Develop Reference

Unable to delete specific files after unzipping the files

Am new to Java, I searched in google for unzipping the files. Tested the code in my local and am able to unzip the files.
But unable to delete the files I tried some logic but no luck.
Can anyone help me how read a particular file and delete that file using its path and also need to delete a specific folder using its path and delete recursively. all the other files need to be there
Below is the code:
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.file.DirectoryStream;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;
public class UnzipFiles {
public static void main(String[] args) {
String zipFilePath = "/Users/Safeer_Pasha/Music/archive.zip";
String destDir = "/Workspace/";
unzip(zipFilePath, destDir);
}
private static void unzip(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){
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();
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();
}
}
}

File Not Found Exception, Access is Denied, Java

I made a Program which moves all files of a folder to another folder but when I'm executing the Program it shows me java.io.FileNotFound Exception and Access is denied
I tried to fix this error but it is still giving me the same error.
What am I doing wrong?
I have also attached the screenshot of Error I am getting.
when I checked the properties of the folder it was read-only, I changed but still, the Issue Persists
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
public class MoveFile
{
public static void main(String\[\] args)
{
InputStream inStream = null;
OutputStream outStream = null;
try{
File afile =new File("C:\\Users\\admin\\Desktop\\A");
File bfile =new File("C:\\Users\\admin\\Desktop\\B");
inStream = new FileInputStream(afile);
outStream = new FileOutputStream(bfile);
byte\[\] buffer = new byte\[1024\];
int length;
while ((length = inStream.read(buffer)) > 0){
outStream.write(buffer, 0, length);
}
inStream.close();
outStream.close();
afile.delete();
System.out.println("File Moved!");
}catch(IOException e){
e.printStackTrace();
}
}
}
I expect the Files of folder A to move in Folder B.

according to your question description , you try to move all file of a folder to another folder...
to do this you can use this code ....
public static void main(String[] args) throws IOException {
String from = "C:/Users/Infra/Desktop/PBL/A";
String to = "C:/Users/Infra/Desktop/PBL/B";
File folder = new File(from);
File[] listOfFiles = folder.listFiles();
for (File file : listOfFiles) {
Path temp = Files.move(Paths.get(from +"/"+ file.getName()),
Paths.get(to +"/"+ file.getName()));
}
}

How to read data from nested zip files in Java without using temporary files?

I am trying to to extract files out of a nested zip archive and process them in memory.
What this question is not about:
How to read a zip file in Java: NO, the question is how to read a zip file within a zip file within a zip and so on and so forth (as in nested zip files).
Write temporary results on disk: NO, I'm asking about doing it all in memory. I found many answers using the not-so-efficient technique of writing results temporarily to disk, but that's not what I want to do.
Example:
Zipfile -> Zipfile1 -> Zipfile2 -> Zipfile3
Goal: extract the data found in each of the nested zip files, all in memory and using Java.
ZipFile is the answer, you say? NO, it is not, it works for the first iteration, that is for:
Zipfile -> Zipfile1
But once you get to Zipfile2, and perform a:
ZipInputStream z = new ZipInputStream(zipFile.getInputStream( zipEntry) ) ;
you will get a NullPointerException.
My code:
public class ZipHandler {
String findings = new String();
ZipFile zipFile = null;
public void init(String fileName) throws AppException{
try {
//read file into stream
zipFile = new ZipFile(fileName);
Enumeration<?> enu = zipFile.entries();
exctractInfoFromZip(enu);
zipFile.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
//The idea was recursively extract entries using ZipFile
public void exctractInfoFromZip(Enumeration<?> enu) throws IOException, AppException{
try {
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);
// directory ?
if (zipEntry.isDirectory()) {
System.out.println("dir found:" + name);
findings+=", " + name;
continue;
}
if (name.toUpperCase().endsWith(".ZIP") || name.toUpperCase().endsWith(".GZ")) {
String fileType = name.substring(
name.lastIndexOf(".")+1, name.length());
System.out.println("File type:" + fileType);
System.out.println("zipEntry: " + zipEntry);
if (fileType.equalsIgnoreCase("ZIP")) {
//ZipFile here returns a NULL pointer when you try to get the first nested zip
ZipInputStream z = new ZipInputStream(zipFile.getInputStream(zipEntry) ) ;
System.out.println("Opening ZIP as stream: " + name);
findings+=", " + name;
exctractInfoFromZip(zipInputStreamToEnum(z));
} else if (fileType.equalsIgnoreCase("GZ")) {
//ZipFile here returns a NULL pointer when you try to get the first nested zip
GZIPInputStream z = new GZIPInputStream(zipFile.getInputStream(zipEntry) ) ;
System.out.println("Opening ZIP as stream: " + name);
findings+=", " + name;
exctractInfoFromZip(gZipInputStreamToEnum(z));
} else
throw new AppException("extension not recognized!");
} else {
System.out.println(name);
findings+=", " + name;
}
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("Findings " + findings);
}
public Enumeration<?> zipInputStreamToEnum(ZipInputStream zStream) throws IOException{
List<ZipEntry> list = new ArrayList<ZipEntry>();
while (zStream.available() != 0) {
list.add(zStream.getNextEntry());
}
return Collections.enumeration(list);
}

