileInputStream fis = new FileInputStream(zipFilePath);
ZipEntry ze = zis.getNextEntry();
while(ze != null)
{
String fileName = ze.getName();
int index = fileName.lastIndexOf("/");
String newFileName = fileName.substring(index + 1);
File newFile = new File(destDir + File.separator + newFileName);
//Zips inside zips
if(fileName.toUpperCase().endsWith(ZIP_EXTENSION))
{
ZipInputStream innerZip = new ZipInputStream(zis);
ZipEntry innerEntry = null;
while((innerEntry = innerZip.getNextEntry()) != null)
{
System.out.println("The file: " + fileName);
if(fileName.toUpperCase().endsWith("PDF"))
{
FileOutputStream fos = new FileOutputStream(newFile);
int len;
while ((len = innerZip.read(buffer)) > 0)
{
fos.write(buffer, 0, len);
}
fos.close();
}
}
}
//close this ZipEntry
zis.closeEntry(); // java.io.IOException: Stream Closed
ze = zis.getNextEntry();
}
//close last ZipEntry
zis.close();
fis.close();
} catch (IOException e)
{
e.printStackTrace();
}
}

The solution to this is not as obvious as it seems. Despite writing a few zip utilities myself some time ago, getting zip entries from inside another zip file only seems obvious in retrospect
(and I also got the java.io.IOException: Stream Closed on my first attempt).
The Java classes for ZipFile and ZipInputStream really direct your thinking into using the file system, but it is not required.
The functions below will scan a parent-level zip file, and continue scanning until it finds an entry with a specified name. (Nearly) everything is done in-memory.
Naturally, this can be modified to use different search criteria, find multiple file types, etc. and take different actions, but this at least demonstrates the basic technique in question -- zip files inside of zip files -- no guarantees on other aspects of the code, and someone more savvy could most likely improve the style.
final static String ZIP_EXTENSION = ".zip";
public static byte[] getOnePDF() throws IOException
{
final File source = new File("/path/to/MegaData.zip");
final String nameToFind = "FindThisFile.pdf";
final ByteArrayOutputStream mem = new ByteArrayOutputStream();
try (final ZipInputStream in = new ZipInputStream(new BufferedInputStream(new FileInputStream(source))))
{
digIntoContents(in, nameToFind, mem);
}
// Save to disk, if you want
// copy(new ByteArrayInputStream(mem.toByteArray()), new FileOutputStream(new File("/path/to/output.pdf")));
// Otherwise, just return the binary data
return mem.toByteArray();
}
private static void digIntoContents(final ZipInputStream in, final String nameToFind, final ByteArrayOutputStream mem) throws IOException
{
ZipEntry entry;
while (null != (entry = in.getNextEntry()))
{
final String name = entry.getName();
// Found the file we are looking for
if (name.equals(nameToFind))
{
copy(in, mem);
return;
}
// Found another zip file
if (name.toUpperCase().endsWith(ZIP_EXTENSION.toUpperCase()))
{
digIntoContents(new ZipInputStream(new ByteArrayInputStream(getZipEntryFromMemory(in))), nameToFind, mem);
}
}
}
private static byte[] getZipEntryFromMemory(final ZipInputStream in) throws IOException
{
final ByteArrayOutputStream mem = new ByteArrayOutputStream();
copy(in, mem);
return mem.toByteArray();
}
// General purpose, reusable, utility function
// OK for binary data (bad for non-ASCII text, use Reader/Writer instead)
public static void copy(final InputStream from, final OutputStream to) throws IOException
{
final int bufferSize = 4096;
final byte[] buf = new byte[bufferSize];
int len;
while (0 < (len = from.read(buf)))
{
to.write(buf, 0, len);
}
to.flush();
}

Your question asks how to use java (by implication in windows) to extract a pdf from a zip inside another outer zip.
In many systems including windows it is a single line command that will depend on the location of source and target folders, however using the shortest example of current downloads folder it would be in a shell as simple as
tar -xf "german (2).zip" && tar -xf "german.zip" && german.pdf
to shell the command in windows see
How do I execute Windows commands in Java?
The default pdf viewer can open the result so Windows Edge or in my case SumatraPDF
There is generally no point in putting a pdf inside a zip because it cannot be run in there. So single nesting would be advisable if needed for download transportation.
There is no need to add a password to the zip because PDF uses its own password for opening. Thus unwise to add two levels of complexity. Keep it simple.
If you have multiple zips nested inside multiple zips with multiple pdfs in each then you have to be more specific by filtering names. However avoid that extra onion skin where possible.
\Downloads>tar -xf "german (2).zip" "both.zip" && tar -xf "both.zip" "English language.pdf"
You could complicate that by run in a memory or temp folder but it is reliable and simple to use the native file system so consider without Java its fastest to run
CD /D "C:/Users/user/Desktop/Scan/DoneUnzipping" && for %f in (..\Data\*.zip) do tar -xf "%f" "*.zip" && for %f in (*.zip) do tar -xf "%f" "*.pdf" && del "*.zip"
This will extract all inner zips into working folder then extract all PDFs and remove all the essential temporary zips. The source double zips will not be deleted simply touched.

