Loading a file from dependency jar inside maven junit

Question

I'm using maven 2.1.0 and have a project with multiple modules. Example modules:

• spr-resources
• spr-common

spr-common has a dependency on spr-resources

spr-resources contains only files, no classes.

spr-common has a junit in which needs to load a file from spr-resources jar.

I used:

String fileName = getClass().getResource("/jaskeyfile.3DES").getFile();
is = getClass().getClassLoader().getResourceAsStream(fileName);
is.read(data);

And this works when I run the test in IntelliJ, but when I do mvn test, it fails with NullPointerException when I try to do read() on it.

Why is this happening? It should read a file from dependency just fine.

Also, pom.xml in spr-common has dependency on spr-resources (tried both with scope test and without it)

EDIT: I tried also

getClass().getClassLoader().getResourceAsStream("/jaskeyfile.3DES");

with no luck.

EDIT2: The given file exists in the resulting jar, so I guess it should be accessible.

Answer 1

Check everything carefully

Here's a list to work through:

1. The file jaskeyfile.3DES is located in src/main/resources within the spr-resources module
2. Your local repository contains the latest version of spr-resources-xyz-SNAPSHOT.jar (or you've released it/versioned it directly) and you've definitely used mvn clean install on it
3. The spr-common module is referencing the correct (named) version of spr-resources-xyzjar (scope of compile will be seen on both test and compile classpaths)

If all the above are true then your getClass().getResourceAsStream("/jaskeyfile.3DES") invocation should work. I use this structure all the time in my projects so you're not asking for the moon or anything here.

Answer 2

I believe the issue may be with the leading slash. I think both of these should work:

• getClass().getResourceAsStream("/jaskeyfile.3DES")
• getClass().getClassLoader().getResourceAsStream("jaskeyfile.3DES")

Class.getResourceAsStream() takes a path relative to the class's package directory so it accepts the leading slash.

ClassLoader.getResourceAsStream() takes an absolute path already so it doesn't accept the leading slash.