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Java .list() in a jar file

int x = new File("src/Images").list().length;
It works fine for me until I want to run it as an executable jar file.
"/Images" & "Images" won't work and I've read that I can't use new File inside a jar.
I want the jar file to run, locate the file inside and count the amount of images in the folder.
Is there a simple alternative to the above line of code?
I've tried playing with DirectoryStream and a few other things but have had no luck.
Cheers

It usually uses the directory of .jar file as root directory.
The easiest way to "make it work" is this: Having folder src in the same folder as the .jar file and in src folder put the Images folder.
So it looks like this, when you execute the .jar:
...../myproject/myproject.jar
...../myproject/src/Images

eclipse create jar file with txt file that can be referred to

I have a project in eclipse
foo_project
- src
- bar_package
bam.java
info.txt
- info.txt
- resources
- info.txt
In bam.java, say, I print the content of info.txt out like
try {
welcome = new BufferedReader(new FileReader("src/info.txt"));
String currentLine = null;
while ( (currentLine = welcome.readLine()) != null) {
System.out.println(currentLine);
}
welcome.close();
} catch (Exception fof) {
System.err.println(fof.toString());
}
It is working inside eclipse as it is when I put info.txt under src folder, however, it doesn't work once I export this project to a JAR file.
In the code, I tried just "info.txt" as well as "src/info.txt", none of them is working! As you can see, I put info.txt pretty much everywhere and not successful!
How can I refer to this info.txt in the Java code, and make Java find it at both inside eclipse and JAR file?

If the text in your info.txt will always be the same, instead of treating the text as a file, consider treating it as a "resource". If you do that , you can include it within your JAR, instead of having to distribute it as a separate file.
You open an InputStream to a resource using the Class.getResourceAsStream() method.

I think to load files from Jar file the file reader method will not work effectively, you will have to use class.getResource() or class.getResourceAsStream() methods
some helpful links,
Load a resource contained in a jar
How to load resource from jar file packaged in a war file?
Load resource from class's own JAR file
Also as others have suggested make sure the Jar file contains the txt file you looking for, you can either use "jar" command or winRAR

To access resources inside a JAR file, you need to use
YourClass.getClassLoader().getResourceAsStream("info.txt")
This way it will look inside the JAR file (or rather, in all places on the classpath) for the file as a Resource. It will work in both Eclipse and when packaged as a JAR.

I ended up using in the class
getClass().getResourceAsStream( "/info.txt") which gives an InputStream
Then I use InputStreamReader and BufferedReader to read out the file.
/ here is the src folder. Everything under this folder will be built to bin folder at the end.
If you have multiple source folders (a folder can be set to be source folder by right click and choose that option in Eclipse), all source folders built to single bin folder
For example,
if you have source folders
sourceA
foo_package/...
sourceB
bar_package/...
then in bin, it will be
bin (this is the "/")
foo_package/...
bar_package/...
Thanks for all the answers and inspiration to all!

you must put your txt file next to the jar file in your jar folder
it means that copy your txt file into your jar file folder not into jar file

access files and folders in executable jars

I am facing the following problem:
I use Eclipse for my Java projects and there I have the following structure:
--> src
--> package1
....
--> package2
...
-->dataFolder
--> Folder1
--> file1.xml
--> Folder2
file2.xml
In my java project I parse all files in the dataFolder directory. This is no problem because I can just use the root directory of the eclipse project, like this:
File dataStoreFolder = new File("dataFolder");
Some parsing......
But when I export my project as an executable jar file, I can not access these files anymore. Of course thats because they are not in the same folder where I put my exec.jar file. But I do not want to copy the whole folder with the data to my exec.jar file. Can I put it somehow inside my jar file? (I did it by adding the dataFolder to the Java Build Path but it still does not work as it does in Eclipse)
Can someone help me please?

When you're using a jar file, those files don't exist as files any more.
You can absolutely include the data in your jar file, but then you'll need to change the code which accesses it, too. Instead of creating a File object, you'll need something like:
InputStream input = Foo.class.getResourceAsStream("/dataFolder/Folder1/file.xml");
So you have two separable tasks:
Work out how to include the data folder within your jar file
Change your code to access the data appropriately

Yes, you can put them in your jar file. Just make dataFolder a source folder under Eclipse, and it will copy the non-Java files to the target directory, and add them to the jar file.
Once in the jar file, you would get file1.xml like this:
InputStream in = SomeClass.class.getResourceAsStream("/Folder1/file1.xml");

Access a file from a JAR in the same folder

I need to acces (create and read) a file from a JAR file (executable jar),
and that file should be created in the same directory as the JAR
I tried
this.getClass().getResource("myFile")
but since the jar has packages in it, it won't work..
I also tried write just
File f = new File("myFile");
f.createNewFile();
and that works if i execute the JAR from the terminal, but if i execute the JAR by double-clicking it, the file is created in my home directory -.-''
how do i access a file being SURE that that file is in the SAME directory as the JAR file?
(of course also getting the jar absolute path would do the trick since i can get the parent folder from it)

This will give you the full path to the Jar:
String path = this.getClass().getProtectionDomain().getCodeSource().getLocation().getPath();
EDIT: sorry, was in javascript mode when I wrote that :). As was so politely requested, in a static method you should be able to do this:
String path = Me.class.getProtectionDomain().getCodeSource().getLocation().getPath();
(where the class name is Me).

Java JAR: Writing to a file

Currently, in my eclipse project, I have a file that I write to. However, I have exported my project to a JAR file and writing to that directory no longer works. I know I need to treat this file as a classpath resource, but how do I do this with a BufferedWriter?

You shouldn't have to treat it as a classpath resource to write to a file. You would only have to do that if the file was in your JAR file, but you don't want to write to a file contained within your JAR file do you?
You should still be able to create and write to a file but it will probably be relative to the working directory - the directory you execute your JAR file from (unless you use an absolute path). In eclipse, configure the working directory from within the run configuration dialog.

You're probably working in Linux. Because, in Linux, when you start your application from a JAR, the working directory is set to your home folder (/home/yourname/). When you start it from Eclipse, the working directory is set to the project folder.
To make sure you really know the files you are using are located in the project folder, or the folder where your JAR is in, you can use this piece of code to know where the JAR is located, then use the File(File parent, String name) constructor to create your files:
// Find out where the JAR is:
String path = YourClass.class.getProtectionDomain().getCodeSource().getLocation().toURI().getPath();
path = path.substring(0, path.lastIndexOf('/')+1);
// Create the project-folder-file:
File root = new File(path);
And, from now on, you can create all your File's like this:
File myFile = new File(root, "config.xml");
Of course, root has to be in your scope.

Such resources (when altered) are best stored in a sub-directory of user.home. It is a reproducible path that the user should have write access to. You might use the package name of the main class as a basis for the sub-directory. E.G.
our.com.Main -> ${user.home}/our/com/