In Java, how can I construct a File from a resource?

Question

File takes String and URI in its constructors.

getClass().getResource(...) returns URL and getResourceAsStream(...) returns InputStream. Is there a way to construct a File from a resource?

Answer 1

You can't. At least not in the standard case where the resource is inside a Jar. Java File Objects must point to actual file system objects (files and folders), whereas a resource is an entry in a Jar File. Trying to construct a File from a Jar resource URI will result in an exception:

java.lang.IllegalArgumentException: URI is not hierarchical

Answer 2

Is there a way to construct a File from a resource?

Strictly speaking, no. But if you really need a File (to pass to an API), then you can create a temporary file and write the InputStream to that.