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

[Bernd Eckenfels]

The private static helper in ObjectStreamClass became a oneliner and can be removed and the callsites can transform from getPackageName(c) to c.getPackageName().

Gruss
Bernd
--
http://bernd.eckenfels.net
_____________________________
From: mandy chung <mandy.chung at oracle.com<mailto:mandy.chung at oracle.com>>
Sent: Samstag, November 4, 2017 1:12 AM
Subject: Re: [Patch][JDK10] Use Class.getPackageName() where possible
To: Christoph Dreis <christoph.dreis at freenet.de<mailto:christoph.dreis at freenet.de>>, 'Core-Libs-Dev' <core-libs-dev at openjdk.java.net<mailto:core-libs-dev at openjdk.java.net>>




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));
>
>