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Java can't get relative path for file

Image DescriptionTrying to access a test.txt file that is in the same location as my HelloController.java file but for some reason, it is showing that the file does not exist. I've tried moving the file around but it does not work.
Using the absolute path works, but this is a shared project so it will be ran on other computers. Any suggestions would be much appreciated.

Your best bet is to add it to the class path and reading it as a class path resource.

The relative path root is your "working directory". Which means if you try to access "." you will start at your working directory. This directory is only set once for your application and is normally the folder which was opened when you started it.
When working with IDEs (like in your case) the working directory will be the root folder of your project (So the folder in which the pom.xml and src folders are located.
If you want to access the file via the normal file API you are currently using, just put the file in that diretory and it should work (given you share it with the other people in the same location).
If you need the file to be inside your generated output jar-file, you will need to use the File as a resource (See duffymo's answer), as the file does not exist by itself on the file system, but as a file inside your jar-file.
If you want to know your current working directory, you can create a File refrence to "." and expand it to an absolute path (Which will replace refrences like "." and ".." and generate a file path from your root) and then write it to the console. This would look something like this:
// Get refrence to the current working directory
File workingDirectoryReference = new File(".");
// Convert it to an absolute path string
String absolutePath = workingDirectoryReference.getAbsolutePath();
// Output to console
System.out.println(absolutePath );

How do I get the relative path of files in my project?

I am creating a project using jsp/servlet in which I am trying to create java file and class file inside the project itself. But I am able to do this for only my system because the path I give their is like : C:\Users\MySystem\Desktop\Test\.. which works only for my system. What should I do so that if I have to run this project in another system I don't have to change path again and again.

Well if it is maven project just put your resources files under src/main/resources
and you can read them using this lines.
String path = Thread.currentThread().getContextClassLoader()
.getResource("yourFileName").getPath();
System.out.println(path);
Or even this way you can do it.
String pathOfTheFile = getServletContext().getResource("yourFile").getPath();
and don't forget to put the file under web-content or webapp folder

Find a resource both in .jar and eclipse with the same String computation

I want to get the path to a resource for ImageIO to read out a BufferedImage from some .png s.
While developing the project I use a relative path to "/bin/stuff/icons/image.png" , but this will definetly not work when I put everything together into a .jar file, so I need a way to get the path to these resources both while testing in eclipse and when later running it within a .jar .

After a lot of trying out both finding the file and getting the input stream to the file I came to the conclusion that this approach works every time:
InputStream in = ClassLoader.getSystemClassLoader().getResourceAsStream(path)
BufferedImage image = ImageIO.read(in)
Where path is
"projectName/resourceFolder/" + nameOfResource.stuff
as found in the src directory of the eclipse project.
E.g.
"myProject/images/icon.png"
When getting only the resource and then getting the path of the resource to link to a file, you will get FileNotFoundExceptions when using a .jar (but not while testing with eclipse, so one should be warned to think that his code works).
And - no - I don't save images in the bin/ - but they are copied to this directory and thus I find them there while testing. Now everything seems to be working.

Don't put anything under the bin directory in Eclipse: if you run a clean on the project it will be erased.
What you can do is to define a new source folder like resources, and put the image there. This way it will be automatically copied to the bin folder.
If you include the resources folder into the Jar, it will be available in both environments by using something like:
ImageIO.read( getClass().getResource("/image.png") )
PS: You can evade using a different resources folder but mixing the sources and images will quickly pollute your source folder.

cannot locate properties file in java path

My code cannot locate the .properties file where i have stored login information.
I have put the file in the src folder to make sure it compiles, and it does correctly.
below is the current location of the file and how i am trying to access it.
I have tried various different paths but no luck.

Change your code;
ResourceBundle bundle = ResourceBundle.getBundle("Selenium/readme");
to
ResourceBundle bundle = ResourceBundle.getBundle("readme");

You don't compile a .properties file, you use it as is.
If you use a FileInputStream it will use the working directory which is set in your Run configuration (most likely the top directory)
But you are loading it as a resource which means it must be in your class path. The simplest thing to do is to create a sub-directory for your configuration and add this to your programs class path.

Read properties file like:
ResourceBundle.getBundle("src/properties/readme.properties"); //Or simply "properties/readme.properties"
Put readme.properties under src/properties directory.

you can use this.getClass().getResourceAsStream("readme.properties");
for more information read:

I see that the .properties file is not inside the src folder. Also check the build path of your project.It will show you the src folders and the output folders location. Once you build the project using eclipse build project option, make sure your properties file is now available in the output folder.

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/