I have not tried it but using ZipInputStream you can read any InputStream that contains a ZIP file as data. Iterate through the entries and when you found the correct entry use the ZipInputStreamto create another nestedZipInputStream`.
The following code demonstrates this. Imagine we have a readme.txt inside 0.zip which is again zipped in 1.zip which is zipped in 2.zip. Now we read some text from readme.txt:
try (FileInputStream fin = new FileInputStream("D:/2.zip")) {
ZipInputStream firstZip = new ZipInputStream(fin);
ZipInputStream zippedZip = new ZipInputStream(findEntry(firstZip, "1.zip"));
ZipInputStream zippedZippedZip = new ZipInputStream(findEntry(zippedZip, "0.zip"));
ZipInputStream zippedZippedZippedReadme = findEntry(zippedZippedZip, "readme.txt");
InputStreamReader reader = new InputStreamReader(zippedZippedZippedReadme);
char[] cbuf = new char[1024];
int read = reader.read(cbuf);
System.out.println(new String(cbuf, 0, read));
.....
public static ZipInputStream findEntry(ZipInputStream in, String name) throws IOException {
ZipEntry entry = null;
while ((entry = in.getNextEntry()) != null) {
if (entry.getName().equals(name)) {
return in;
}
}
return null;
}
Note the code is really ugly and does not close anything nor does it checks for errors. It is just a minimized version that demonstrates how it works.
Theoretically there is no limit how many ZipInputStreams you cascade into another. The data is never written into a temporary file. The decryption is only performed on-demand when you read each InputStream.

