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Java FileNotFoundException when trying to read txt file from resources folder

I'm trying to read a text file located in src/main/resources/test/file.txt. I'm trying to get the path of the file using String path = getClass().getResource("/text/file.txt").getFile(); but when I try to read it I get a FileNotFoundException. I tried putting many different paths, all of which failed. How can I go about doing this?

The idea of putting something into the src/main/resources tree is that it will be copied into the JAR file that you build from your project. It will then be available to your application via the Class methods getResource(String) and getResourceAsStream(String) methods.
When you are running in your application in the development environment, it is certainly possible to use FileInputStream etcetera to access the resource. But this won't work in production. In production, the resources will then be inside your app's JAR file. FileInputStream cannot open a JAR file and its contents by name.
When you do this:
getClass().getResource("/text/file.txt");
you get a URL for the resource, which will look something like this:
jar:file:/path/to/your.jar!/text/file.txt"
It is not possible to turn that into a pathname the FileInputStream will understand. Whatever you try will give you a FileNotFoundException ... or something that is not the resource you want to read.
So what to do?
You have a few options, depending on your application's requirements.
You can use getResourceAsStream and use the resulting input stream directly.
You can copy the contents of getResourceAsStream to a temporary file, and then use the pathname of the temporary file.
You can create an application specific directory (e.g. in the user's home directory) and extract the file you need from the JAR into the directory. You might do this the first time the application runs.
You could open the JAR file as a JarFile and use that API to open an InputStream for the resource. But this assumes that that the resources are in a JAR ... and on some platforms (e.g. Windows) you may encounter problems with file locking. (And it would be a bad idea to attempt to update the resource in the JAR.)

Try giving complete path of the file from the disk.
C:\Users\MyUser\Desktop\file name with extension

How to read a file from a different folder than the project

I'm trying to read a txt file that is in a folder called "levels". The class where I'm using the Scanner is in src/anotherPackageName, if that's relevant. When I execute:
Scanner s = new Scanner(new File("levels/level0")); //adding .txt doesn't fix
it throws an exception. I don't want to use an absolute path, but rather relative to the project if possible. This is my folder structure:
D:\OneDrive\Folder\AnotherFolder\ProjectName
ProjectName
src
packageOne
ClassWhereImUsingScanner
OtherClasses
(...)
levels
level0
level1
(...)

So in order to access a file you could do something like this:
FileReader sourceFile = new FileReader("levels/level0.txt");
BufferedReader inStream = new BufferedReader(sourceFile);
String Line = inStream.readLine();
Then, you can use a tokenizer depending on your data and how you want to store it.
You could see this example: http://www.mkyong.com/java/how-to-read-file-from-java-bufferedreader-example/

Bear in mind that in most Java code, the end state of the project is not run from the IDE, but rather from some production system (e.g. an app or a server). In that case, your development source code structure won't be available.
There are two main ways to read text files or other resources in Java: either you can find the path to the actual file, in which case you need to deal with possibly not running out of your development source tree, or else you need to find a way to bundle the text file into your project.
Most Java projects end up getting compiled into some kind of archive, either a JAR file or a WAR file (for web applications) or something like an Android APK. In most cases you can add your own text files into the project archive. (For example, in a Maven project, if you just put your text file in the src/main/resources folder it should be included in the compiled JAR.)
However, in this case, the text file is no longer a separate file on disk, but rather a blob of data inside an archive. You could unzip the archive to get an actual File object, but that's wasteful if all you actually need is to read the bytes.
Thus, the most common way that text files like this are read is by using the existing ClassLoader mechanism, which is what is reading the .class files from disk (or from an archive, or over the network, or whatever). The ClassLoader already knows how to load bytes that are "alongside" your compiled code, so you can just make use of that.
In your case, you should be able to do something like this:
Scanner scanner = new Scanner(
getClass().getResourceAsStream("/path/to/file.txt"));
In this case, the /path/to/file.txt path is relative to the path your class was loaded from. E.g. if your class is named my.package.Foo then the actual class bytes will be in a folder (either a filesystem folder or in a JAR file or something) named my/package/Foo.class -- in this case, the path/to/file.txt and my/package/Foo.class will be relative to the same root.
See the documentation on resources for more information.

Usually the path is relative to your execution, but it also depends on your project setup on eclipse, could you send more information about you directory structure?
Based on you structure try something like this:
Scanner s = new Scanner(new File("../levels/level0"));

Java & JTar - how to add a file inside a folder using JTar?

Windows - I am trying to create a new Tar file with with the JTar lib with the following inside...
MyTarFile.tar--|
|--MyFolder--|
|--MyFile.zip
I can create it with the folder and the zip file right in the root of MyTarFile but I don't know (and I looked around) how to create that folder AND have the zip file inside. I need to know what to use (the File object(s)) for the TarEntry(s) (is it one for folder and one for file...or one for both?) and what the InputStream should look like (I believe just a single one for the zip file but not sure). I am trying to create a file to mimic an existing format so I don't have the option of just losing that folder as the software that uses the file will be looking for it. I can add the zip file to the MyFolder folder on the actual file system (again, this is on Windows) before tarring or not...whatever works is fine.
I have tried full paths and relative paths (seems the InputStream MUST have a full path though) with no luck. Running out of ideas other than switching libraries (perhaps JTar doesn't support this).
Thanks!

Without seeing what you have already written, here is my best attempt at answering. I am unfamiliar with JTar, but after taking a look at the example on their main page, I wrote a quick test program that created a tar with one file in the root of the tar and one file in a directory in the tar, which I believe is what you are attempting to do. The code of interest to you is this:
TarEntry tarEntry = new TarEntry(new File("/Users/userGuy/Documents/students.xml"),"students.xml");
TarEntry otherTarEntry = new TarEntry(new File("/Users/userGuy/Documents/students2.xml"),"inner-dir/students2.xml");
Note that the second tar entry, otherTarEntry is instantiated with a relative path as the entryName argument in the TarEntry constructor. This is a poorly named argument, as it is technically the path of the file in the tar, not just the name.
With your example file names above, your code might look something like this:
TarEntry tarEntry = new TarEntry(new File("<path to file>"),"MyFolder/MyFile.zip");

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/

java.io.FileNotFoundException question

I have a text file text.txt located in the classes output root directory.
When I use new File("text.txt"), i received the java.io.FileNotFoundException.
My output structure is liking
com
mycompany
test.class
text.txt
Anything wrong and how to fix?

When you don't give an absolute location for a file it searches from where you launched the program (your working directory). So, launch your application in the same directory as that file or move the file to where ever you are launching from.
If you want to read a file relative to your classpath however, you need to do something like this...
reader = new BufferedReader(new InputStreamReader(
getClass().getClassLoader().getResourceAsStream("test.txt")));

It will use the current working directory. From the Java documentation (http://download.oracle.com/javase/1.4.2/docs/api/java/io/File.html#File%28java.lang.String%29):
By default the classes in the java.io package always resolve relative pathnames against the current user directory. This directory is named by the system property user.dir, and is typically the directory in which the Java virtual machine was invoked.

new File("text.txt") is relative to your working directory. You could use this.getClass().getResourceAsStream("text.txt") to load a file from the classpath.