The implementation of java.net.JarURLConnection has a private String, `entryName`, that is used to hold the optional jar file entry name. If the JAR file URL corresponding to the JarURLConnection points to a JAR file and not a JAR file entry, then `entryName` will be `null` ( which should be ok ).
The default implementation of JarURLConnection::getJarEntry should only invoke `getJarEntry(entryName)` if the name is non-null. ( This is not an issue in the built-in JarURLConnection handler implementation, as it already correctly handles a null `entryName` ) https://cr.openjdk.java.net/~chegar/8225037/webrev.00/ -Chris.