this is the way I found to unzip file in memory:
The code is not clean AT ALL, but i understand the rules are to post something working, so i have this hopefully to help so
What I do is use a recursive method to navigate the complex ZIP file and extract
folder
other inner zips
files
and save the results in memory to later work with them.
Main things I found I want to share with you:
1 ZipFile is useless if you have nested zip files
2 You have to use the basic Zip InputStream and Outputstream
3 I only use recursive programming to unzip nested zips
package course.hernan;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayDeque;
import java.util.Deque;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;
import java.util.zip.ZipOutputStream;
import org.apache.commons.io.IOUtils;
public class FileReader {
private static final int BUFFER_SIZE = 2048;
public static void main(String[] args) {
try {
File f = new File("DIR/inputs.zip");
FileInputStream fis = new FileInputStream(f);
BufferedInputStream bis = new BufferedInputStream(fis);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
BufferedOutputStream bos = new BufferedOutputStream(baos);
byte[] buffer = new byte[BUFFER_SIZE];
while (bis.read(buffer, 0, BUFFER_SIZE) != -1) {
bos.write(buffer);
}
bos.flush();
bos.close();
bis.close();
//This STACK has the output byte array information
Deque<Map<Integer, Object[]>> outputDataStack = ZipHandler1.unzip(baos);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
package course.hernan;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Deque;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.SortedMap;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;
import org.apache.commons.lang3.StringUtils;
public class ZipHandler1 {
private static final int BUFFER_SIZE = 2048;
private static final String ZIP_EXTENSION = ".zip";
public static final Integer FOLDER = 1;
public static final Integer ZIP = 2;
public static final Integer FILE = 3;
public static Deque<Map<Integer, Object[]>> unzip(ByteArrayOutputStream zippedOutputFile) {
try {
ZipInputStream inputStream = new ZipInputStream(
new BufferedInputStream(new ByteArrayInputStream(
zippedOutputFile.toByteArray())));
ZipEntry entry;
Deque<Map<Integer, Object[]>> result = new ArrayDeque<Map<Integer, Object[]>>();
while ((entry = inputStream.getNextEntry()) != null) {
LinkedHashMap<Integer, Object[]> map = new LinkedHashMap<Integer, Object[]>();
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
System.out.println("\tExtracting entry: " + entry);
int count;
byte[] data = new byte[BUFFER_SIZE];
if (!entry.isDirectory()) {
BufferedOutputStream out = new BufferedOutputStream(
outputStream, BUFFER_SIZE);
while ((count = inputStream.read(data, 0, BUFFER_SIZE)) != -1) {
out.write(data, 0, count);
}
out.flush();
out.close();
// recursively unzip files
if (entry.getName().toUpperCase().endsWith(ZIP_EXTENSION.toUpperCase())) {
map.put(ZIP, new Object[] {entry.getName(), unzip(outputStream)});
result.add(map);
//result.addAll();
} else {
map.put(FILE, new Object[] {entry.getName(), outputStream});
result.add(map);
}
} else {
map.put(FOLDER, new Object[] {entry.getName(), unzip(outputStream)});
result.add(map);
}
}
inputStream.close();
return result;
} catch (Exception e) {
throw new RuntimeException(e);
}
}

Thanks to JMax.
In my case, The result of reading the pdf file is different from the expected result, It becomes bigger and cannot be opened.
Finally I found that I had made a mistake, The buffer may not be full，
The following is the error code.
while((n = zippedZippedZippedReadme.read(buffer)) != -1) {
fos.write(buffer);
}
Here is the correct code,
try (FileInputStream fin = new FileInputStream("1.zip")) {
ZipInputStream firstZip = new ZipInputStream(fin);
ZipInputStream zippedZip = new ZipInputStream(findEntry(firstZip, "0.zip"));
ZipInputStream zippedZippedZippedReadme = findEntry(zippedZip, "test.pdf");
long startTime = System.currentTimeMillis();
byte[] buffer = new byte[4096];
File outputFile = new File("test.pdf");
try (FileOutputStream fos = new FileOutputStream(outputFile)) {
int n;
while((n = zippedZippedZippedReadme.read(buffer)) != -1) {
fos.write(buffer, 0 ,n);
}
fos.flush();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
System.out.println("time consuming:" + (System.currentTimeMillis() - startTime)/1000.0);
}
hope to be helpful!

How to zip files and folders in Java?

Please have a look at the below code.
public void startCompress(String path,String fileName,String outputLocation,int compressType,int filSize) throws Exception
{
System.out.println("Input Location: "+path);
System.out.println("Output Location: "+outputLocation);
System.out.println(compressType);
byte[] bs=new byte[filSize];
System.out.println(filSize);
FileOutputStream fos=new FileOutputStream(outputLocation+"/test.zip");
System.out.println(fos.toString());
ZipOutputStream zos=new ZipOutputStream(fos);
ZipEntry ze = new ZipEntry(fileName);
zos.putNextEntry(ze);
FileInputStream inputStream=new FileInputStream(path);
int len;
while((len=inputStream.read(bs))>0){
zos.write(bs, 0, len);
}
inputStream.close();
zos.closeEntry();
zos.close();
}
In above code, we compress a file using java.util.zip package. But we have an issue. That is, if we select multiple files then only one file is being compressed. If we select a folder, the compression simply won't work.
How can I fix this to compress either a file, files, folder, folders, or even nested folders? Java zip package does support .zip, .tar, .tarGz and tarZ. So the solution should not be something which is limited to .zip extension as well.

