Java8四大核心接口示例

public static void main(String[] args) {
        TestLambda testLambda = new TestLambda();
        //消费型，消费 一个参数，无返回值
        testLambda.consumer(1000,(money)->{
            System.out.printf("消费%f元",money);
        });
        //供给型，产生随机数 无参数，有返回值
        System.out.println(testLambda.getNumList(5,()->{
            return Math.random()*100;
        }));
        //函数型，剔除空格 一个参数，又返回值
        System.out.println(testLambda.strHandler("\t\t\thello wolrd", (s) -> {
            return s.trim();
        }));
        //断言型，处理字符串 有参数，有返回值(boolean类型)
        Predicate predicate = (str)->{
            String s = (String) str;
            if (s.contains("china")){
               return true;
            }
            return false;
        };
        List list = new ArrayList();
        list.add("i love china");list.add("i love chin1a");
        list.add("are you speaking chinese ");list.add("china chaina");
        System.out.println(testLambda.filterStr(list,predicate));

    }
    public void consumer(double money,Consumer<Double> consumer){
        consumer.accept(money);
    }
    public List<Double> getNumList(int num,Supplier<Double> supplier){
        List<Double> list = new ArrayList<>();
        for (int i = 0; i < num; i++) {
            Double n = supplier.get();
            list.add(n);
        }
        return list;
    }
    public String strHandler(String str,Function<String ,String > function){
        return function.apply(str);
    }
    public List<String > filterStr(List<String > list, Predicate<String> predicate){
        List list1 = new ArrayList();
        for (String string : list) {
            if (predicate.test(string)){
                list1.add(string);
            }
        }
        return list1;
    }