Why does getResource return null

Question

I'm trying to access a file in my project. But getResource method returns null.

This is how my project looks like:

Thread.currentThread().getContextClassLoader().getResource("assets/xxx.png"); //returns null

And how project folder in eclipse workspace looks like:

Why? I want to access files in my assets folder?

Edit I created a jar file and this is content of the jar:

Solved

First of all, I've a lot of image files so I want to organize all them in a folder. I put the assets folder in src directory and finally I was able to access the files.

this.getClass().getClassLoader().getResource("assets/xxx.png");

Schoolmistress

You can't access the assert folder unless otherwise you have bundled it in your jar. Can you extract a jar and show the content of so that we can help you. – Anna

Is asset folder defined as source folder? – Fountainhead

@Fountainhead yes, defined as source folder – Schoolmistress

@Anna I did it.. I edited my post, can you take a look? – Schoolmistress

assets/ should not be in the path. It's an outside (not in the src) folder in the build path, which just means its contents are put into the root, without the directory. See here – Durwood

Answer 1

There are lot of ways to add a resource to the jar file, you can put it in src, add as a resource if you use maven, ant etc... If you able to bundle whole directory then you should be able to use your original piece of code. With the current structure you can use following piece of code.

Thread.currentThread().getContextClassLoader().getResource("/xxx.png"). 

Anna

If I simply add all files to bin directory I can access. But there are many files in my project and I want to organize them in a directory. So I want to put all files in a folder and access them from this directory. – Schoolmistress

Put the whole asserts directory in src (source) folder. Eclipse will bundle that for you. – Anna

@Anna - Your code seems to get a relative path. What is it relative to and how can I find out the root ? – Heterocercal

Answer 2

For someone struggling as me. For Maven just run mvn clean install. After that Thread.currentThread().getContextClassLoader().getResource() should work.

Priscella

Answer 3

Try using / prefixing.

Thread.currentThread().getContextClassLoader().getResourceAsStream("/xxx.png")

Supererogate

as per your jar structure i can see that image file in root. i updated my answer try once again. Thanks – Supererogate

try using getResourceAsStream, and change your class to take Inputstream instead of File. – Supererogate

Answer 4

Is there a reason you're using the the class loader of the current class? Something like this.getClass().getClassLoader().getResource("/xxx.png") should be more reliable.

Thorin

Answer 5

Use the following code, it should work.

YOUR_CLASS_HERE.class.getClass().getResource( "/xxx.png" );

e.g. Signin.class.getClass().getResource( "/xxx.png" );

Shamus

Answer 6

Either Approach will work. its just Filepath issue.

• Your Jar Structure shows no "asset" Folder
  xxx.png file is directly in Jar File.
  

Try to remove "assets" from below line of code.

Thread.currentThread().getContextClassLoader().getResource("assets/xxx.png"); //returns null

• Also, if you want to use "assets" folder in ur classpath, please ensure that your jar contains "assets" folder.

Lovesick