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Java - Getting specific folder and files from zip file

So I am working on an Android app and what I am trying to do is make it so a user selects a zip file, it extracts the contents of it into an apk and installs the modified APK for the user. Right now all the files in the zip file have to be in the root of the zip file for it to work, if there is a directory and than the files I need it will not work. I am trying to make it scan for, for example the 'assets' folder and than get the directory its located in and copy all the files from that directory. I've tried extracting the files first and scanning using a loop, and for some reason had no success doing that, and it was time consuming anyways. If you know any libraries or could point me in the right direction that would be great! Thanks!

BTW you can extract all the files from zip folder like below. i.e
private String unpackZip(String path, String zipname) {
String apkfilename = "";
InputStream is;
ZipInputStream zis;
try {
String filename;
is = new FileInputStream(path + "/" + zipname);
zis = new ZipInputStream(new BufferedInputStream(is));
ZipEntry ze;
byte[] buffer = new byte[1024];
int count;
while ((ze = zis.getNextEntry()) != null) {
filename = ze.getName();
// Need to create directories if not exists, or
// it will generate an Exception...
if (ze.isDirectory()) {
File fmd = new File(path + "/" + filename);
fmd.mkdirs();
continue;
}
// This condition is to only extract the apk file
if (filename.endsWith(".apk")) {
apkfilename = filename;
FileOutputStream fout = new FileOutputStream(path + "/"
+ filename);
while ((count = zis.read(buffer)) != -1) {
fout.write(buffer, 0, count);
}
fout.close();
zis.closeEntry();
}
}
zis.close();
} catch (IOException e) {
e.printStackTrace();
return apkfilename;
}
return apkfilename;
}
//To install the apk file call the method
String apkfilename=unpackZip(Environment.getExternalStorageDirectory()
.getPath(), "temp.zip");
try {
File file = new File(Environment.getExternalStorageDirectory()
.getPath(), apkfilename);
Intent promptInstall = new Intent(Intent.ACTION_VIEW).setDataAndType(
Uri.fromFile(file), "application/vnd.android.package-archive");
startActivity(promptInstall);
} catch (Exception e) {
e.printStackTrace();
}
//Also add the read write permission
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

Java Unzip - no Exception but result is empty

i'm using the following code from the web
File dir = new File(dest.getAbsolutePath(), archiveName);
// create output directory if it doesn't exist
if (!dir.exists()) {
dir.mkdirs();
}
System.err.println(pArchivePath);
ZipFile zipFile = null;
try {
zipFile = new ZipFile(pArchivePath);
Enumeration<?> enu = zipFile.entries();
while (enu.hasMoreElements()) {
ZipEntry zipEntry = (ZipEntry) enu.nextElement();
String name = zipEntry.getName();
long size = zipEntry.getSize();
long compressedSize = zipEntry.getCompressedSize();
System.out.printf("name: %-20s | size: %6d | compressed size: %6d\n",
name, size, compressedSize);
File file = new File(name);
if (name.endsWith("/")) {
System.err.println("make dir " + name);
file.mkdirs();
continue;
}
File parent = file.getParentFile();
if (parent != null) {
parent.mkdirs();
}
InputStream is = zipFile.getInputStream(zipEntry);
FileOutputStream fos = new FileOutputStream(file);
byte[] bytes = new byte[1024];
int length;
while ((length = is.read(bytes)) >= 0) {
fos.write(bytes, 0, length);
}
is.close();
fos.close();
}
zipFile.close();
} catch (Exception e) {
e.printStackTrace();
} finally {
if (zipFile != null) {
try {
zipFile.close();
}
catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
to unzip an archive. It's packed with 7zip or Winrar as an .zip archive but renamed to .qtz (but i don't thing this causes the problem..)
So if i run the code to unzip my archive everything works fine: i get the output on sysout/err listing all files and also no exception occurs, but if i look in the destination directory ... it's empty - just the root folder exists.
I also used
Runtime.getRuntime().exec(String.format("unzip %s -d %s", pArchivePath, dest.getPath()));
but I can't use this anymore 'cause a new process is started and I'm continuing working on the archive right after the unzip process in the java code.
Well the question is.. why doesn't this peace of code work? There a lot of similar examples but none of them worked for me.
br, Philipp
EDIT: The following solved my Problem
File file = new File(dir.getParent(), name);
So i didn't set the right parent path for this file.

The below fragment in your code:
File parent = file.getParentFile();
if (parent != null) {
parent.mkdirs();
}
where does this create the parent directories? Because I tried your code and it's not creating in the destination directory but rather in my Eclipse's project directory. Looking at your code, the destination directory is nowhere used, right?
The code actually extracts the contents of the zip file but not where I expected it.

