getDeclaredConstructors

DeclaredConstructors is a Java Reflection API feature that allows programmatic access to the constructors of a class. It is part of the java.lang.reflect package and specifically found within the java.lang.Class class. When you obtain a Class object for a given class, you can then call its getDeclaredConstructors() method. This method returns an array of Constructor objects, each representing a constructor declared by that class.

The returned Constructor objects provide detailed information about each constructor, including its modifiers (like public, private, protected), parameter types, and any exceptions it declares. This enables developers to inspect, and in some cases, even invoke constructors dynamically at runtime. This is particularly useful in frameworks, libraries, and applications that need to create objects without knowing the exact class type at compile time, such as serialization frameworks, dependency injection containers, or unit testing tools.

It's important to distinguish getDeclaredConstructors() from getConstructors(). While getDeclaredConstructors() returns all constructors declared directly by the class (regardless of their access modifier), getConstructors() returns only the public constructors, including those inherited from superclasses. Therefore, getDeclaredConstructors() provides a more comprehensive view of a class's construction capabilities.