Java创建对象的方式【仅代码记录】

package com.zibo.java.february.fourth;

public class CatTest {
    public static void main(String[] args) throws ClassNotFoundException, IllegalAccessException, InstantiationException {
        /*
         * 创建对象的三种方式：
         * 1、通过new关键字创建；
         * 2、通过Class.forName(String ClassName)和Class.newInstance()创建；
         * 3、通过Object.class和Class.newInstance()创建；
         */
        // 1、通过new关键字创建；
        Cat cat1 = new Cat();
        cat1.setName("喵咪");
        cat1.setAge(12);
        System.out.println(cat1);

        // 2、通过Class.forName(String ClassName)和Class.newInstance()创建；
        Class<?> aClass = Class.forName("com.zibo.java.february.fourth.Cat");
        Object instance = aClass.newInstance();
        if(instance instanceof Cat){
            Cat cat2 = (Cat)instance;
            cat2.setName("小喵");
            cat2.setAge(6);
            System.out.println(cat2);
        }

        // 3、通过Object.class和Class.newInstance()创建；
        Class<Cat> catClass = Cat.class;
        Cat cat3 = catClass.newInstance();
        cat3.setName("大喵");
        cat3.setAge(9);
        System.out.println(cat3);
    }
}
class Cat{
    private String name;
    private int age;

    public Cat() {
    }

    public void setName(String name) {
        this.name = name;
    }

    public void setAge(int age) {
        this.age = age;
    }

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