Here is my solution that uses the new java.nio package. Just call zipDir giving it the path to the directory. It will create a zip file in the same location but called <directory>.zip.
private static Path buildPath(final Path root, final Path child) {
if (root == null) {
return child;
} else {
return Paths.get(root.toString(), child.toString());
}
}
private static void addZipDir(final ZipOutputStream out, final Path root, final Path dir) throws IOException {
try (DirectoryStream<Path> stream = Files.newDirectoryStream(dir)) {
for (Path child : stream) {
Path entry = buildPath(root, child.getFileName());
if (Files.isDirectory(child)) {
addZipDir(out, entry, child);
} else {
out.putNextEntry(new ZipEntry(entry.toString()));
Files.copy(child, out);
out.closeEntry();
}
}
}
}
public static void zipDir(final Path path) throws IOException {
if (!Files.isDirectory(path)) {
throw new IllegalArgumentException("Path must be a directory.");
}
BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(path.toString() + ".zip"));
try (ZipOutputStream out = new ZipOutputStream(bos)) {
addZipDir(out, path.getFileName(), path);
}
}

The zip libraries for java cannot be used to compress folders in simpler way like - compress this folder.
You need to do the test if the input is folder or file by yourself. If it is a file - add it to the zip. If it is a folder - iterate the folder and add each file to the zip. For the subfolders to the same. To add more than one file to the Zip you need to create ZipEntry for each file.
You can try this code which works for me:
public static void zip(File directory, File zipfile) throws IOException {
URI base = directory.toURI();
Deque<File> queue = new LinkedList<File>();
queue.push(directory);
OutputStream out = new FileOutputStream(zipfile);
Closeable res = out;
try {
ZipOutputStream zout = new ZipOutputStream(out);
res = zout;
while (!queue.isEmpty()) {
directory = queue.pop();
for (File kid : directory.listFiles()) {
String name = base.relativize(kid.toURI()).getPath();
if (kid.isDirectory()) {
queue.push(kid);
name = name.endsWith("/") ? name : name + "/";
zout.putNextEntry(new ZipEntry(name));
} else {
zout.putNextEntry(new ZipEntry(name));
copy(kid, zout);
zout.closeEntry();
}
}
}
} finally {
res.close();
}
}

Updated from this answer, which fixes issue with each file been added to it's own directory. Also better supports Windows explorer.
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;
public class Test {
public static void main(String agrs[]) {
ZipUtils appZip = new ZipUtils();
appZip.zipIt(new File(source directory), new File(dest zip));
}
public static class ZipUtils {
private final List<File> fileList;
private List<String> paths;
public ZipUtils() {
fileList = new ArrayList<>();
paths = new ArrayList<>(25);
}
public void zipIt(File sourceFile, File zipFile) {
if (sourceFile.isDirectory()) {
byte[] buffer = new byte[1024];
FileOutputStream fos = null;
ZipOutputStream zos = null;
try {
// This ensures that the zipped files are placed
// into a folder, within the zip file
// which is the same as the one been zipped
String sourcePath = sourceFile.getParentFile().getPath();
generateFileList(sourceFile);
fos = new FileOutputStream(zipFile);
zos = new ZipOutputStream(fos);
System.out.println("Output to Zip : " + zipFile);
FileInputStream in = null;
for (File file : this.fileList) {
String path = file.getParent().trim();
path = path.substring(sourcePath.length());
if (path.startsWith(File.separator)) {
path = path.substring(1);
}
if (path.length() > 0) {
if (!paths.contains(path)) {
paths.add(path);
ZipEntry ze = new ZipEntry(path + "/");
zos.putNextEntry(ze);
zos.closeEntry();
}
path += "/";
}
String entryName = path + file.getName();
System.out.println("File Added : " + entryName);
ZipEntry ze = new ZipEntry(entryName);
zos.putNextEntry(ze);
try {
in = new FileInputStream(file);
int len;
while ((len = in.read(buffer)) > 0) {
zos.write(buffer, 0, len);
}
} finally {
in.close();
}
}
zos.closeEntry();
System.out.println("Folder successfully compressed");
} catch (IOException ex) {
ex.printStackTrace();
} finally {
try {
zos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
protected void generateFileList(File node) {
// add file only
if (node.isFile()) {
fileList.add(node);
}
if (node.isDirectory()) {
File[] subNote = node.listFiles();
for (File filename : subNote) {
generateFileList(filename);
}
}
}
}
}

