Playing with reflection.

PersonTest.java

import java.io.IOException;
import java.lang.reflect.*;

/**
 * Created by melisa on 31/05/2017.
 */
class Person {
    private String privateName;
    public String publicName;
    public Person friend;
    public Person(String privateName , String publicName)
    {
        this.privateName = privateName;
        this.publicName = publicName;
    }
    public void beFriend(Person friend)
    {
        this.friend = friend;
    }
    private void unfriend()
    {
        if(friend!=null)
            friend = null;
    }
    public void exceptional() throws Exception
    {
        throw new IOException();
    }
    public String toString()
    {
        return new String(publicName + privateName);
    }
}

public class PersonTest
{
    public static void main(String [] args)
    {
        Class c1 = Person.class;
        System.out.println("Class       :" + c1);
        System.out.println("Class Name  :" + c1.getName());
        System.out.println("Class Type  :" + c1.getTypeName());
        System.out.println("Super Class :" + c1.getSuperclass());

        Method [] methods = c1.getMethods();
        System.out.println("GetMethods");
        for(Method m : methods)
        {   System.out.println(m);
            System.out.println(m.getName());
            System.out.println(m.getModifiers());
            System.out.println(m.getDeclaringClass());
            System.out.println("----");
        }
        System.out.println();

        Method [] declaredMethods = c1.getDeclaredMethods();
        System.out.println("GetDeclaredMethods");
        for(Method m : declaredMethods)
        {   System.out.println(m);
            System.out.println(m.getName());
            System.out.println(m.getModifiers());
            System.out.println(m.getDeclaringClass());
            System.out.println("----");
        }
        System.out.println();

        Field [] fields = c1.getFields();
        System.out.println("GetFields");
        for(Field m : fields)
        {   System.out.println(m);
            System.out.println(m.getModifiers());
            System.out.println(m.getType());
        }
        System.out.println();

        Field [] declaredFields = c1.getDeclaredFields();
        System.out.println("GetDeclaredFields");
        for(Field m : declaredFields)
            System.out.println(m);
        System.out.println();

        Person[] personList = new Person[2];
        personList[0] = new Person("Christ", "Jesus");
        personList[1] = new Person("St.", "Joseph");
        for(Person p : personList)
            System.out.println(p);
        System.out.println();

        Person[] personList2= (Person[]) Array.newInstance(c1,5);
        personList2[0] = new Person("Bach", "Sebastian");
        personList2[1] = new Person("Mozart", "Amadeus");
        personList2[2] = new Person("Bethooven", "Ludwig Van");
        personList2[3] = new Person("Brahms", "Johannes");
        Array.set(personList2,4,new Person("Vivaldi","Antonio"));

        for(Person p : personList2)
            System.out.println(p);
        System.out.println();

        Class[] paramTypes = new Class[]{String.class,String.class};
        try {
            //Throws Exception If the constructor isn't public.
            Constructor cons = c1.getConstructor(paramTypes);
            Object[] arguments = new Object[] {"Myung", "John"};
            Person p = (Person) cons.newInstance(arguments);
            System.out.println("Created Object With Reflection: " + p );

            Method m = p.getClass().getDeclaredMethod("exceptional");
            System.out.println(m.getName());
            m.invoke(p);
        } catch (NoSuchMethodException | IllegalAccessException | InstantiationException e) {
            e.printStackTrace();
        }
        catch (InvocationTargetException e)
        {
            System.out.println(e.getCause());
        }




    }
}