Need some help to extract ZIP folder which contains inside one more zip file, jar files and folders using java code
public 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();
System.out.println("filePath:"+filePath);
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 void extractFile(ZipInputStream zipIn, String filePath) throws IOException {
BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(filePath));
byte[] bytesIn = new byte[BUFFER_SIZE];
int read = 0;
while ((read = zipIn.read(bytesIn)) != -1) {
bos.write(bytesIn, 0, read);
}
bos.close();
}
I need code for extract outside zip file and inside zip folder using java code.
I was getting fileNotFoundException while executing above code
java.io.FileNotFoundException: C:\siva\Test.zip (The system cannot find the path specified)
at java.io.FileOutputStream.open0(Native Method)
at java.io.FileOutputStream.open(Unknown Source)
at java.io.FileOutputStream.<init>(Unknown Source)
at java.io.FileOutputStream.<init>(Unknown Source)
at com.main.UnzipUtility.extractFile(UnzipUtility.java:62)
at com.main.UnzipUtility.unzip(UnzipUtility.java:40)
at com.main.MainClass.main(MainClass.java:14)
I am currently extracting the contents of a war file and then adding some new files to the directory structure and then creating a new war file.
This is all done programatically from Java - but I am wondering if it wouldn't be more efficient to copy the war file and then just append the files - then I wouldn't have to wait so long as the war expands and then has to be compressed again.
I can't seem to find a way to do this in the documentation though or any online examples.
Anyone can give some tips or pointers?
UPDATE:
TrueZip as mentioned in one of the answers seems to be a very good java library to append to a zip file (despite other answers that say it is not possible to do this).
Anyone have experience or feedback on TrueZip or can recommend other similar libaries?
In Java 7 we got Zip File System that allows adding and changing files in zip (jar, war) without manual repackaging.
We can directly write to files inside zip files as in the following example.
Map<String, String> env = new HashMap<>();
env.put("create", "true");
Path path = Paths.get("test.zip");
URI uri = URI.create("jar:" + path.toUri());
try (FileSystem fs = FileSystems.newFileSystem(uri, env))
{
Path nf = fs.getPath("new.txt");
try (Writer writer = Files.newBufferedWriter(nf, StandardCharsets.UTF_8, StandardOpenOption.CREATE)) {
writer.write("hello");
}
}
As others mentioned, it's not possible to append content to an existing zip (or war). However, it's possible to create a new zip on the fly without temporarily writing extracted content to disk. It's hard to guess how much faster this will be, but it's the fastest you can get (at least as far as I know) with standard Java. As mentioned by Carlos Tasada, SevenZipJBindings might squeeze out you some extra seconds, but porting this approach to SevenZipJBindings will still be faster than using temporary files with the same library.
Here's some code that writes the contents of an existing zip (war.zip) and appends an extra file (answer.txt) to a new zip (append.zip). All it takes is Java 5 or later, no extra libraries needed.
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Enumeration;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;
import java.util.zip.ZipOutputStream;
public class Main {
// 4MB buffer
private static final byte[] BUFFER = new byte[4096 * 1024];
/**
* copy input to output stream - available in several StreamUtils or Streams classes
*/
public static void copy(InputStream input, OutputStream output) throws IOException {
int bytesRead;
while ((bytesRead = input.read(BUFFER))!= -1) {
output.write(BUFFER, 0, bytesRead);
}
}
public static void main(String[] args) throws Exception {
// read war.zip and write to append.zip
ZipFile war = new ZipFile("war.zip");
ZipOutputStream append = new ZipOutputStream(new FileOutputStream("append.zip"));
// first, copy contents from existing war
Enumeration<? extends ZipEntry> entries = war.entries();
while (entries.hasMoreElements()) {
ZipEntry e = entries.nextElement();
System.out.println("copy: " + e.getName());
append.putNextEntry(e);
if (!e.isDirectory()) {
copy(war.getInputStream(e), append);
}
append.closeEntry();
}
// now append some extra content
ZipEntry e = new ZipEntry("answer.txt");
System.out.println("append: " + e.getName());
append.putNextEntry(e);
append.write("42\n".getBytes());
append.closeEntry();
// close
war.close();
append.close();
}
}
I had a similar requirement sometime back - but it was for reading and writing zip archives (.war format should be similar). I tried doing it with the existing Java Zip streams but found the writing part cumbersome - especially when directories where involved.