The line that causes your problem looks to be auto-close block you have created when reading the inner zip:
try(ZipInputStream innerZip = new ZipInputStream(fis)) {
...
}
Several likely issues: firstly it is reading the wrong stream - fis not the existing zis.
Secondly, you shouldn't use try-with-resources for auto-close on innerZip as this implicitly calls innerZip.close() when exiting the block. If you view the source code of ZipInputStream via a good IDE you should see (eventually) that ZipInputStream extends InflaterInputStream which itself extends FilterInputStream. A call to innerZip.close() will close the underlying outer stream zis (fis in your case) hence stream is closed when you resume the next entry of the outer zip.
Therefore remove the try() block and add use of zis:
ZipInputStream innerZip = new ZipInputStream(zis);
Use try-catch block only for the outermost file handling:
try (ZipInputStream zis = new ZipInputStream(new FileInputStream(zipFilePath))) {
ZipEntry ze = zis.getNextEntry();
...
}
Thirdly, you appear to be copying the wrong stream when extracting a PDF - use innerZip not outer zis. The code will never extract PDF as these 2 lines can never be true at the same time because a file ending ZIP will never end PDF too:
if(fileName.toUpperCase().endsWith(ZIP_EXTENSION)) {
...
// You want innerEntry.getName() here
if(fileName.toUpperCase().endsWith("PDF"))
You should be able to switch to one line Files.copy and make use of the PDF filename not zip filename:
if(innerEntry.getName().toUpperCase().endsWith("PDF")) {
Path newFile = Paths.get(destDir + '-'+innerEntry.getName().replace("/", "-"));
System.out.println("Files.copy to " + newFile);
Files.copy(innerZip, newFile);
}

Zipping multiple folders and files in one output using java

So iam working on a project where i get to a point when i need to zip multiple folders (4folders to be specific) and one file in one output.zip file using java
So is there anyway for me to do it and by the way putting all the folders and file in one directory and then zipping it doesn't give the same result in other words the folders have to be in root level of the zip file

There are several solutions.
This one for example:
public static void zipDirectory(ZipOutputStream zos, File fileToZip, String parentDirectoryName) throws Exception
{
if (fileToZip == null || !fileToZip.exists())
{
return;
}
String zipEntryName = fileToZip.getName();
if (parentDirectoryName!=null && !parentDirectoryName.isEmpty())
{
zipEntryName = parentDirectoryName + "/" + fileToZip.getName();
}
// If we are dealing with a directory:
if (fileToZip.isDirectory())
{
System.out.println("+" + zipEntryName);
if(parentDirectoryName == null) // if parentDirectory is null, that means it's the first iteration of the recursion, so we do not include the first container folder
{
zipEntryName = "";
}
for (File file : fileToZip.listFiles()) // we iterate over all the folders/files and archive them by keeping the structure too.
{
zipDirectory(zos, file, zipEntryName);
}
} else // If we are dealing with a file, then we zip it directly
{
System.out.println(" " + zipEntryName);
byte[] buffer = new byte[1024];
FileInputStream fis = new FileInputStream(fileToZip);
zos.putNextEntry(new ZipEntry(zipEntryName));
int length;
while ((length = fis.read(buffer)) > 0)
{
zos.write(buffer, 0, length);
}
zos.closeEntry();
fis.close();
}
}
then you could use this function like this:
try
{
File directoryToBeZipped = new File("C:\\New\\test");
FileOutputStream fos = new FileOutputStream("C:\\New\\test\\archive.zip");
ZipOutputStream zos = new ZipOutputStream(fos);
zipDirectory(zos, directoryToBeZipped, null);
zos.flush();
fos.flush();
zos.close();
fos.close();
} catch (Exception e)
{
e.printStackTrace();
}
Or you could use the ZeroTurnAround ZIP Library. And do this in one line:
ZipUtil.pack(new File("D:\\sourceFolder\\"), new File("D:\\generatedZipFile.zip"));

Dead easy way (though you'll get warnings about proprietary classes)
final String[] ARGS = { "-cfM", "x.zip", "folder1", "folder2", "folder3", "folder4", "file.txt" };
sun.tools.jar.Main.main(ARGS);
It might be worth getting a similar thing that won't give you warnings

Cannot delete zip file after unzipping?