java.io.filenotfoundexception downloading zip and extracting it

I made a small program to download a zip file from a direct link and after that extract all contents of it in the same directory.
It doesn't download anything and it also doesn't extract.
This is what I have so far:
package main;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.URL;
import java.nio.channels.Channels;
import java.nio.channels.ReadableByteChannel;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;
public class Main {
static String url = "https://www.dropbox.com/s/uml938guklfvo7r/Tekst.zip?dl=1";
static int lastSlashIndex = url.lastIndexOf('/');
static String filename= url.substring(lastSlashIndex + 1, url.length() - 5);
static String filepath = "C:";
private static final int BUFFER = 4096;
public static void main(String[] args) {
try{
URL website = new URL(url);
ReadableByteChannel rbc;
rbc = Channels.newChannel(website.openStream());
new File(filepath + filename).createNewFile();
FileOutputStream fos = new FileOutputStream(filepath + filename);
fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
fos.close();
}catch(Exception e){ e.printStackTrace(); }
try {
unzip(filepath + filename, filepath);
} catch (IOException e) {
e.printStackTrace();
}
}
public static void unzip(String zipFilePath, String destDirectory) throws IOException {
File destDir = new File(destDirectory);
if (!destDir.exists()) {
destDir.mkdir();
}
ZipInputStream zipIn = new ZipInputStream(new FileInputStream(zipFilePath));
ZipEntry entry = zipIn.getNextEntry();
// iterates over entries in the zip file
while (entry != null) {
String filePath = destDirectory + File.separator + entry.getName();
if (!entry.isDirectory()) {
// if the entry is a file, extracts it
extractFile(zipIn, filePath);
} else {
// if the entry is a directory, make the directory
File dir = new File(filePath);
dir.mkdir();
}
zipIn.closeEntry();
entry = zipIn.getNextEntry();
}
zipIn.close();
}
private static void extractFile(ZipInputStream zipIn, String filePath) throws IOException {
Line 68>> BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(filePath));
byte[] bytesIn = new byte[BUFFER];
int read = 0;
while ((read = zipIn.read(bytesIn)) != -1) {
bos.write(bytesIn, 0, read);
}
bos.close();
}
}
Here is the error:
java.io.FileNotFoundException: C:\Tekst.txt (Access is denied)
at java.io.FileOutputStream.open(Native Method)
at java.io.FileOutputStream.<init>(Unknown Source)
at java.io.FileOutputStream.<init>(Unknown Source)
at main.Main.extractFile(Main.java:68)
at main.Main.unzip(Main.java:55)
at main.Main.main(Main.java:35)

Apparently this file is simply not created yet. You can create it with
new File(yourFilepath).createNewFile()
and you need to do it before you invoke
FileOutputStream fos = new FileOutputStream(filepath + filename);
which throws the exception. Then it works perfectly fine.