I'll recommend you to try out the TrueZIP (open source - apache style licensed) library that exposes any archive as a virtual file system into which you can read and write like a normal filesystem. It worked like a charm for me and greatly simplified my development.
You could use this bit of code I wrote
public static void addFilesToZip(File source, File[] files)
{
try
{
File tmpZip = File.createTempFile(source.getName(), null);
tmpZip.delete();
if(!source.renameTo(tmpZip))
{
throw new Exception("Could not make temp file (" + source.getName() + ")");
}
byte[] buffer = new byte[1024];
ZipInputStream zin = new ZipInputStream(new FileInputStream(tmpZip));
ZipOutputStream out = new ZipOutputStream(new FileOutputStream(source));
for(int i = 0; i < files.length; i++)
{
InputStream in = new FileInputStream(files[i]);
out.putNextEntry(new ZipEntry(files[i].getName()));
for(int read = in.read(buffer); read > -1; read = in.read(buffer))
{
out.write(buffer, 0, read);
}
out.closeEntry();
in.close();
}
for(ZipEntry ze = zin.getNextEntry(); ze != null; ze = zin.getNextEntry())
{
out.putNextEntry(ze);
for(int read = zin.read(buffer); read > -1; read = zin.read(buffer))
{
out.write(buffer, 0, read);
}
out.closeEntry();
}
out.close();
tmpZip.delete();
}
catch(Exception e)
{
e.printStackTrace();
}
}
I don't know of a Java library that does what you describe. But what you described is practical. You can do it in .NET, using DotNetZip.
Michael Krauklis is correct that you cannot simply "append" data to a war file or zip file, but it is not because there is an "end of file" indication, strictly speaking, in a war file. It is because the war (zip) format includes a directory, which is normally present at the end of the file, that contains metadata for the various entries in the war file. Naively appending to a war file results in no update to the directory, and so you just have a war file with junk appended to it.
What's necessary is an intelligent class that understands the format, and can read+update a war file or zip file, including the directory as appropriate. DotNetZip does this, without uncompressing/recompressing the unchanged entries, just as you described or desired.
As Cheeso says, there's no way of doing it. AFAIK the zip front-ends are doing exactly the same as you internally.
Anyway if you're worried about the speed of extracting/compressing everything, you may want to try the SevenZipJBindings library.
I covered this library in my blog some months ago (sorry for the auto-promotion). Just as an example, extracting a 104MB zip file using the java.util.zip took me 12 seconds, while using this library took 4 seconds.
In both links you can find examples about how to use it.
Hope it helps.
See this bug report.
Using append mode on any kind of
structured data like zip files or tar
files is not something you can really
expect to work. These file formats
have an intrinsic "end of file"
indication built into the data format.
If you really want to skip the intermediate step of un-waring/re-waring, you could read the war file file, get all the zip entries, then write to a new war file "appending" the new entries you wanted to add. Not perfect, but at least a more automated solution.
Yet Another Solution: You may find code below useful in other situations as well. I have used ant this way to compile Java directories, generating jar files, updating zip files,...
public static void antUpdateZip(String zipFilePath, String libsToAddDir) {
Project p = new Project();
p.init();
Target target = new Target();
target.setName("zip");
Zip task = new Zip();
task.init();
task.setDestFile(new File(zipFilePath));
ZipFileSet zipFileSet = new ZipFileSet();
zipFileSet.setPrefix("WEB-INF/lib");
zipFileSet.setDir(new File(libsToAddDir));
task.addFileset(zipFileSet);
task.setUpdate(true);
task.setProject(p);
task.init();
target.addTask(task);
target.setProject(p);
p.addTarget(target);
DefaultLogger consoleLogger = new DefaultLogger();
consoleLogger.setErrorPrintStream(System.err);
consoleLogger.setOutputPrintStream(System.out);
consoleLogger.setMessageOutputLevel(Project.MSG_DEBUG);
p.addBuildListener(consoleLogger);
try {
// p.fireBuildStarted();
// ProjectHelper helper = ProjectHelper.getProjectHelper();
// p.addReference("ant.projectHelper", helper);
// helper.parse(p, buildFile);
p.executeTarget(target.getName());
// p.fireBuildFinished(null);
} catch (BuildException e) {
p.fireBuildFinished(e);
throw new AssertionError(e);
}
}
this a simple code to get a response with using servlet and send a response
myZipPath = bla bla...
