JAVA中的函数式接口Function和BiFunction详解

public class function {
    static Function<String, Integer> strLen = new Function<String, Integer>() {
        @Override
        public Integer apply(String s) {
            int length = s.length();
            return length;
        }
    };
    public static void main(String[] args) {
        System.out.println("Function 示例, 字符串长度: " + strLen.apply("Hello"));
    }
}

public class function {
    static Function<String, Integer> strLen = s -> {
        int length = s.length();
        return length;
    };
    public static void main(String[] args) {
        System.out.println("Function 示例, 字符串长度: " + strLen.apply("Hello"));
    }
}

public class function {
    static Function<String, Integer> strLen = String::length;
    public static void main(String[] args) {
        System.out.println("Function 示例, 字符串长度: " + strLen.apply("Hello"));
    }
}

private Function<Filters , LinkedHashMap<String, Long>>  RESULT_CONVENT = new Function<Filters, LinkedHashMap<String, Long>>() {
        @Override
        public LinkedHashMap<String, Long> apply(Filters term) {
            LinkedHashMap<String, Long> result = new LinkedHashMap<>();
            for (Filters.Bucket temp : term.getBuckets()) {
                MultiBucketsAggregation statisticTimeTerm = temp.getAggregations().get("Time");
                for (MultiBucketsAggregation.Bucket timeTemp : statisticTimeTerm.getBuckets()) {
                    result.put(timeTemp.getKeyAsString(), timeTemp.getDocCount());
                }
            }
            return result;
        }
    };

    private Function<Filters , LinkedHashMap<String, Long>>  RESULT_CONVENT = term -> {
        LinkedHashMap<String, Long> result = new LinkedHashMap<>();
        for (Filters.Bucket temp : term.getBuckets()) {
            MultiBucketsAggregation statisticTimeTerm = temp.getAggregations().get("Time");
            for (MultiBucketsAggregation.Bucket timeTemp : statisticTimeTerm.getBuckets()) {
                result.put(timeTemp.getKeyAsString(), timeTemp.getDocCount());
            }
        }
        return result;
    };

public class function {
    static BiFunction<String, Integer, Boolean> expectLength = (s, num) -> s.length() == num;
    public static void main(String[] args) {
        System.out.print("BiFunction 示例, 字符串长度是否符合预期? " + expectLength.apply("21yi", 4));
    }
}