JAR URLs have the following syntax

 jar:<jar-file-uri>!/<jar-entry>

 EXAMPLE: jar:http://www.big.com/blue.jar!/ocean.html

 The nsIURL methods operate on the <jar-entry> part of the spec.
[scriptable, uuid(b0922a89-f87b-4cb5-8612-305a285fcca7)]
interface nsIJARURI : nsIURL

Attributes

 Returns the entry specified for this JAR URI (e.g., "ocean.html").  This
 value may contain %-escaped byte sequences.
attribute AUTF8String JAREntry 
 Returns the root URI (the one for the actual JAR file) for this JAR
 (e.g., http://www.big.com/blue.jar).
readonly attribute nsIURI JARFile

Methods

 Create a clone of the JAR URI with a new root URI (the URI for the
 actual JAR file).
nsIJARURI cloneWithJARFile(in nsIURI jarFile)