springboot webflux flux 使用示例（聚合操作）

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springboot webflux flux 使用示例（聚合操作）

 

 

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group

 

public class Test {

    public static void main(String[] args){
        Flux.just(1,2,3,4,5,6).groupBy(value -> value<3)
                .subscribe(flux -> {
                    if (Objects.equals(flux.key(),Boolean.TRUE)){
                        System.out.print("key爲"+flux.key()+"的個數爲：");
                        flux.count().subscribe(System.out::println);
                    }
                });
    }
}

 

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控制檯輸出

 

key爲true的個數爲：2

 

 

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sort、distinct、count

 

public class Test2 {

    public static void main(String[] args){
        Flux.just(1,20,31,4,5,6,65,23,12,32).sort()
                .subscribe(value ->System.out.print(value+"  "));

        System.out.println("\n\n***************");
        Flux.just("瓜田李下","瓜田李下2","hello world","hello world","gtlx","瓜田李下")
                .distinct()
                .subscribe(value -> System.out.print(value+"  "));

        System.out.println("\n\n***************");
        Flux.just("瓜田李下","瓜田李下2","hello world","hello world2")
                .count()
                .subscribe(value -> System.out.println("元素的個數爲："+value));
    }
}

 

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1  4  5  6  12  20  23  31  32  65  

***************
瓜田李下  瓜田李下2  hello world  gtlx  

***************
元素的個數爲：4

 

 

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reduce

 

public class Test3 {

    public static void main(String[] args){
        Flux.just(1,2,3,4).reduce(Integer::sum).subscribe(System.out::println);
        Flux.just(1,2,3,4).reduce(10,Integer::sum).subscribe(System.out::println);
    }
}

 

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控制檯輸出

 

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