I am facing an unusal issue.I am building a tool which is scheduled to run every 5 mins.
It will pick up the zip files from a particular directory and extract files (depending on the file name) to a destination. I am using zipentry to get each filename in zip file and then extracting as required then I back them (zip files, once I finish all the files in a zip) to a particular directory and then delete the zip file. But sometimes (not always) the zip files do not get deleted. Since I am using fileutils.forcedelete(). I am getting an exception: unable to delete file. So I changed to the code to using fileutils.forcedeleteonexit() still some files remain in the source.
Here is a sample of my code:
sourceFile=new file(zipfile);
zipFile = new ZipFile(sourceFile);
zEnum = (Enumeration<ZipEntry>) zipFile.entries();
for (int a = 0; a < zipFile.size(); a++)
{
ZipEntry zE = zEnum.nextElement();
//Function uses zip4j for extracting. No streams used.
extract(String sourceZipFile, String fileNameToExtract, String outputFolder);
}
//I tried it with finally either
zipFile.close();
//Using fileutils to copy. No streams used.
copyFile(sourceFile, backup);
FileUtils.forceDeleteOnExit(sourceFile);
There are no streams used but I am getting a lock on files sometimes (not always).
What seems to be the bug here? Is it the zip4j extraction that is causing the problem or anything else? I am using zip4j 1.3.1.

I think your problem related with OS file buffers, that sometimes are not flushed when you are trying to delete file.
Did you try to use sourceFile.deleteOnExit() instead FileUtils.forceDeleteOnExit(sourceFile)?
Also you can try to check sourceFile.canWrite before deleting (may be it may helps)
You can also try to use FileInputStream() before deleting:
FileInputStream fi = new FileInputStream(sourceFile);
fi.getFD().sync();

Use apache-commons IO's FileDeleteStrategy. Something like:
FileDeleteStrategy.FORCE.delete(file);
Update:
It should be the way IO is being handled in your application. I have written simple code which copies a zip file to a temporary zip, deflates the temporary zip and after few seconds deletes it. Here you go:
public class ZipTest {
private static String dirPath = "/home/ubuntuuser/Desktop/";
public static void main(String[] args) throws Exception {
File myzip = new File(dirPath + "content.zip");
String tempFileStr = dirPath + "content_temp.zip";
File tempFile = new File(tempFileStr);
String unzipFolderStr = dirPath + "unzip";
copyUsingChannels(myzip, tempFile);
// copyUsingStreams(myzip, tempFile);
unZip(tempFileStr, unzipFolderStr);
Thread.sleep(3000);
tempFile.delete();
}
private static void copyUsingStreams(File myzip, File tempFile)
throws IOException, FileNotFoundException {
byte[] barray = new byte[1024];
if (!tempFile.exists())
{
tempFile.createNewFile();
}
FileOutputStream fos = new FileOutputStream(tempFile);
FileInputStream fis = new FileInputStream(myzip);
int length = 0;
while ((length = fis.read(barray)) != -1)
{
fos.write(barray, 0, length);
}
fis.close();
fos.close();
}
public static void copyUsingChannels(final File srcFile, final File destFile) throws Exception
{
if (!destFile.exists())
{
destFile.createNewFile();
}
FileChannel source = new FileInputStream(srcFile).getChannel();
FileChannel destination = new FileOutputStream(destFile).getChannel();
source.transferTo(0, source.size(), destination);
source.close();
destination.close();
}
private static void unZip(String zipFile, String outputFolder) throws Exception {
byte[] buffer = new byte[1024];
File folder = new File(outputFolder);
if (!folder.exists()) {
folder.mkdir();
}
ZipInputStream zis = new ZipInputStream(new FileInputStream(zipFile));
ZipEntry ze = zis.getNextEntry();
while (ze != null) {
String fileName = ze.getName();
File newFile = new File(outputFolder + File.separator + fileName);
System.out.println("file unzip : " + newFile.getAbsoluteFile());
new File(newFile.getParent()).mkdirs();
if (ze.isDirectory())
{
newFile.mkdir();
ze = zis.getNextEntry();
continue;
}
FileOutputStream fos = new FileOutputStream(newFile);
int len;
while ((len = zis.read(buffer)) > 0) {
fos.write(buffer, 0, len);
}
fos.close();
ze = zis.getNextEntry();
}
zis.closeEntry();
zis.close();
}
}

How to decompress a zip archive which has sub directories?

