package reflectionZ;

import java.lang.reflect.Constructor;

import java.lang.reflect.Type;

public class Tzz02

{

    public static void main(String[] args) throws Exception

    {

        // getConstructors() / getConstructor(...)

        Class<?> clazz1 = Class.forName("reflectionZ.Cat");

        // 1、使用的是 默认的 构造函数

        Object obj01 = clazz1.newInstance();

        // 2、通过Class对象来得到构造函数

        Constructor<?> c1 = clazz1.getConstructor(Class.forName("java.lang.String"), int.class);

        Object obj0201 = c1.newInstance("小猫", 6); // 强转

        Constructor<?> c2 = clazz1.getConstructor(String[].class);

        String[] foods = {"鱼", "老鼠"};

        Object obj0202 = (Cat)c2.newInstance((Object)foods); // 对象数组foods会被打散

        if (obj01.getClass() == clazz1)

            System.out.println("obj01.getClass() == clazz1");

        else

            System.out.println("obj01.getClass() != clazz1");

        if (obj0201.getClass() == clazz1)

            System.out.println("obj01.getClass() == clazz1");

        else

            System.out.println("obj01.getClass() != clazz1");

        if (obj0202.getClass() == clazz1)

            System.out.println("obj01.getClass() == clazz1");

        else

            System.out.println("obj01.getClass() != clazz1");

    // *** *** ***

        System.out.println();

        int iIdx = 0;

        Constructor<?>[] constructors = clazz1.getConstructors();

        for (Constructor<?> constructor :constructors)

        {

            Type[] types = constructor.getGenericParameterTypes();

            if (types.length == 0)

                System.out.println("["+iIdx+"] ==> 无参构造函数");

            else

            {

                System.out.println("["+iIdx+"] ==> "+types.length+"个参数的 构造函数，参数的类型分别为:");

                for (Type type : types)

                {

                    System.out.println(type);

                }

            }

            System.out.println();

            iIdx ++;

        }

    }

}

class Cat

{

    public Cat()

    {}

    public Cat(String _strName, int _iAge)

    {

        System.out.println("Cat --> _strName : "+_strName+" , _iAge : "+_iAge);

    }

    public Cat(String[] _foods)

    {

        if (_foods == null)

            System.out.println("Cat --> _foods is null .");

        else

        {

            for (int i=0; i<_foods.length; i++)

                System.out.println("Cat -->  _foods["+i+"] : "+_foods[i]);

        }

    }

}

Cat --> _strName : 小猫 , _iAge : 6

Cat -->  _foods[0] : 鱼

Cat -->  _foods[1] : 老鼠

obj01.getClass() == clazz1

obj01.getClass() == clazz1

obj01.getClass() == clazz1

[0] ==> 无参构造函数

[1] ==> 2个参数的 构造函数，参数的类型分别为:

class java.lang.String

int

[2] ==> 1个参数的 构造函数，参数的类型分别为:

class [Ljava.lang.String;