CODEWITHSUNDEEP
javajar
harshit
harshit

Reputation: 7951

How to read a file from a java class, both are in the same jar

I have following structure in jar

myjar.jar -> com -> MYProgram.class

       -> file.txt

In MYProgram i am trying to do:

getClass().getResourceAsStream("../file.txt")

I am getting NullpointerException when i try to read the inputstream..

Where is it going wrong ?

Upvotes: 2

Views: 1171

Answers (2)

Mark Peters
Mark Peters

Reputation: 81074

Try the absolute path:

getClass().getResourceAsStream("/file.txt")

The Javadoc for getResourceAsStream says:

  • If the name begins with a '/' ('\u002f'), then the absolute name of the resource is the portion of the name following the '/'.

  • Otherwise, the absolute name is of the following form:

        modified_package_name/name

    Where the modified_package_name is the package name of this object with '/' substituted for '.' ('\u002e').

This would turn your path into this absolute path:

/com/../file.txt

I don't think the .. notation is respected. It literally looks for the above absolute path.

Upvotes: 5

Jon Skeet
Jon Skeet

Reputation: 1500065

Either use

getClass().getResourceAsStream("/file.txt")

or

getClass().getClassLoader().getResourceAsStream("file.txt")

(ClassLoader.getResourceAsStream always takes an "absolute" resource name.)

I don't believe navigating up the "directory hierarchy" works in getResourceAsStream - the path either has to be relative to the given class but without navigating back up the tree, or it has to be absolute to start with.

Upvotes: 7

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