On 08/09/2020 14:16, Daniel Fuchs wrote:
Hi Jaikiran,
I expect it's an incorrect use of the API. AFAICS JarURLConnection
has always behaved like this.
Opening an inputstream requires an entry, (see
https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/util/jar/JarFile.html#getInputStream(java.util.zip.ZipEntry)
and as specified, the entry in that JarURLConnection is null.
You can still obtain the JarFile or read the manifest though from
the JarURLConnection though.
That said, maybe the API should be clarified to make it
explicit that an exception will be thrown if getInputStream()
is called on a connection that refers to a jar file (and whose
entry/entry name is null).
I agree the javadoc could be a bit clearer as
jar:file:/tmp/some-jar.jar!/ is ambiguous. In some contexts it is a URL
to the "whole JAR file" as JarURLconnection says. In the other contexts,
including the zip file system provider, it is the URL to the top-most
directory in the JAR file, i.e. zipfs.getPath("/").toUri().
-Alan
