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

[mandy chung]

On 11/3/17 1:06 AM, Christoph Dreis wrote:
>
> Thanks - I updated both as you suggested to use Class::getPackageName. Please find the updated patch below.

I have created https://bugs.openjdk.java.net/browse/JDK-8190733 for this 
patch.

> There is also a public static VerifyAccess::getPackageName which seems to be not working with arrays at all and as far as I can see is at least not used inside the JDK itself.
> Should this be deprecated maybe in favor of Class.getPackageName() or also adjusted to use it (which would mean different return values than before as you already noted)?

VerifyAccess::getPackageName is unused in jdk8u-dev neither.  So I think it can be removed.  No deprecation is needed since this is JDK internal API and I hardly think anyone is depending on it.

Mandy

> Cheers,
> Christoph
>
> ====== PATCH =======
> diff -r 438e0c9f2f17 src/java.base/share/classes/java/io/ObjectInputFilter.java
> --- a/src/java.base/share/classes/java/io/ObjectInputFilter.java	Mon Oct 30 17:49:33 2017 -0700
> +++ b/src/java.base/share/classes/java/io/ObjectInputFilter.java	Fri Nov 03 08:38:15 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);
>               }
>   
>               /**
>
> diff -r 438e0c9f2f17 src/java.base/share/classes/java/io/ObjectStreamClass.java
> --- a/src/java.base/share/classes/java/io/ObjectStreamClass.java	Mon Oct 30 17:49:33 2017 -0700
> +++ b/src/java.base/share/classes/java/io/ObjectStreamClass.java	Fri Nov 03 08:38:15 2017 +0100
> @@ -1587,11 +1587,7 @@
>        * Returns package name of given class.
>        */
>       private static String getPackageName(Class<?> cl) {
> -        String s = cl.getName();
> -        int i = s.lastIndexOf('[');
> -        i = (i < 0) ? 0 : i + 2;
> -        int j = s.lastIndexOf('.');
> -        return (i < j) ? s.substring(i, j) : "";
> +        return cl.getPackageName();
>       }
>   
>       /**
>
> diff -r 438e0c9f2f17 src/java.base/share/classes/java/lang/ClassLoader.java
> --- a/src/java.base/share/classes/java/lang/ClassLoader.java	Mon Oct 30 17:49:33 2017 -0700
> +++ b/src/java.base/share/classes/java/lang/ClassLoader.java	Fri Nov 03 08:38:15 2017 +0100
> @@ -672,12 +672,11 @@
>                   return;
>               }
>   
> -            final String name = cls.getName();
> -            final int i = name.lastIndexOf('.');
> -            if (i != -1) {
> +            final String packageName = cls.getPackageName();
> +            if (!packageName.isEmpty()) {
>                   AccessController.doPrivileged(new PrivilegedAction<>() {
>                       public Void run() {
> -                        sm.checkPackageAccess(name.substring(0, i));
> +                        sm.checkPackageAccess(packageName);
>                           return null;
>                       }
>                   }, new AccessControlContext(new ProtectionDomain[] {pd}));
>
> diff -r 438e0c9f2f17 src/java.base/share/classes/java/lang/reflect/Proxy.java
> --- a/src/java.base/share/classes/java/lang/reflect/Proxy.java	Mon Oct 30 17:49:33 2017 -0700
> +++ b/src/java.base/share/classes/java/lang/reflect/Proxy.java	Fri Nov 03 08:38:15 2017 +0100
> @@ -1034,11 +1034,8 @@
>   
>                   // do permission check if the caller is in a different runtime package
>                   // of the proxy class
> -                int n = proxyClass.getName().lastIndexOf('.');
> -                String pkg = (n == -1) ? "" : proxyClass.getName().substring(0, n);
> -
> -                n = caller.getName().lastIndexOf('.');
> -                String callerPkg = (n == -1) ? "" : caller.getName().substring(0, n);
> +                String pkg = proxyClass.getPackageName();
> +                String callerPkg = caller.getPackageName();
>   
>                   if (pcl != ccl || !pkg.equals(callerPkg)) {
>                       sm.checkPermission(new ReflectPermission("newProxyInPackage." + pkg));
>
>