Points To Remember
  • We can get the constructors declared in a class using Reflection API.
  • Constructor class is present in java.lang.reflect.Constructor class.
  • The getDeclaredConstructors() method will return an array of Constructors in a class.
Program : Get all constructors declared in a class
import java.lang.reflect.Constructor;


class SampleClass{

String s1 = "Class variable";
int a = 123;

public SampleClass(){
System.out.println("SampleClass Default Constructor");
}

public SampleClass(String str){
System.out.println("SampleClass Overloaded Constructor");
}

public void show(){
System.out.println("SampleClass Show Method");
}

public void print(){
System.out.println("SampleClass Print Method");
}

}

class Test{

public static void main(String args[]){
Test obj = new Test();
try{
Class clazz = Class.forName("SampleClass");
Constructor cc[] = obj.getConstructors(clazz);
for(Constructor constructor : cc){
System.out.println(constructor);
}
}catch(Exception e){
e.printStackTrace();
}

}

public Constructor[] getConstructors(Class clazz){
return clazz.getDeclaredConstructors();
}

}
public SampleClass()
public SampleClass(java.lang.String)
The above example shows how we can get all the constructors that are declared within a class. We first get the Class of the class and then call the getDeclaredConstructors() methods to get an array of all declared constructors.