byte[] buf = new byte[8192];
String zipName = "myZip.zip";
String zipPath = myzippath+ File.separator+"pdf" + File.separator+ zipName;
File pdfFile = new File("myPdf.pdf");
ZipOutputStream out = new ZipOutputStream(new FileOutputStream(zipPath));
ZipEntry zipEntry = new ZipEntry(pdfFile.getName());
out.putNextEntry(zipEntry);
InputStream in = new FileInputStream(pdfFile);
int len;
while ((len = in.read(buf)) > 0) {
out.write(buf, 0, len);
}
out.closeEntry();
in.close();
out.close();
FileInputStream fis = new FileInputStream(zipPath);
response.setContentType("application/zip");
response.addHeader("content-disposition", "attachment;filename=" + zipName);
OutputStream os = response.getOutputStream();
int length = is.read(buffer);
while (length != -1)
{
os.write(buffer, 0, length);
length = is.read(buffer);
}
Here are examples how easily files can be appended to existing zip using TrueVFS:
// append a file to archive under different name
TFile.cp(new File("existingFile.txt"), new TFile("archive.zip", "entry.txt"));
// recusively append a dir to the root of archive
TFile src = new TFile("dirPath", "dirName");
src.cp_r(new TFile("archive.zip", src.getName()));
TrueVFS, the successor of TrueZIP, uses Java 7 NIO 2 features under the hood when appropriate but offers much more features like thread-safe async parallel compression.
Beware also that Java 7 ZipFileSystem by default is vulnerable to OutOfMemoryError on huge inputs.
Here is Java 1.7 version of Liam answer which uses try with resources and Apache Commons IO.
The output is written to a new zip file but it can be easily modified to write to the original file.
/**
* Modifies, adds or deletes file(s) from a existing zip file.
*
* #param zipFile the original zip file
* #param newZipFile the destination zip file
* #param filesToAddOrOverwrite the names of the files to add or modify from the original file
* #param filesToAddOrOverwriteInputStreams the input streams containing the content of the files
* to add or modify from the original file
* #param filesToDelete the names of the files to delete from the original file
* #throws IOException if the new file could not be written
*/
public static void modifyZipFile(File zipFile,
File newZipFile,
String[] filesToAddOrOverwrite,
InputStream[] filesToAddOrOverwriteInputStreams,
String[] filesToDelete) throws IOException {
try (ZipOutputStream out = new ZipOutputStream(new FileOutputStream(newZipFile))) {
// add existing ZIP entry to output stream
try (ZipInputStream zin = new ZipInputStream(new FileInputStream(zipFile))) {
ZipEntry entry = null;
while ((entry = zin.getNextEntry()) != null) {
String name = entry.getName();
// check if the file should be deleted
if (filesToDelete != null) {
boolean ignoreFile = false;
for (String fileToDelete : filesToDelete) {
if (name.equalsIgnoreCase(fileToDelete)) {
ignoreFile = true;
break;
}
}
if (ignoreFile) {
continue;
}
}
// check if the file should be kept as it is
boolean keepFileUnchanged = true;
if (filesToAddOrOverwrite != null) {
for (String fileToAddOrOverwrite : filesToAddOrOverwrite) {
if (name.equalsIgnoreCase(fileToAddOrOverwrite)) {
keepFileUnchanged = false;
}
}
}
if (keepFileUnchanged) {
// copy the file as it is
out.putNextEntry(new ZipEntry(name));
IOUtils.copy(zin, out);
}
}
}
// add the modified or added files to the zip file
if (filesToAddOrOverwrite != null) {
for (int i = 0; i < filesToAddOrOverwrite.length; i++) {
String fileToAddOrOverwrite = filesToAddOrOverwrite[i];
try (InputStream in = filesToAddOrOverwriteInputStreams[i]) {
out.putNextEntry(new ZipEntry(fileToAddOrOverwrite));
IOUtils.copy(in, out);
out.closeEntry();
}
}
}
}
}
this works 100% , if you dont want to use extra libs ..