I am thinking because I don't see you doing something like this:
ZipOutputStream out = new ZipOutputStream(new FileOutputStream(zipPath+ "Zip.zip"));
out.putNextEntry(new ZipEntry("Results.csv"));
I am still working on it but I think that the problem because that makes the file inside of the zip
Also you should probably use the ZipOutputStream to write; like
out.write(bytes, 0, length);

How to unzip a Zip file which contains Images without dropping any image in android? [closed]

Closed. This question needs debugging details. It is not currently accepting answers.
Edit the question to include desired behavior, a specific problem or error, and the shortest code necessary to reproduce the problem. This will help others answer the question.
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I am working on unzip the zip file which contains Images only here below my code is given.
public void unZipImages(String zipFile, String outputFolder) {
byte[] buffer = new byte[2048];
try {
// create output directory is not exists
File folder = new File(Environment.getExternalStorageDirectory()
+ "/final_unzip_data/" + AppConstants.ManufacturerCode
+ "/Catalog/" + ""); if (!folder.exists()) {
folder.mkdir(); }
// get the zip file content
ZipInputStream zis = new ZipInputStream(
new FileInputStream(zipFile)); // get the zipped file list entry ZipEntry ze = zis.getNextEntry();
while (ze != null) {
String fileName = ze.getName();
if (fileName.contains("\\")) {
fileName = fileName.replace("\\", "/");
}
File newFile = new File(outputFolder + File.separator
+ fileName);
System.out.println("file unzip : " + newFile.getAbsoluteFile());
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();
ze = zis.getNextEntry(); }
zis.closeEntry(); zis.close();
System.out.println("Done");
} catch (IOException ex) { ex.printStackTrace(); } }
But I don't know what the error is occurring to unzip the file some images are dropping. I have searched many types of codes for unzip but nothing worked.

This code has solved my problem
private void unzipImage(String zipFile, String extractFolder) {
try {
CreateDir();
int BUFFER = 4096;
File file = new File(zipFile);
ZipFile zip = new ZipFile(file);
String newPath = extractFolder;
new File(newPath).mkdir();
Enumeration zipFileEntries = zip.entries();
// Process each entry
while (zipFileEntries.hasMoreElements()) {
// grab a zip file entry
ZipEntry entry = (ZipEntry) zipFileEntries.nextElement();
String currentEntry = entry.getName();
currentEntry = currentEntry.replace('\\', '/');
File destFile = new File(newPath, currentEntry);
// destFile = new File(newPath, destFile.getName());
File destinationParent = destFile.getParentFile();
// create the parent directory structure if needed
destinationParent.mkdirs();
if (!entry.isDirectory()) {
BufferedInputStream is = new BufferedInputStream(
zip.getInputStream(entry));
int currentByte;
// establish buffer for writing file
byte data[] = new byte[BUFFER];
// write the current file to disk
FileOutputStream fos = new FileOutputStream(destFile);
BufferedOutputStream dest = new BufferedOutputStream(fos,
BUFFER);
// read and write until last byte is encountered
while ((currentByte = is.read(data, 0, BUFFER)) != -1) {
dest.write(data, 0, currentByte);
}
dest.flush();
dest.close();
is.close();
}
zip.close();
}
} catch (Exception e) {
Log.e("ERROR: ", "" + e.getMessage());
}
}

Just have a look at http://www.lingala.net/zip4j/download.php , this library file is quick and good .
And you have the short explanation of using the library here
FYI : Here is the another references .
And regarding your code , I have also tried this snippet in my project already but it was ignoring small images while unzipping , so i used the above library . Now i could get it re-solved .

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();
}
}

FileNotFoundException when trying to unzip an archive with java.util.zip.ZipFile

I have a silly problem i haven't been able to figure out. Can anyone help me?
My Code is as:
String zipname = "C:/1100.zip";
String output = "C:/1100";
BufferedInputStream bis = null;
BufferedOutputStream bos = null;
try {
ZipFile zipFile = new ZipFile(zipname);
Enumeration<?> enumeration = zipFile.entries();
while (enumeration.hasMoreElements()) {
ZipEntry zipEntry = (ZipEntry) enumeration.nextElement();
System.out.println("Unzipping: " + zipEntry.getName());
bis = new BufferedInputStream(zipFile.getInputStream(zipEntry));
int size;
byte[] buffer = new byte[2048];
It doesn't create a folder but debugging shows all the contents being generated.
In Order to create a folder i used the code
if(!output.exists()){ output.mkdir();} // here i get an error saying filenotfoundexception
bos = new BufferedOutputStream(new FileOutputStream(new File(outPut)));
while ((size = bis.read(buffer)) != -1) {
bos.write(buffer, 0, size);
}
}
} catch (Exception ex) {
ex.printStackTrace();
} finally {
bos.flush();
bos.close();
bis.close();
}
My zip file contains images: a.jpg b.jpg... and in the same hierarchy, I have abc.xml.
I need to extract the content as is in the zip file.
Any helps here.

There are a few problems with your code: Where is outPut declared? output is not a file but a string, so exists() and mkdir() do not exist. Start by declaring output like:
File output = new File("C:/1100");
Furthermore, outPut (with big P) is not declared. It be something like output + File.seprator + zipEntry.getName().
bos = new BufferedOutputStream(new FileOutputStream(output + File.seprator + zipEntry.getName()));
Note that you don't need to pass a File to FileOutputStream, as constructors show in the documentation.
At this point, your code should work if your Zip file does not contain directory. However, when opening the output stream, if zipEntry.getName() has a directory component (for instance somedir/filename.txt), opening the stream will result in a FileNotFoundException, as the parent directory of the file you try to create does not exist. If you want to be able to handle such zip files, you will find your answer in: How to unzip files recursively in Java?