Say I have a zip file MyZipFile.zip which contains (1) a file MyFile.txt and (2) a folder MyFolder which contains a file MyFileInMyFolder.txt, i.e. something as follows:
MyZipFile.zip
|-> MyFile.txt
|-> MyFolder
|-> MyFileInMyFolder.txt
I want to decompress this zip archive. The most common code sample I have been able to find searching online uses the ZipInputStream class somewhat like the code pasted at the bottom of this question. The problem with this however, using the example above, is that it will create MyFolder but will not decompress the contents of MyFolder. Anyone know whether it is possible to decompress the contents of a folder in a zip archive using ZipInputStream or by any other means?
public static boolean unzip(File sourceZipFile, File targetFolder)
{
// pre-stuff
ZipInputStream zipInputStream = new ZipInputStream(new FileInputStream(sourceZipFile));
ZipEntry zipEntry = null;
while ((zipEntry = zipInputStream.getNextEntry()) != null)
{
File zipEntryFile = new File(targetFolder, zipEntry.getName());
if (zipEntry.isDirectory())
{
if (!zipEntryFile.exists() && !zipEntryFile.mkdirs())
return false;
}
else
{
FileOutputStream fileOutputStream = new FileOutputStream(zipEntryFile);
byte buffer[] = new byte[1024];
int count;
while ((count = zipInputStream.read(buffer, 0, buffer.length)) != -1)
fileOutputStream.write(buffer, 0, count);
fileOutputStream.flush();
fileOutputStream.close();
zipInputStream.closeEntry();
}
}
zipInputStream.close();
// post-stuff
}

Try this:
ZipInputStream zis = null;
try {
zis = new ZipInputStream(new FileInputStream(zipFilePath));
ZipEntry entry;
while ((entry = zis.getNextEntry()) != null) {
// Create a file on HDD in the destinationPath directory
// destinationPath is a "root" folder, where you want to extract your ZIP file
File entryFile = new File(destinationPath, entry.getName());
if (entry.isDirectory()) {
if (entryFile.exists()) {
logger.log(Level.WARNING, "Directory {0} already exists!", entryFile);
} else {
entryFile.mkdirs();
}
} else {
// Make sure all folders exists (they should, but the safer, the better ;-))
if (entryFile.getParentFile() != null && !entryFile.getParentFile().exists()) {
entryFile.getParentFile().mkdirs();
}
// Create file on disk...
if (!entryFile.exists()) {
entryFile.createNewFile();
}
// and rewrite data from stream
OutputStream os = null;
try {
os = new FileOutputStream(entryFile);
IOUtils.copy(zis, os);
} finally {
IOUtils.closeQuietly(os);
}
}
}
} finally {
IOUtils.closeQuietly(zis);
}
Note, that it uses Apache Commons IO to handle stream copying / closing.

How to zip only .txt file in a folder using java?

here i'm trying to zip only .txt file in a folder using java.
My code here was found with google and works perfectly but only for a specified .txt file.
Thank you.
import java.util.*;
import java.util.zip.*;
import java.io.*;
public class ZipFile
{
public static void main(String[] args) {
ZipOutputStream out = null;
InputStream in = null;
try {
File inputFile1 = new File("c:\\Target\\target.txt");// here i want to say only the directroy where .txt files are stored
File outputFile = new File("c:\\Target\\Archive_target.zip");//here i want to put zipped file in a different directory
OutputStream rawOut = new BufferedOutputStream(new FileOutputStream(outputFile));
out = new ZipOutputStream(rawOut);
InputStream rawIn = new FileInputStream(inputFile1);
in = new BufferedInputStream(rawIn);
ZipEntry entry = new ZipEntry("c:\\Target\\target.txt");
out.putNextEntry(entry);
byte[] buf = new byte[2048];
int len;
while ((len = in.read(buf)) > 0) {
out.write(buf, 0, len);
}
}
catch(IOException e) {
e.printStackTrace();
}
finally {
try {
if(in != null) {
in.close();
}
if(out != null) {
out.close();
}
}
catch(IOException ignored)
{ }
}
}
}

You need to use File.list(...) to get a list of all the text files in the folder. Then you create a loop to write each file to the zip file.

I just add these lines just after
"File outputFile = new File("c:\Target\Archive_target.zip");
from my previous code.
code added:
File Dir = new File("c:/Target");
FilenameFilter filter = new FilenameFilter() {
public boolean accept(File dir, String name) {
return !name.startsWith(".txt");
}
};
String[] children = Dir.list(filter);

You can get a list of all text files in your directory by using the following method of the File class:
String[] list(FilenameFilter filter)
Create a File object that points to your DIRECTORY (I know it sounds illogical, but that's the way it is- you can test if it is a directory using isDirectory()) and then use the FilenameFilter to say, for example, accept this file if its name contain ".txt"

Create a FilenameFilter that accepts only *.txt file , and then just use
list = File.list(yourNameFilter);
and then just add all the files in the list to the zip file