Reputation: 57

unzip file by using java

public void unZipFile(String zipFileLocation, String outputFolder) {
    logger.info("ZipFileLocation: "+zipFileLocation);
    logger.info("OutputLocation: "+outputFolder);

    File dir = new File(outputFolder);
    // create output directory if it doesn't exist
    if(!dir.exists()) dir.mkdirs();
    FileInputStream fis;
    //buffer for read and write data to file
    byte[] buffer = new byte[1024];
    try {
        fis = new FileInputStream(zipFileLocation);
        ZipInputStream zis = new ZipInputStream(fis);
        ZipEntry ze = zis.getNextEntry();
        while(ze != null){
            String fileName = ze.getName();
            File newFile = new File(outputFolder + File.separator + fileName);
            System.out.println("Unzipping to "+newFile.getAbsolutePath());
            //create directories for sub directories in zip
            new File(newFile.getParent()).mkdirs();
            FileOutputStream fos = new FileOutputStream(newFile);
            int len;
            while ((len = zis.read(buffer)) > 0) {
                fos.write(buffer, 0, len);
            }
            fos.close();
            //close this ZipEntry
            zis.closeEntry();
            ze = zis.getNextEntry();
        }
        //close last ZipEntry
        zis.closeEntry();
        zis.close();
        fis.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

This is a code that i have used to unzip folder to specific location. i am getting following exception once i execute this process. please advice why this issue arise?

 java.util.zip.ZipException: invalid entry size (expected 3173388 but got 3173359 bytes)
 [java]     at java.util.zip.ZipInputStream.readEnd(ZipInputStream.java:403)
 [java]     at java.util.zip.ZipInputStream.read(ZipInputStream.java:195)
 [java]     at java.io.FilterInputStream.read(FilterInputStream.java:107)
 [java]     at com.shipxpress.irf.server.service.impl.IrfServiceImpl.unZipFile(IrfServiceImpl.java:1020)
 [java]     at com.shipxpress.irf.server.service.impl.IrfServiceImpl.executeFileTransferProcess(IrfServiceImpl.java:1310)
 [java]     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 [java]     at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
 [java]     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
 [java]     at java.lang.reflect.Method.invoke(Method.java:606)

Really appreciate if anyone can help me to fix this issue

Thanks,

Upvotes: 0

Answers (5)

amralieg

Reputation: 123

I had similar problem, and I modifed the code to work, it turn out the code does not distinguish between a file and a folder and that's that check that I added.

    public static void unzipFile(String zipFilePath, String destDir)
    {
        File dir = new File(destDir);
        // create output directory if it doesn't exist
        if (!dir.exists())
            dir.mkdirs();
        FileInputStream fis;
        // buffer for read and write data to file
        byte[] buffer = new byte[1024];
        try
        {
            fis = new FileInputStream(zipFilePath);
            ZipInputStream zis = new ZipInputStream(fis);
            ZipEntry ze = zis.getNextEntry();
            while (ze != null)
            {
                try
                {
                    String fileName = ze.getName();
                    File newFile = new File(destDir + File.separator + fileName);
                    System.out.println("Unzipping to " + newFile.getAbsolutePath());
                    // create directories for sub directories in zip
                    new File(newFile.getParent()).mkdirs();
                    if(ze.isDirectory()) // check if this is a diectory or file
                    {
                        newFile.mkdirs();
                    }
                    else
                    {
                        FileOutputStream fos = new FileOutputStream(newFile);
                        int len;
                        while ((len = zis.read(buffer)) > 0)
                        {
                            fos.write(buffer, 0, len);
                        }
                        fos.close();
                    }
                    // close this ZipEntry
                    zis.closeEntry();
                }
                catch(Exception e)
                {
                    System.err.println(e.getMessage());
                }
                ze = zis.getNextEntry();
            }
            // close last ZipEntry
            zis.closeEntry();
            zis.close();
            fis.close();
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
    }

Upvotes: 0

Varun A M

Reputation: 1162

Instead of hard-coding it as

byte[] buffer = new byte[1024];

Try below.

byte[] buffer = new byte[(int) ze.getSize()];

You can find the detailed tutorial here.

https://www.youtube.com/watch?v=hzBlCnkhKog

Upvotes: 0

KuLdip PaTel

Reputation: 1069

Use this library www.lingala.net/zip4j/

add this jar file in lib folder of app.

check your import like that

import net.lingala.zip4j.core.ZipFile;

import net.lingala.zip4j.exception.ZipException;

import net.lingala.zip4j.model.FileHeader;

use below method like this

unzip("/sdcard/file.zip","/sdcard/unzipFolder")


  public static void unzip(String Filepath, String DestinationFolderPath) {

        try {
            ZipFile zipFile = new ZipFile(Filepath);
            List fileHeaders = zipFile.getFileHeaders();
            for(int i=0;i<fileHeaders.size();i++) {
                FileHeader  fileHeader=(FileHeader) fileHeaders.get(i);
                String fileName = fileHeader.getFileName();
                Log.d(TAG,fileName);
                if (fileName.contains("\\")) {
                    fileName=fileName.replace("\\","\\\\");
                    String[] Folders=fileName.split("\\\\");
                    StringBuilder newFilepath=new StringBuilder();
                    newFilepath.append(DestinationFolderPath);
                    for (int j=0;j<Folders.length-1;j++){
                        newFilepath.append(File.separator);
                        newFilepath.append(Folders[j]);
                    }
                    zipFile.extractFile(fileHeader, newFilepath.toString(),null,Folders[Folders.length-1]);
                }else {
                    zipFile.extractFile(fileHeader,DestinationFolderPath);
                }
            }
        } catch (ZipException e) {
            e.printStackTrace();
        }
    }

Upvotes: 1

P S M

Reputation: 1161

I could think of these reasons:

The file could simply be corrupt.Try opening the file with a zip utility.
There could be a problem with the encoding of the text file.
The file needs to be read/transferred in "binary" mode.
There could be an issue with the line ending \n or \r\n

Upvotes: 0

Jerome L

Reputation: 637

I don't exactly know why it fails in your case (invalid zip file?), but I would recommend:

First, use Java 7 java.nio.file.Path API which is far better than the old java.io.File.
Second, It's way more convenient to use Apache Commons Compress when dealing with compressed files. It's way more flexible as it can handle zip, bzip, 7zip, pack200 and more formats,
Last, perform .close() operations in a try ... finally block to avoid unclosed streams in case of exception.

Upvotes: 0

unzip file by using java

Answers (5)

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