8026176: Enhance document printing

Reviewed-by: bae, jgodinez

src/share/classes/javax/print/SimpleDoc.java

@@ -91,7 +91,10 @@ public final class SimpleDoc implements Doc {
 
        Class repClass = null;
        try {
-            repClass = Class.forName(flavor.getRepresentationClassName());
+            String className = flavor.getRepresentationClassName();
+            sun.reflect.misc.ReflectUtil.checkPackageAccess(className);
+            repClass = Class.forName(className, false,
+                              Thread.currentThread().getContextClassLoader());
        } catch (Throwable e) {
            throw new IllegalArgumentException("unknown representation class");
        }