Develop Reference

Cannot extract jar file in java application packaged for windows

My program was created in Netbeans 8.0.2. The program is supposed to create a (database) folder after installation and extract the contents of a (database) jar file from its library. The folder gets created quite okay, but the contents of the jar file do not get extracted.
How can I get the extraction of the jar file to work?
NB: When I run the program in Netbeans, everything goes well.
Sample Code:
String appHomeDir = new java.io.File(".").getCanonicalPath();
String destDir = appHomeDir + "/database";
File folder = new File(destDir);
if (!folder.exists()) {
folder.mkdir();
String current = new java.io.File(".").getCanonicalPath();
String jarFile = current + "\\app\\lib\\database.jar";
java.util.jar.JarFile jar = new java.util.jar.JarFile(jarFile);
java.util.Enumeration enumEntries = jar.entries();
while (enumEntries.hasMoreElements()) {
java.util.jar.JarEntry file = (java.util.jar.JarEntry) enumEntries.nextElement();
java.io.File f = new java.io.File(destDir + java.io.File.separator + file.getName());
if (file.isDirectory()) { // if its a directory, create it
f.mkdir();
continue;
}
java.io.InputStream is = jar.getInputStream(file); // get the input stream
java.io.FileOutputStream fos = new java.io.FileOutputStream(f);
while (is.available() > 0) { // write contents of 'is' to 'fos'
fos.write(is.read());
}
fos.close();
is.close();
}
}
So the "database" directory gets created but the contents of "database.jar" do not get extracted.

Problem solved: I replaced "/app/lib/database.jar" with "/lib/database.jar"

FileNotFoundException from new FileOutputStream

I am trying to make a program that will get all files within a jar file, and then copy them.
This is the code I am using to copying files:
public static void copyFolder(File src, File dest)
throws IOException{
if(src.isDirectory()){
//if directory not exists, create it
if(!dest.exists()){
dest.mkdir();
System.out.println("Directory copied from "
+ src + " to " + dest);
}
//list all the directory contents
String files[] = src.list();
for (String file : files) {
//construct the src and dest file structure
File srcFile = new File(src, file);
File destFile = new File(dest, file);
//recursive copy
copyFolder(srcFile,destFile);
}
}else{
//if file, then copy it
//Use bytes stream to support all file types
InputStream in = new FileInputStream(src);
OutputStream out = new FileOutputStream(dest);
byte[] buffer = new byte[1024];
int length;
//copy the file content in bytes
while ((length = in.read(buffer)) > 0){
out.write(buffer, 0, length);
}
in.close();
out.close();
System.out.println("File copied from " + src + " to " + dest);
}
}
But there is an error - java.io.FileNotFoundException: (Access is denied) in OutputStream out = new FileOutputStream(dest);. Now, I have no idea why or what does that really mean? How can I fix it?
Plus, I have absolutely no idea how to extract files from a jar file. I have seen the ZipFile class but I don't really know how to use it... So that leaves me with 3 questions:
1. Whats wrong with the copying code?
2. What does Access is denied mean?
3. Can anyone give me a method for getting files from a jar file? Because jar.listFiles() returns an empty list.
Thanks in advance!

Can anyone give me a method for getting files from a jar file?
I've written some utility classes to work with JARs/ ZIPs based on the NIO.2 File API (the library is Open Source):
Maven:
<dependency>
<groupId>org.softsmithy.lib</groupId>
<artifactId>softsmithy-lib-core</artifactId>
<version>0.4</version>
</dependency>
Tutorial:
http://softsmithy.sourceforge.net/lib/current/docs/tutorial/nio-file/index.html#ExtractJarResourceSample

I can't locate files which created by program

I created a desktop project in netbeans, in the project folder I have three files : file.txt, file2.txt and file3.txt, in the load of the program I want to call these three files, and this is the code I tried :
public void run() {
Path path = Paths.get("file.txt");
Path path2 = Paths.get("file2.txt");
Path path3 = Paths.get("file3.txt");
if(Files.exists(path) && Files.exists(path2) && Files.exists(path3)) {
lireFichiers();
}else{
JOptionPane.showConfirmDialog(null, "Files didn't found !");
}
}
but when I run my program I get the message : "Files didn't found !" which means he didn't found those files.
those files are created by this code :
File file = new File("Id.txt");
File file2 = new File("Pass.txt");
File file3 = new File("Remember.txt");

The following three lines will only create file handlers for your program to use. This will not create a file by itself. If you are using the handler to write it will also create a file for you provided you close correctly after writing.
File file = new File("Id.txt");
File file2 = new File("Pass.txt");
File file3 = new File("Remember.txt");
So, a sample code will look like:
File file = new File("Id.txt");
FileWriter fw = new FileWriter(file);
try
{
// write to file
}
finally
{
fw.close();
}

If the file is in the root of your project, this should work:
Path path = Paths.get("foo.txt");
System.out.println(Files.exists(path)); // true
Where exatlcy are the files you want to open in your project?

