8279242: Reflection newInstance() error message when constructor has no access modifiers could use improvement

Reviewed-by: iris, dholmes, mchung

Author: jddarcy

src/java.base/share/classes/jdk/internal/reflect/Reflection.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2022, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -379,11 +379,8 @@ public static IllegalAccessException newIllegalAccessException(Class<?> currentC
 
         String msg = currentClass + currentSuffix + " cannot access ";
         if (m2.isExported(memberPackageName, m1)) {
-
             // module access okay so include the modifiers in the message
-            msg += "a member of " + memberClass + memberSuffix +
-                    " with modifiers \"" + Modifier.toString(modifiers) + "\"";
-
+            msg += "a member of " + memberClass + memberSuffix + msgSuffix(modifiers);
         } else {
             // module access failed
             msg += memberClass + memberSuffix+ " because "
@@ -410,11 +407,8 @@ private static IllegalAccessException newIllegalAccessException(Class<?> memberC
 
         String msg = "JNI attached native thread (null caller frame) cannot access ";
         if (m2.isExported(memberPackageName)) {
-
             // module access okay so include the modifiers in the message
-            msg += "a member of " + memberClass + memberSuffix +
-                " with modifiers \"" + Modifier.toString(modifiers) + "\"";
-
+            msg += "a member of " + memberClass + memberSuffix + msgSuffix(modifiers);
         } else {
             // module access failed
             msg += memberClass + memberSuffix+ " because "
@@ -424,6 +418,16 @@ private static IllegalAccessException newIllegalAccessException(Class<?> memberC
         return new IllegalAccessException(msg);
     }
 
+    private static String msgSuffix(int modifiers) {
+        boolean packageAccess =
+            ((Modifier.PRIVATE |
+              Modifier.PROTECTED |
+              Modifier.PUBLIC) & modifiers) == 0;
+        return packageAccess ?
+            " with package access" :
+            " with modifiers \"" + Modifier.toString(modifiers) + "\"";
+    }
+
     /**
      * Returns true if {@code currentClass} and {@code memberClass}
      * are nestmates - that is, if they have the same nesthost as