How to use Reflection in Java

import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
public class ReflectionExample {

  public static void main(String[] args) {
    try {
      // Creates an object of type Class which contains the information of 
      // the class String
      Class cl = Class.forName("java.lang.String");

      // getDeclaredFields() returns all the constructors of the class.
      Constructor cnst[] = cl.getConstructors();

      // getFields() returns all the declared fields of the class.
      Field fld[] = cl.getDeclaredFields();

      // getMethods() returns all the declared methods of the class.
      Method mtd[] = cl.getMethods();
      System.out.println("Name of the Constructors of the String class");

      for (int i = 0; i < cnst.length; i++) {
        System.out.println(cnst[i].getName());
      }

      System.out.println("Name of the Declared fields");

      for (int i = 0; i < fld.length; i++) {
        System.out.println(fld[i].getName());
      }

      System.out.println("Name of the Methods");

      for (int i = 0; i < mtd.length; i++) {
        System.out.println(mtd[i].getName());
      }

    } catch (ClassNotFoundException e) {
      e.printStackTrace();
    }
  }

}