Does Java's "Class.forName" scan all class names from all jars?

Question

On compile or run, we usually have a lot of class/jar dependencies, and the database driver's jar is just one of them. So, does

Class.forName(X)

have to scan all these .class/.jar file names to locate proper driver class named X? If not, does Class.forName has any rule/algorithm to find particular class?

Answer 1

It delegates to the ClassLoader of the calling class. In most cases the answer is yes but there are ClassLoader implementations with more sophisticated rules e.g. OSGI which uses dynamic modules or JEE Server Application Classloading.

public static Class<?> forName(String className) throws ClassNotFoundException {
  Class<?> caller = Reflection.getCallerClass();
  return forName0(className, true, ClassLoader.getClassLoader(caller), caller);
}