1) first, the class that append files to the zip ..
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;
public class AddZip {
public void AddZip() {
}
public void addToZipFile(ZipOutputStream zos, String nombreFileAnadir, String nombreDentroZip) {
FileInputStream fis = null;
try {
if (!new File(nombreFileAnadir).exists()) {//NO EXISTE
System.out.println(" No existe el archivo : " + nombreFileAnadir);return;
}
File file = new File(nombreFileAnadir);
System.out.println(" Generando el archivo '" + nombreFileAnadir + "' al ZIP ");
fis = new FileInputStream(file);
ZipEntry zipEntry = new ZipEntry(nombreDentroZip);
zos.putNextEntry(zipEntry);
byte[] bytes = new byte[1024];
int length;
while ((length = fis.read(bytes)) >= 0) {zos.write(bytes, 0, length);}
zos.closeEntry();
fis.close();
} catch (FileNotFoundException ex ) {
Logger.getLogger(AddZip.class.getName()).log(Level.SEVERE, null, ex);
} catch (IOException ex) {
Logger.getLogger(AddZip.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
2) you can call it in your controller ..
//in the top
try {
fos = new FileOutputStream(rutaZip);
zos = new ZipOutputStream(fos);
} catch (FileNotFoundException ex) {
Logger.getLogger(UtilZip.class.getName()).log(Level.SEVERE, null, ex);
}
...
//inside your method
addZip.addToZipFile(zos, pathFolderFileSystemHD() + itemFoto.getNombre(), "foto/" + itemFoto.getNombre());
Based on the answer given by #sfussenegger above, following code is used to append to a jar file and download it:
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
Resource resourceFile = resourceLoader.getResource("WEB-INF/lib/custom.jar");
ByteArrayOutputStream baos = new ByteArrayOutputStream();
try (ZipOutputStream zos = new ZipOutputStream(baos, StandardCharsets.ISO_8859_1);) {
try (ZipFile zin = new ZipFile(resourceFile.getFile(), StandardCharsets.ISO_8859_1);) {
zin.stream().forEach((entry) -> {
try {
zos.putNextEntry(entry);
if (!entry.isDirectory()) {
zin.getInputStream(entry).transferTo(zos);
}
zos.closeEntry();
} catch (Exception ex) {
ex.printStackTrace();
}
});
}
/* build file records to be appended */
....
for (FileContents record : records) {
zos.putNextEntry(new ZipEntry(record.getFileName()));
zos.write(record.getBytes());
zos.closeEntry();
}
zos.flush();
}
response.setContentType("application/java-archive");
response.setContentLength(baos.size());
response.setHeader(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=\"custom.jar\"");
try (BufferedOutputStream out = new BufferedOutputStream(response.getOutputStream())) {
baos.writeTo(out);
}
}
I'm having the problem of replacing or updating some files within a certain directory inside a jar file.
I've read a few post already. The code (the JarUpdater Class) given at this link Updating .JAR's contents from code
is being very helpful for me to understand the role and the use of ZipInputStream, ZipOutputStream and ZipEntry, etc..
However, when I run it,
I have an EOF Exception
[EDITED by mk7: I found out the jar file was corrupted after I went through it 20 times or so. So after I replaced the jar file with a new one, the EOF Exception went away. The other two problems below still remains unsolved]
these two new xml files only get copied to the "root directory" of the jar file.
these two new xml files NEVER replaced the two original files inside a directory called /conf.
Which lines of code should I change in order to replace the xml files with the new ones?
With the System.out.println, I did see that the while loop steps through every directory and compare at every file as expected. A new temp jar was also created as expected...
I thought the statement "notInFiles = false" would take care of my need but it's NOT.
How do I step into the /conf and only replace those two files and NOT leave a copy at the root of the jar file?
