[Patch][JDK10] Use Class.getPackageName() where possible

[mandy chung]

On 11/7/17 6:48 AM, Christoph Dreis wrote:
> ======= PATCH =======
> diff -r 67aa34b019e1 src/java.base/share/classes/java/io/ObjectInputFilter.java
> --- a/src/java.base/share/classes/java/io/ObjectInputFilter.java	Mon Nov 06 17:48:00 2017 -0800
> +++ b/src/java.base/share/classes/java/io/ObjectInputFilter.java	Tue Nov 07 15:44:36 2017 +0100
> @@ -656,8 +656,8 @@
>                * otherwise {@code false}
>                */
>               private static boolean matchesPackage(Class<?> c, String pkg) {
> -                String n = c.getName();
> -                return n.startsWith(pkg) && n.lastIndexOf('.') == pkg.length() - 1;
> +                String n = c.getPackageName();
> +                return n.length() == pkg.length() - 1 && n.startsWith(pkg);
>               }
>   

This is correct but we could simplify this.  We can modify the callers 
to drop a trailing "." from the pkg parameter.  I took the liberty to 
revise it a little.

http://cr.openjdk.java.net/~mchung/jdk10/webrevs/8190733/webrev.00/

Roger - can you take a look at the change in ObjectInputFilter?

Mandy