Parent-first loading has been the standard mechanism in the JDK
class loader, at least since Java 1.2 introduced hierarchical classloaders.
- The primary reason for this is safety -- parent-first
- makes it impossible for malicious code to trick the JVM into
- replacing a core class (say, java.security.SecurityManager) with a
- class of the same name loaded from a child classloader.
Child-first classloading has the advantage of helping to improve isolation