What am I missing? Thanks for any insight!
Below are the code from that link.
import java.io.*;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;
import java.util.zip.ZipOutputStream;
public class JarUpdater {
public static void main(String[] args) {
File[] contents = {new File("abc.xml"),
new File("def.xml")};
File jarFile = new File("xyz.jar");
try {
updateZipFile(jarFile, contents);
} catch (IOException e) {
e.printStackTrace();
}
}
public static void updateZipFile(File jarFile,
File[] contents) throws IOException {
// get a temp file
File tempFile = File.createTempFile(jarFile.getName(), null);
// delete it, otherwise you cannot rename your existing zip to it.
tempFile.delete();
System.out.println("tempFile is " + tempFile);
boolean renameOk=jarFile.renameTo(tempFile);
if (!renameOk)
{
throw new RuntimeException("could not rename the file "+jarFile.getAbsolutePath()+" to "+tempFile.getAbsolutePath());
}
byte[] buf = new byte[1024];
ZipInputStream zin = new ZipInputStream(new FileInputStream(tempFile));
ZipOutputStream out = new ZipOutputStream(new FileOutputStream(jarFile));
ZipEntry entry = zin.getNextEntry();
while (entry != null) {
String name = entry.getName();
boolean notInFiles = true;
for (File f : contents) {
System.out.println("f is " + f);
if (f.getName().equals(name)) {
// that file is already inside the jar file
notInFiles = false;
System.out.println("file already inside the jar file");
break;
}
}
if (notInFiles) {
System.out.println("name is " + name);
System.out.println("entry is " + entry);
// Add ZIP entry to output stream.
out.putNextEntry(new ZipEntry(name));
// Transfer bytes from the ZIP file to the output file
int len;
while ((len = zin.read(buf)) > 0) {
out.write(buf, 0, len);
}
}
entry = zin.getNextEntry();
}
// Close the streams
zin.close();
// Compress the contents
for (int i = 0; i < contents.length; i++) {
InputStream in = new FileInputStream(contents[i]);
// Add ZIP entry to output stream.
out.putNextEntry(new ZipEntry(contents[i].getName()));
// Transfer bytes from the file to the ZIP file
int len;
while ((len = in.read(buf)) > 0) {
out.write(buf, 0, len);
}
// Complete the entry
out.closeEntry();
in.close();
}
// Complete the ZIP file
out.close();
tempFile.delete();
}
}
In your first cycle (while loop) where you copy the entries which you don't want to replace you don't close the entries in the output zip file. Add out.closeEntry(); like this:
// Add ZIP entry to output stream.
out.putNextEntry(new ZipEntry(name));
// Transfer bytes from the ZIP file to the output file
int len;
while ((len = zin.read(buf)) > 0) {
out.write(buf, 0, len);
}
// ADD THIS LINE:
out.closeEntry();
Also when you check if an entry is to be replaced, you should compare it to a full path, not just to the name of the file. For example if you want to replace abc.xml which is in the /conf folder, you should compare the entry name to "/conf/abc.xml" and not to "abc.xml".
To properly check if an entry is to be replaced:
String name = entry.getName();
boolean notInFiles = true;
for (File f : contents) {
System.out.println("f is " + f);
if (name.equals("/conf/" + f.getName()) {
// that file is already inside the jar file
notInFiles = false;
System.out.println("file already inside the jar file");
break;
}
}
And when you add the entries to the output which are the replaced files, you also have to specify the entry name having full path, e.g. "/conf/abc.xml" and not just "abc.xml" because it would put "abc.xml" in the root of the output zip.
To do this, start the entry name with "/conf/" like this:
// Add ZIP entry to output stream.
out.putNextEntry(new ZipEntry("/conf/" + contents[i].getName()));
For URIs with the protocol jar:file: (usable for all zip files), you can use a zip file system.
URI jarUri = new URI("jar:" + jarFile.toURI().toString()); // "jar:file:/C:/../xyz.jar"
Map<String, String> zipProperties = new HashMap<>();
zipProperties.put("encoding", "UTF-8");
try (FileSystem zipFS = FileSystems.newFileSystem(jarUri, zipProperties)) {
for (File file : contents) {
Path updatePath = zipFS.getPath("/" + file.getName());
Files.delete(updatePath);
Files.copy(file.toPath(), updatePath, StandardCopyOption.REPLACE_EXISTING);
}
} // closes.
