javazipunzipfileinputstreamzipinputstream

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();
        }
        
    }

Solution

  • So I found no way to do as my question states, and no one answered with the below (so sorry for answering my own question posted). The problem comes in when reading the path of the zip inside the zip. What needs to happen, and what is illustrated below, is the nested zip needs to be moved to a temp folder and extracted there and removed afterwards. So the unzip function is called as many times as there are nested zips.

    I struggled a while with this one, hope it helps someone somewhere along the line..

    import java.util.logging.Logger;
    import java.util.logging.FileHandler;
    import java.util.logging.SimpleFormatter;
    import java.util.zip.ZipInputStream;
    import java.io.FileInputStream;
    import java.io.IOException;
    import java.nio.file.Files;
    import java.nio.file.Path;
    import java.nio.file.Paths;
    import java.io.File;
    import java.io.FileOutputStream;
    import java.util.zip.ZipEntry;
    import java.io.BufferedWriter;
    import java.io.FileWriter;
    import java.io.PrintWriter;
    
    public class Unzipper
    {   
        private static  String baseDir = "";
        private static  String PDF_DESTINATION_DIRECTORY = "";
        private static  String extractionLogFile = "";
    
    private static final int BUFFER_SIZE = 4096;
    private static int count = 0;
    private static int loggedCount = 0;
    private static String ZIP_EXTENSION = "ZIP";
    
    public static void main(String[] args)
    {
    
        baseDir = File.separator + "Users" + File.separator + "user" + File.separator + "Desktop" + File.separator + "ZipFolder" + File.separator;
        PDF_DESTINATION_DIRECTORY = File.separator +"Users" + File.separator + "user" + File.separator +"Desktop" + File.separator + "ZipFolder" + File.separator + "PDFs" + File.separator;
        extractionLogFile = File.separator + "Users" + File.separator + "user" + File.separator +"Desktop" + File.separator + "ZipFolder" + File.separator + "ExtractionLogFile.txt";       
        
    
        try
        {
            //Paths
            File lookupDir = new File(baseDir);
            String doneFolder = PDF_DESTINATION_DIRECTORY;
    
            //Logger properties
            Logger logger = Logger.getLogger("ExtractionLog");
            FileHandler fh;
            fh = new FileHandler(extractionLogFile);
            logger.addHandler(fh);
            logger.setUseParentHandlers(false);
            SimpleFormatter formatter = new SimpleFormatter();
            fh.setFormatter(formatter);
    
            //make some folders if they are not there
            makeDirIfNotExist(baseDir + "PDFs");
            makeDirIfNotExist(baseDir + File.separator + "_Temp");
    
            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());
    
                    //make sure directory exist
                    String dirPDFdestName = directoryListing[i].getName();
                    makeDirIfNotExist(PDF_DESTINATION_DIRECTORY.concat(dirPDFdestName.substring(0, dirPDFdestName.length() - 4)));
    
                    //unzip it
                    if (directoryListing[i].getName().toUpperCase().endsWith(ZIP_EXTENSION)) //ZIP files
                    {
                        checkTheZip(directoryListing[i].getAbsolutePath(), PDF_DESTINATION_DIRECTORY.concat(dirPDFdestName.substring(0, dirPDFdestName.length() - 4)));
                        //move to the 'PDFs' folder
                        moveFile(origFileDone, newFileDone);
                    }
                }
            }
    
            logger.info("Cycle completed, Processed files: " + loggedCount); // (just checking)
            loggedCount = 0;
        } catch (Exception e)
        {
            appendToFile(e);
        }
    }
    
    //dig into the zip file
    private static void checkTheZip(String zipFilePath, String destDirName)
    {
        unzip(zipFilePath, destDirName);
        loggedCount++;
    }
    
    //move the file
    private static void moveFile(Path fromDest, Path toDest)
    {
        File lookupDir = new File(toDest.toString());
        try
        {
            if(!lookupDir.exists())
            {
                Files.move(fromDest, toDest); //, OPTIONAL: StandardCopyOption.REPLACE_EXISTING
            }
        } catch (Exception e)
        {        
            appendToFile(e);
        }
    }
    
    private static File makeDirIfNotExist(String directory)
    {
        File dir = new File(directory);
        if (!dir.exists())
        {
            dir.mkdir();
        }
        return new File(directory + File.separator);
    }
    
    
       public static void appendToFile(Exception e) 
       {
          try 
          {
             FileWriter fstream = new FileWriter(extractionLogFile, true);
             BufferedWriter out = new BufferedWriter(fstream);
             PrintWriter pWriter = new PrintWriter(out, true);
             e.printStackTrace(pWriter);
          }
          catch (Exception ie) 
          {
             throw new RuntimeException("Could not write Exception to file", ie);
          }
       }
    
    private static void unzip(String zipFilePath, String destDirName)
    {
        //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(File.separator);
                String newFileName = fileName.substring(index + 1);
                File newFile = new File(destDirName + File.separator + newFileName);
    
                //PDFs
                if (fileName.toUpperCase().endsWith("PDF"))
                {
                    FileOutputStream fos = new FileOutputStream(newFile);
                    int len;
                    while ((len = zis.read(buffer)) > 0)
                    {
                        fos.write(buffer, 0, len);
                    }
                    fos.close();
    
                }
    
                //Zips inside zips  
                if (fileName.toUpperCase().endsWith(ZIP_EXTENSION))
                {
                    Path newFileDone = Paths.get(baseDir + "_Temp");
                    Path origFileDone = Paths.get(destDirName + File.separator);
                    newFile = new File(baseDir + "_Temp" + File.separator + newFileName);
                    
                    FileOutputStream fos = new FileOutputStream(newFile);
                    int len;
                    while ((len = zis.read(buffer)) > 0)
                    {
                        fos.write(buffer, 0, len);
                    }
                    fos.close();
    
                    //move the zip out of the folder to a temp folder then
                    moveFile(origFileDone, newFileDone);
                    
                    //search the temp folder for entries and handle the .zip file from there
                    checkTheZip(baseDir + "_Temp" + File.separator + fileName, destDirName);
                    
                    //remove the Temp_ folders contents
                    Files.walk(Paths.get(baseDir + "_Temp" + File.separator))
                            .filter(Files::isRegularFile)
                            .map(Path::toFile)
                            .forEach(File::delete);
    
                }
    
                //close this ZipEntry
                zis.closeEntry();
                ze = zis.getNextEntry();
            }
    
            //close last ZipEntry
            zis.close();
            fis.close();
        } catch (IOException e)
        {
            appendToFile(e);
        }
    
       }
    }