Please specify the language you use.
Generally you could search the file to see whether the files are in the program bootup folder. For webapps you should pay attention to the "absolute path and the relative path".
=========Edit============
If you are using Jave, then the file should be write out using FileWriter.close() before you can find them in your hard disk.
Ref

Thank you all for your help, I just tried this :
File file = new File("Id.txt");
File file2 = new File("Pass.txt");
File file3 = new File("Remember.txt");
if(file.exists() && file2.exists() && file3.exists()){
// manipulation
}
and it works

Extract a .tar.gz file in java (JSP)

I can't seem to import the packages needed or find any online examples of how to extract a .tar.gz file in java.
What makes it worse is I'm using JSP pages and am having trouble importing packages into my project. I'm copying the .jar's into WebContent/WEB-INF/lib/ and then right clicking on the project and selecting import external jar and importing it. Sometimes the packages resolve, other times they don't. Can't seem to get GZIP to import either. The imports in eclipse for jsp aren't intuitive like they are in normal Java code where you can right click a recognized package and select import.
I've tried the Apache commons library, the ice and another one called JTar. Ice has imported, but I can't find any examples of how to use it?
I guess I need to uncompress the gzipped part first, then open it with the tarstream?
Any help is greatly appreciated.

The accepted answer works fine, but I think it is redundant to have a write to file operation.
You could use something like
TarArchiveInputStream tarInput =
new TarArchiveInputStream(new GZipInputStream(new FileInputStream("Your file name")));
TarArchiveEntry currentEntry = tarInput.getNextTarEntry();
while(currentEntry != null) {
File f = currentEntry.getFile();
// TODO write to file as usual
}
Hope this help.
Maven Repo

Ok, i finally figured this out, here is my code in case this helps anyone in the future.
Its written in Java, using the apache commons io and compress librarys.
File dir = new File("directory/of/.tar.gz/files/here");
File listDir[] = dir.listFiles();
if (listDir.length!=0){
for (File i:listDir){
/* Warning! this will try and extract all files in the directory
if other files exist, a for loop needs to go here to check that
the file (i) is an archive file before proceeding */
if (i.isDirectory()){
break;
}
String fileName = i.toString();
String tarFileName = fileName +".tar";
FileInputStream instream= new FileInputStream(fileName);
GZIPInputStream ginstream =new GZIPInputStream(instream);
FileOutputStream outstream = new FileOutputStream(tarFileName);
byte[] buf = new byte[1024];
int len;
while ((len = ginstream.read(buf)) > 0)
{
outstream.write(buf, 0, len);
}
ginstream.close();
outstream.close();
//There should now be tar files in the directory
//extract specific files from tar
TarArchiveInputStream myTarFile=new TarArchiveInputStream(new FileInputStream(tarFileName));
TarArchiveEntry entry = null;
int offset;
FileOutputStream outputFile=null;
//read every single entry in TAR file
while ((entry = myTarFile.getNextTarEntry()) != null) {
//the following two lines remove the .tar.gz extension for the folder name
String fileName = i.getName().substring(0, i.getName().lastIndexOf('.'));
fileName = fileName.substring(0, fileName.lastIndexOf('.'));
File outputDir = new File(i.getParent() + "/" + fileName + "/" + entry.getName());
if(! outputDir.getParentFile().exists()){
outputDir.getParentFile().mkdirs();
}
//if the entry in the tar is a directory, it needs to be created, only files can be extracted
if(entry.isDirectory){
outputDir.mkdirs();
}else{
byte[] content = new byte[(int) entry.getSize()];
offset=0;
myTarFile.read(content, offset, content.length - offset);
outputFile=new FileOutputStream(outputDir);
IOUtils.write(content,outputFile);
outputFile.close();
}
}
//close and delete the tar files, leaving the original .tar.gz and the extracted folders
myTarFile.close();
File tarFile = new File(tarFileName);
tarFile.delete();
}
}

Android unzip not a directory issue

I am trying to unzip a zip file which is stored in the raw folder. Code is as follows
try
{
File myDir = new File(getFilesDir().getAbsolutePath());
File newFile = new File(myDir + "/imageFolder");
if(!newFile.exists())
{
newFile.mkdir();
}
ZipInputStream zipIs = new ZipInputStream(con
.getResources().openRawResource(R.raw.images));
ZipEntry ze = null;
while ((ze = zipIs.getNextEntry()) != null)
{
Log.v("Name", ze.getName());
Log.v("Size", "" + ze.getSize());
if(ze.getSize() >0)
{
FileOutputStream fout = new FileOutputStream(newFile
+ "/" + ze.getName());
byte[] buffer = new byte[1024];
int length = 0;
while ((length = zipIs.read(buffer)) > 0)
{
fout.write(buffer, 0, length);
}
zipIs.closeEntry();
fout.close();
}
}
zipIs.close();
} catch (Exception e)
{
e.printStackTrace();
}
But I keep getting this error
01-18 11:24:28.301: W/System.err(2285): java.io.FileNotFoundException:
/data/data/com.example.ziptests/files/imageFolder/TestImages/background.png
(Not a directory)
I have absolutely no idea why it is causing this, it finds the files, but when it comes to writing them out, it brings up that error. Originally I found a problem that was caused by having the zip file zipped up on the mac, so I zipped up the file on my windows machine instead, that got rid of one problem (when you zip on a mac, it adds these extra folders and files such s store.ds which causes an error when trying to unzip), but this not a directory error keeps coming up.
Any ideas why this is happening?

Please try below link code for unzip zip file.
Code for Extract Zip File
Unzip Zip File
The Problem is I am Uploading zip File which is not made using winrar software, so it is not proper extracted and give me error.
It will solve your problem.

You can't write files to the raw folder. It is a read only dir intended to contain resource files included in your apk.
UPDATE
That file would be better in the assets directory. You can access it through the AssetManager. If not, leave it in the res/raw dir, but access it through Resources.openRawResource. Either way they are Read-Only.