One way to derive the URI is prefixing "jar:" to a File.toURI().
This is a bit more elegant and abstract, and also allows Files.copy in and out the zip. Something to keep in ones tool chest.
This is my requirement I have one folder(say: Main folder) which contains three items
One folder and two text files
I want to zip only these three items contained in the Main folder .Right now I am zipping the contents with the Main folder and the resultant zipped folder name is "temp.zip",when I unzip this,I am getting the "Main folder". But my requirement is when I unzip the "temp.zip",it should display only the contents of the Main folder.
Could any one help me in achieving this?
Thank you.
Edit :This is the code I am using to zip the files
This is the code I am zipping the files
public void zipFolder(String srcFolder, String destZipFile)
throws Exception {
ZipOutputStream zip = null;
FileOutputStream fileWriter = null;
fileWriter = new FileOutputStream(destZipFile);
zip = new ZipOutputStream(fileWriter);
addFolderToZip("", srcFolder, zip);
zip.flush();
zip.close();
}
private void addFolderToZip(String path, String srcFolder,
ZipOutputStream zip) throws Exception {
File folder = new File(srcFolder);
for (String fileName : folder.list()) {
if (path.equals("")) {
addFileToZip(folder.getName(), srcFolder + "/" + fileName, zip);
} else {
addFileToZip(path + "/" + folder.getName(), srcFolder + "/"
+ fileName, zip);
}
}
}
private void addFileToZip(String path, String srcFile, ZipOutputStream zip)
throws Exception {
File folder = new File(srcFile);
if (folder.isDirectory()) {
addFolderToZip(path, srcFile, zip);
} else {
byte[] buf = new byte[1024];
int len;
FileInputStream in = new FileInputStream(srcFile);
zip.putNextEntry(new ZipEntry(path + "/" + folder.getName()));
while ((len = in.read(buf)) > 0) {
zip.write(buf, 0, len);
}
}
}
I am calling the zipfolder method with these params :
zipFolder(srcfolder, destipath + "/" + "temp.zip");
Zipping a set of individual files into a single zip in Android should be pretty straight forward. There's a pretty good tutorial here that should get you started:
http://www.jondev.net/articles/Zipping_Files_with_Android_%28Programmatically%29
I just copied from this post
Referred from the matt answer I successfully used this library.
You can try Zip4j, a pure java library to handle zip file. It supports
encryption/decryption of PKWare and AES encryption methods.
http://www.lingala.net/zip4j/
Key features:
Create, Add, Extract, Update, Remove files from a Zip file
Read/Write password protected Zip files
Supports AES 128/256 Encryption
Supports Standard Zip Encryption
Supports Zip64 format
Supports Store (No Compression) and Deflate compression method
Create or extract files from Split Zip files (Ex: z01, z02,...zip)
Supports Unicode file names
Progress Monitor
License:
Zip4j is released under Apache License, Version 2.0
try {
String zipFile = "/locations/data.zip";
String srcFolder = "/locations";
File folder = new File(srcFolder);
String[] sourceFiles = folder.list();
//create byte buffer
byte[] buffer = new byte[1024];
/*
* To create a zip file, use
*
* ZipOutputStream(OutputStream out) constructor of ZipOutputStream
* class.
*/
//create object of FileOutputStream
FileOutputStream fout = new FileOutputStream(zipFile);
//create object of ZipOutputStream from FileOutputStream
ZipOutputStream zout = new ZipOutputStream(fout);
for (int i = 0; i < sourceFiles.length; i++) {
if (sourceFiles[i].equalsIgnoreCase("file.csv") || sourceFiles[i].equalsIgnoreCase("file1.csv")) {
sourceFiles[i] = srcFolder + fs + sourceFiles[i];
System.out.println("Adding " + sourceFiles[i]);
//create object of FileInputStream for source file
FileInputStream fin = new FileInputStream(sourceFiles[i]);
/*
* To begin writing ZipEntry in the zip file, use
*
* void putNextEntry(ZipEntry entry) method of
* ZipOutputStream class.
