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

[mandy chung]

On 11/2/17 5:55 PM, Christoph Dreis wrote:
Hey,

I noticed two places in the codebase that could call JDK 9's new method
Class.getPackageName().

It's good to see JDK code be updated to use Class::getPackageName. One 
thing to pay attention is that Class.getPackageName() returns 
"java.lang" for primitive type and void.  Your patch fixing 
ObjectStreamClass::getPackageName and Proxy::checkNewProxyPermission 
look fine.

There are other places that can be converted.  Do you mind updating 
java.io.ObjectInputFilter::matchesPackage and 
ClassLoader::checkPackageAccess?   I may miss there are other places in 
java.base.

I can sponsor this once you have an updated patch.

Mandy

Would be happy if this is sponsored in case the patch is correct.

Cheers,
Christoph

====== PATCH =======
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 01:47:04 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/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
01:47:04 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));