Clazz

Clazz contains class-loading and type-hierarchy helpers. Object construction is provided separately by NewInstance.

Loading classes

getClassByName(String) loads a class by its fully qualified name and throws RuntimeException if it cannot be found. The original ClassNotFoundException is retained as the cause. The typed overload also verifies assignability:

Class<CharSequence> type =
        Clazz.getClassByName("java.lang.String", CharSequence.class);

// Throws ClassCastException: String is not a Number.
Clazz.getClassByName("java.lang.String", Number.class);

Passing a null target type throws IllegalArgumentException.

Converting arguments to classes

args2class(Object[]) returns the runtime class of each argument. A null or empty array produces null. An individual null element causes IllegalArgumentException identifying its index; use an explicit Class<?>[] when a parameter value is null.

Class<?>[] types = Clazz.args2class(new Object[]{"text", 1});
// [String.class, Integer.class]

Inspecting interfaces and superclasses

getDeclaredInterface(Class<?>) returns every interface implemented by the class and its superclasses. Parent interfaces are traversed recursively. A Set<Class<?>> prevents duplicates in diamond-shaped interface graphs.

getAllSuperClass(Class<?>) returns the superclass chain, excluding the input class and Object. It is safe to call with an interface type and returns an empty array in that case.

Class<?>[] interfaces = Clazz.getDeclaredInterface(ArrayList.class);
Class<?>[] parents = Clazz.getAllSuperClass(ArrayList.class);

getClassByInterface(Type) delegates directly to Types.type2class(Type) instead of parsing the display value returned by Type.toString(). It therefore follows the same rules for classes, parameterized types, type variables, wildcards, and generic arrays. A type without one unique resolution causes IllegalArgumentException.

Both hierarchy methods reject a null class with IllegalArgumentException.