*
* This method begins writing a new Zip entry to the zip
* file and positions the stream to the start of the entry
* data.
*/
zout.putNextEntry(new ZipEntry(sourceFiles[i].substring(sourceFiles[i].lastIndexOf("/") + 1)));
/*
* After creating entry in the zip file, actually write the
* file.
*/
int length;
while ((length = fin.read(buffer)) > 0) {
zout.write(buffer, 0, length);
}
/*
* After writing the file to ZipOutputStream, use
*
* void closeEntry() method of ZipOutputStream class to
* close the current entry and position the stream to write
* the next entry.
*/
zout.closeEntry();
//close the InputStream
fin.close();
}
}
//close the ZipOutputStream
zout.close();
System.out.println("Zip file has been created!");
} catch (IOException ioe) {
System.out.println("IOException :" + ioe);
}
In windows you can achieve this by the following steps,
1.Open the main folder and select the files which you want to add into zip file
2.Right click -> Add to archieve
3.Choose the archieve format as zip and click 'Ok'
I am working with some file manipulations, just simple read and writes using the java APIs File object.
so here is what I do. first the application receives a zip file, then it extracts the contents on a TEMPFOLDER. And then another class, totally independent, will work on the TEMPFOLDER. It will check the number of files and it should count them all. then it will do stuff to perform some database functions to write the contents of the zip file to the DB
but here is the problem, when I use the application for the first time it goes well smoothly. then WHEN I DO IT THE SECOND TIME AROUND it will fail because the second class which is supposed to check the TEMPFOLDER return 0 as the number of files in the said folder but when I check it manually, it has some contents.
and the pattern it does when I test it continously, it will work, then it will not work, it will work, then it will not work. it acts like that. the reason it does not work is because the application cannot determine correctly the number of files in a folder. it has files but the file object is returning that it has no items in it. but after the error, if you run it again it will work as it is supposed to work.
if you could give out some suggestions from my explanation which is a thousand feet view, i would appreciate it and try it for my debugging. but if you would need some codes, i will post them later
by the way, I am using a web browser and a servlet to accept the zip file
here is the method that i used to write to file system.
public void extractZipAndWriteContentsToFileSystem(ZipFile zipFile) throws IOException, Exception {
Enumeration en = zipFile.entries();
while (en.hasMoreElements()) {
ZipEntry zipEntry = (ZipEntry) en.nextElement();
String name = zipEntry.getName();
long size = zipEntry.getSize();
long compressedSize = zipEntry.getCompressedSize();
File file = new File(zipExtractsTempRepo+name);
if (name.endsWith("/")) {
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);
}
file = null;
parent = null;
is.close();
fos.close();
}
zipFile.close();
traverse(new File(zipExtractsTempRepo));
}
/**
* this method traverses through a folder and its subfolders
* and its subfolders and ...
*
* this method retrieves objects that are files. if it is not
* a file, (then a directory) it looks inside it to look
* for other files
*
* #param file
* #throws IOException
*/
public void traverse(File file) throws IOException {
if (file.isDirectory()) {
File[] allFiles = file.listFiles();
for (File aFile : allFiles) {
traverse(aFile);
}
} else {
FileInputStream in = new FileInputStream(file);
FileOutputStream out = new FileOutputStream(
new File(this.tempRepo + file.getName()));
byte[] bytes = new byte[1024];
int length;
while ((length = in.read(bytes)) >= 0) {
out.write(bytes, 0, length);
}
out.write(4024);
in.close();
out.close();
}
}
now this is the method on the second class to verify the number of file written on a folder
private File[] files;
private File[] zipExtracts;
// location of the tempfolder
tempFolder = new File(RawZipFileHandler.tempRepo);
files = tempFolder.listFiles();
public void checkNumberOfFiles() throws Exception {
Util.out("will check number of files");
// check the number of documents on the tempfile folder
if (files.length != 8) {
throw new Exception ("Number of files expected not met. Expected is 8 got " + files.length);
}
}
comments for my not so pretty code are also welcomed.