public class SeasonTest {
    public static void main(String[] args) {
        Season spring = Season.SPRING;
        System.out.println(spring);
    }
}
class Season{
    //1.声明对象属性为private final
    private final String seasonName; //季节名字
    private final String seasonDec;  //季节描述
    //2.构造器应该是private的
    private Season(String seasonName,String seasonDec){
        this.seasonName = seasonName;
        this.seasonDec = seasonDec;  //{seasonName='春天', seasonDec='春暖花开'}
    }
    //3.创建确定个数的实例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","冰天雪地");

    //4.根据需求，可以选择性地创建其他函数
    public String getSeasonName() { return seasonName;}

    public String getSeasonDec() { return seasonDec;}
    
    @Override
    public String toString() {
        return "{" +
                "seasonName='" + seasonName + '\'' +
                ", seasonDec='" + seasonDec + '\'' +
                '}';
    }
}

enum Season{
    //1.提供当前枚举类的对象，多个对象之间用","隔开，末尾对象";"结束
    SPRING("春天","春暖花开"),
    SUMMER("夏天","夏日炎炎"),
    AUTUMN("秋天","秋高气爽"),
    WINTER("冬天","冰天雪地");
    //2.声明Season对象的属性:private final修饰
    private final String seasonName;
    private final String seasonDesc;

    //3.构造器应该是private的，enum里面可以省略private关键字
    Season(String seasonName,String seasonDesc){
        this.seasonName = seasonName;
        this.seasonDesc = seasonDesc;
    }
    
    //可以根据需要声明其他方法
    public String getSeasonName() {
        return seasonName;
    }

    public String getSeasonDesc() {
        return seasonDesc;
    }
}

public class SeasonTest2 {
    public static void main(String[] args) {
        //toString方法：
        System.out.println(Season2=.SPRING); //SPRING
        //父类是Enum类
        System.out.println(Season2.class.getSuperclass()); //class java.lang.Enum

        //values方法
        Season[] values = Season.values();
        for(Season i: values){
            System.out.println(i);
        }
        /*输出：
        SPRING
        SUMMER
        AUTUMN
        WINTER
        */

        //valueOf(String str)方法,返回枚举类中，对象名是str的枚举类对象
        Season winter = Season.valueOf("WINTER");
        System.out.println(winter.toString()); //WINTER
        //等同于Systou.out.println(winter)

        //枚举类在switch中的应用
        Season season = Season.SPRING;
        switch (season){
            case SPRING:
                System.out.println("春天"); //输出：春天
                break;
            case SUMMER:
                System.out.println("夏天");
                break;
            case AUTUMN:
                System.out.println("秋天");
                break;
            case WINTER:
                System.out.println("冬天");
                break;
        }
    }
}

public class SeasonTest2 {
    public static void main(String[] args) {
        //values方法
        Season2[] values = Season2.values();
        for(Season2 i: values){
            System.out.println(i);
            i.info();
        }
    }
}

enum Season2 implements Info{
    //每个枚举变量单独实现Info接口中的方法
    SPRING ("春天","春暖花开"){
        public void info(){
            System.out.println("spring");
        }
    },
    SUMMER ("夏天","夏日炎炎"){
        public void info(){
            System.out.println("summer");
        }
    },
    AUTUMN ("秋天","秋高气爽"){
        public void info(){
            System.out.println("autumn");
        }
    },
    WINTER("冬天","冰天雪地"){
        public void info(){
            System.out.println("winter");
        }
    };

    private final String seasonName;
    private final String seasonDec;
    Season2(String seasonName,String seasonDec){
        this.seasonName = seasonName;
        this.seasonDec = seasonDec;
    }

}
interface Info{
    void info();
}
/*
输出结果为：
SPRING
spring
SUMMER
summer
AUTUMN
autumn
WINTER
winter
*/

/**
*@author xxx
*@version 1.0
*@see Math.java
*/

public class Hello {
    //使用是指定配置参数
    @Report(type = 3,level = "level",value = "string")
    public int n;
    
    //指定部分参数
    @Report(level = "level",value = "string")
    public int p;

    @Report(value = "string") // 只对value赋值，等同于@Report("string")
    public int x;

    @Report  //对所有参数使用默认值
    public int y;
}
//以下是自定义的一个注解，如果是public修饰的，必须单独放在一个java文件中
//三个配置参数都有默认值，因此使用的时候可以指定，也可以不指定
public @interface Report {
    int type() default 0;  //类型为int，配置参数名为type，默认值是0
    String level() default "info";
    String value() default "";
}

@Retention(RetentionPolicy.RUNTIME)
public @interface MyAnnotation {
    int type() default 0;
    String level() default "info";
    String value() default "";
}

//注意：这三个类都是public的，需要分别写在三个文件中
@Inherited
@Retention(RetentionPolicy.RUNTIME) 
@Target({TYPE, FIELD, METHOD, PARAMETER, CONSTRUCTOR, LOCAL_VARIABLE})
public @interface MyAnnotations {
    MyAnnotation[] value();
}

@Inherited
@Repeatable(MyAnnotations.class) //Repeatable的参数是容器注解的类型
@Retention(RetentionPolicy.RUNTIME)
@Target({TYPE, FIELD, METHOD, PARAMETER, CONSTRUCTOR, LOCAL_VARIABLE,
         TYPE_PARAMETER,TYPE_USE})
public @interface MyAnnotation {
    String value() default "hello";
}

//此时MyAnnotation注解可以重复使用
@MyAnnotation(value="hi")  
@MyAnnotation(value="abc")
public class Person{}

class Test<@MyAnnotation T>{ //写在声明语句中
    public void show() throws @MyAnnotation RuntimeException{
        ArrayList<@MyAnnotation String> list = new ArrayList<>();
        int num = (@MyAnnotation int) 10L; //写在任何语句中
    }
}