import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

class Cat {
    //私有属性name
    private String name = "bit";
    //公有属性age
    public int age = 18;

    //不带参数的构造方法
    public Cat() {
        System.out.println("Student()");
    }

    private Cat(String name, int age) {
        this.name = name;
        this.age = age;
        System.out.println("Student(String,name)");
    }

    private void eat() {
        System.out.println("i am eat");
    }

    public void sleep() {
        System.out.println("i am pig");
    }

    private void function(String str) {
        System.out.println(str);
    }


    @Override
    public String toString() {
        return "Student{" +
                "name='" + name + '\'' +
                ", age=" + age +
                '}';
    }
}

public class TestReflection {


    //创建对象
    public static void reflectNewInstanse() {
        Class<?> c1=null;

        try {
            c1=Class.forName("练习.Cat");

            //Student student=new Student();

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


        Class<?> c2= Cat.class;

        Cat student=new Cat();
        Class<?> c3=student.getClass();

        //System.out.println(c1.equals(c2));
    }

    // 反射私有的构造方法 屏蔽内容为获得公有的构造方法
    public static void reflectPrivateConstrcter() {

        Class<?> c1=null;

        try {
            c1=Class.forName("练习.Cat");

            Cat student=(Cat) c1.newInstance();

            //获得private方法权限
            Constructor<?> constructor= c1.getDeclaredConstructor(String.class,int.class);
            constructor.setAccessible(true);

            //可以用方法调用了
            Cat student1=(Cat) constructor.newInstance("yuanye",18);
            System.out.println(student1);

        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (InstantiationException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (NoSuchMethodException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }
    }


    // 反射私有属性
    public static void reflectPrivateField() {

        Class<?> c1=null;
        try {
            c1=Class.forName("练习.Cat");
            //开权限
            Field field=c1.getDeclaredField("name");
            field.setAccessible(true);


            Cat student=(Cat) c1.newInstance();
            //field.set(student,"yuanye");//要改里面的参数就用set方法改
            System.out.println(student);

            String str=(String)field.get(student);
            System.out.println(str);



        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (InstantiationException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (NoSuchFieldException e) {
            e.printStackTrace();
        }


    }
    // 反射私有方法
    public static void reflectPriveatMethod(){
        Class<?> c1=null;

        try {
            c1=Class.forName("练习.Cat");
            Method method=c1.getDeclaredMethod("function", String.class);
            method.setAccessible(true);

            Cat student=(Cat)c1.newInstance();
            System.out.println(student);

            method.invoke(student,"func是一个参数");

        } catch (ClassNotFoundException | NoSuchMethodException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        } catch (InstantiationException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }
    }


    public static void main(String[] args) {
        reflectNewInstanse();
        reflectPrivateConstrcter();
        System.out.println("===========================");
        reflectPrivateField();
        reflectPriveatMethod();

    }






    public static void main1(String[] args) {

        Class<?> c1=null;
        //1、获得class的对象的student类
        try {
            c1=Class.forName("练习.Cat");//用的最多的

            //Student student=new Student();
            Cat student=(Cat) c1.newInstance();//!!!!!!!!!

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

        //2、获得class的对象的student类
        Class<?> c2= Cat.class;

        //3.获得class的对象的student类
        Cat student=new Cat();
        Class<?> c3=student.getClass();

        System.out.println(c1.equals(c2));
        System.out.println(c1==c3);
        System.out.println(c2==c3);


    }



    // 反射私有的构造方法 屏蔽内容为获得公有的构造方法
    public static void reflectPrivateConstructor() throws NoSuchMethodException {

        Class<?> c1=null;
        try {
            c1=Class.forName("练习.Cat");

            //Student student=new Student();
            Cat student=(Cat) c1.newInstance();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (InstantiationException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }


        Constructor<?> constructor= c1.getDeclaredConstructor(String.class,int.class);



    }
}