Java枚举类、注解：自定义枚举类、enum、Enum类、Annotation

package com.atguigu.java;

import org.junit.Test;


public class SeasonTest {
    @Test
    public void test(){
        Season spring = Season.SPRING;

        System.out.println(spring);
        System.out.println(spring.getSeasonName() + spring.getSeasonDesc());

    }
}
//自定义枚举类
class Season{
    //1.声明Season对象的属性:用private final来修饰：
    private final String seasonName;
    private final String seasonDesc;
    //2.私有化构造器（外界不能再多造了）
    private Season(String seasonName,String seasonDesc){
        this.seasonName = seasonName;
        this.seasonDesc = seasonDesc;
    }
    //3.提供当前枚举类的多个对象：声明为public static final
    public static final Season SPRING = new Season("春天","春暖花开");
    public static final Season SUMMER = new Season("夏天","夏日炎炎");
    public static final Season AUTUMN = new Season("秋天","秋高气爽");
    public static final Season WINTER = new Season("冬天","寒风刺骨");
    //4.其他诉求1：获取枚举类的属性

    public String getSeasonName() {
        return seasonName;
    }

    public String getSeasonDesc() {
        return seasonDesc;
    }
    //4.其他诉求2：提供toString()方法：
    @Override
    public String toString() {
        return "Season{" +
                "seasonName='" + seasonName + ''' +
                ", seasonDesc='" + seasonDesc + ''' +
                '}';
    }
}

package com.atguigu.java;

import java.util.Arrays;


public class SeasonTest1 {
    public static void main(String[] args) {
        Season1 summer = Season1.SUMMER;
        //toString()方法
        System.out.println(summer.toString());
        System.out.println(Season1.class.getSuperclass());

        //values()方法:返回一个数组
        Season1[] values = Season1.values();
        System.out.println(Arrays.toString(values));

        System.out.println("*******************");

        Thread.State[] states = Thread.State.values();
        for(int i = 0;i < states.length;i++){
            System.out.println(states[i]);
        }

        //valueOf(String objName):根据名字找到对象
        //如果没有objName
        Season1 winter = Season1.valueOf("WINTER");
        System.out.println(winter);
        winter.show();


    }
}

interface Info{
    public abstract void show();
}



//使用enum定义枚举类
enum Season1 implements Info{
    //3.最前面直接提供当前枚举类的多个对象，多个对象之间用逗号隔开，末尾的对象分号结束。
    SPRING ("春天","春暖花开"){
        @Override
        public void show() {
            System.out.println("这是一个"春天","春暖花开"");
        }
    },
    SUMMER ("夏天","夏日炎炎") {
        @Override
        public void show() {
            System.out.println("这是一个"夏天","夏日炎炎"");
        }
    },
    AUTUMN ("秋天","秋高气爽") {
        @Override
        public void show() {
            System.out.println("这是一个"秋天","秋高气爽"");
        }
    },
    WINTER ("冬天","寒风刺骨") {
        @Override
        public void show() {
            System.out.println("这是一个"冬天","寒风刺骨"");
        }
    };

    //1.声明Season对象的属性:用private final来修饰：
    private final String seasonName;
    private final String seasonDesc;
    //2.私有化构造器（外界不能再多造了）
    private Season1(String seasonName,String seasonDesc){
        this.seasonName = seasonName;
        this.seasonDesc = seasonDesc;
    }
    //4.其他诉求1：获取枚举类的属性

    public String getSeasonName() {
        return seasonName;
    }

    public String getSeasonDesc() {
        return seasonDesc;
    }
    //4.其他诉求2：提供toString()方法：
    @Override
    public String toString() {
        return "Season1{" +
                "seasonName='" + seasonName + ''' +
                ", seasonDesc='" + seasonDesc + ''' +
                '}';
    }


//    @Override
//    public void show() {
//        System.out.println("这是一个季节");
//    }

}

package com.atguigu.java1;

import com.sun.org.apache.xpath.internal.SourceTree;

import java.lang.annotation.Repeatable;


public class AnnotationTest {
    public static void main(String[] args) {

        @SuppressWarnings("unused")
        int i = 0;
    }
}



//JDK8之前的写法：
//@MyAnnotations({@MyAnnotation(value = "hi"),@MyAnnotation(value = "hello")})

@MyAnnotation(value = "hi")
@MyAnnotation(value = "hello")
class Person{
    private String name;
    private int age;

    public Person() {
    }

    public Person(String name, int age) {
        this.name = name;
        this.age = age;
    }

    public void walk(){
        System.out.println("人走路");
    }

    public void eat(){
        System.out.println("人吃饭");
    }
}
interface Info{

    public abstract void show();
}

class Student extends Person implements Info{
    public Student(String name, int age){
        super(name,age);
    }

    @Override
    public void walk() {
        System.out.println("学生走路");
    }

    @Override
    public void show() {

    }
}

package com.atguigu.java1;
import java.lang.annotation.Repeatable;

@Repeatable(MyAnnotations.class)

public @interface MyAnnotation {
    String value() default "hello";
}

package com.atguigu.java1;


public @interface MyAnnotations {
    MyAnnotation[] value();
}