java8获取list对象中某个字段最大值的对象

    @Test
    public void test() {
        List<Sensor> sensorMongoList = Lists.newArrayList();
        Sensor sensor = new Sensor();
        sensor.setId("123123");
        sensor.setNum("1");
        sensorMongoList.add(sensor);

        Sensor sensorTwo = new Sensor();
        sensorTwo.setId("3423423");
        sensorTwo.setNum("2");
        sensorMongoList.add(sensorTwo);

        Sensor sensor1 = sensorMongoList.stream().max(Comparator.comparing(Sensor::getNum)).get();
        String num = sensor1.getNum();
        num = String.valueOf(Integer.parseInt(num) + 1);
        System.err.println(num);

    }