java函数式编程Consumer,Supplier,Function

代码示例

@Slf4j
public class DemoJavaFunction {
    public static void main(String[] args) {
        // 第一步：模拟入参数据的准备
        Supplier<DemoJavaFunction.DemoInput> supplier = ()->{
            DemoJavaFunction.DemoInput input = new DemoJavaFunction.DemoInput();
            input.setId(100);
            input.setInputMsg("inputMsg_value");
            input.setMsg("消息");
            input.setFlag(true);
            return input;
        };

        //第二步：Function作用：函数编程入参和业务中间数据流的转换
        Function<DemoJavaFunction.DemoInput, DemoJavaFunction.DemoDto> function = input -> {
            DemoJavaFunction.DemoDto demoDto = new DemoJavaFunction.DemoDto();
            demoDto.setMsg(input.getMsg()+":Function");
            demoDto.setId(input.getId());
            demoDto.setInputMsg("数据正在处理");
            demoDto.setInterState("中间状态");
            return demoDto;
        };

        //第三步：出参数据业务操作
        DemoJavaFunction.DemoOutput output = new DemoJavaFunction.DemoOutput();
        Consumer<DemoJavaFunction.DemoDto> consumer = input -> {
            log.info("Consumer flag is true input:{}", input);
            output.setId(input.getId());
            output.setMsg(input.getMsg());
            output.setInterState(input.getInterState());
            output.setFlag(input.getFlag());
            output.setOutputFlag("OutputFlag出参数");

        };
        //第四步：业务逻辑调用
        BiConsumer<Consumer<DemoJavaFunction.DemoDto>, DemoJavaFunction.DemoDto> biConsumer = (callback, value) -> {
            for(int i = 0; i < 10; i++){
                //回调第三步操作
                callback.accept(value);
            }
        };

        //第五步：注意生产者到双向消费者执行过程
        biConsumer.accept(consumer, function.apply(supplier.get()));
        log.info("output:{}", output);
        //断言操作
        Predicate<String> predicate = (x)-> "A".equals(x);
        System.out.println(predicate.test("B"));
    }



    @Data
    @NoArgsConstructor
    @AllArgsConstructor
    static class DemoEntity{
        private Integer id;
        private String msg;
        private Boolean flag;
    }

    @Data
    @NoArgsConstructor
    @AllArgsConstructor
    static class DemoInput{
        private Integer id;
        private String msg;
        private Boolean flag;
        private String inputMsg;
    }

    @Data
    @NoArgsConstructor
    @AllArgsConstructor
    static class DemoDto{
        private Integer id;
        private String msg;
        private Boolean flag;
        private String inputMsg;
        private String interState;
    }

    @Data
    @NoArgsConstructor
    @AllArgsConstructor
    static class DemoOutput{
        private Integer id;
        private String msg;
        private Boolean flag;
        private String interState;
        private String outputFlag;
    }
}