1.需求

在大数据的实时处理中,实时的大屏展示已经成了一个很重要的展示项,比如最有名的双十一大屏实时销售总价展示。除了这个,还有一些其他场景的应用,比如我们在我们的后台系统实时的展示我们网站当前的pv、uv等等,其实做法都是类似的。

需求如下:

  1. 实时计算出当天零点截止到当前时间的销售总额
  2. 计算出各个分类的销售top3
  3. 每秒钟更新一次统计结果

2.数据

首先我们通过自定义source 模拟订单的生成,生成了一个Tuple2,第一个元素是分类,第二个元素表示这个分类下产生的订单金额,金额我们通过随机生成.

/**
 * 自定义数据源实时产生订单数据Tuple2<分类, 金额>
 */
public static class MySource implements SourceFunction<Tuple2<String, Double>>{
    private boolean flag = true;
    private String[] categorys = {"女装", "男装","图书", "家电","洗护", "美妆","运动", "游戏","户外", "家具","乐器", "办公"};
    private Random random = new Random();

    @Override
    public void run(SourceContext<Tuple2<String, Double>> ctx) throws Exception {
        while (flag){
            //随机生成分类和金额
            int index = random.nextInt(categorys.length);//[0~length) ==> [0~length-1]
            String category = categorys[index];//获取的随机分类
            double price = random.nextDouble() * 100;//注意nextDouble生成的是[0~1)之间的随机数,*100之后表示[0~100)
            ctx.collect(Tuple2.of(category,price));
            Thread.sleep(20);
        }
    }

    @Override
    public void cancel() {
        flag = false;
    }
}

3.实现步骤

    1. env
    2. source
    3. transformation
    • 3.1定义大小为一天的窗口,第二个参数表示中国使用的UTC+08:00时区比UTC时间早
    .keyBy(0)
    window(TumblingProcessingTimeWindows.of(Time.days(1), Time.hours(-8))• 3.2定义一个1s的触发器
    .trigger(ContinuousProcessingTimeTrigger.of(Time.seconds(1)))• 3.3聚合结果.aggregate(new PriceAggregate(), new WindowResult());
    • 3.4看一下聚合的结果
    CategoryPojo(category=男装, totalPrice=17225.26, dateTime=2020-10-20 08:04:12)4. 使用上面聚合的结果,实现业务需求:
    result.keyBy(“dateTime”)
    //每秒钟更新一次统计结果 .window(TumblingProcessingTimeWindows.of(Time.seconds(1)))
     //在ProcessWindowFunction中实现该复杂业务逻辑
     .process(new WindowResultProcess());
    • 4.1. 实时计算出当天零点截止到当前时间的销售总额
    • 4.2.计算出各个分类的销售top3
    • 4.3.每秒钟更新一次统计结果
    1. execute

    4.代码示例

    package cn.wangting.action;
    
    import lombok.AllArgsConstructor;
    import lombok.Data;
    import lombok.NoArgsConstructor;
    import org.apache.commons.lang3.StringUtils;
    import org.apache.commons.lang3.time.FastDateFormat;
    import org.apache.flink.api.common.RuntimeExecutionMode;
    import org.apache.flink.api.common.functions.AggregateFunction;
    import org.apache.flink.api.java.tuple.Tuple2;
    import org.apache.flink.streaming.api.datastream.DataStream;
    import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
    import org.apache.flink.streaming.api.functions.source.SourceFunction;
    import org.apache.flink.streaming.api.functions.windowing.ProcessWindowFunction;
    import org.apache.flink.streaming.api.functions.windowing.WindowFunction;
    import org.apache.flink.streaming.api.windowing.assigners.TumblingProcessingTimeWindows;
    import org.apache.flink.streaming.api.windowing.time.Time;
    import org.apache.flink.streaming.api.windowing.triggers.ContinuousProcessingTimeTrigger;
    import org.apache.flink.streaming.api.windowing.windows.TimeWindow;
    import org.apache.flink.util.Collector;
    import java.math.BigDecimal;
    import java.math.RoundingMode;
    import java.util.List;
    import java.util.PriorityQueue;
    import java.util.Queue;
    import java.util.Random;
    import java.util.stream.Collectors;
    
    
    public class DoubleElevenBigScreem {
        public static void main(String[] args) throws Exception {
            //TODO 1.env
            StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
            env.setRuntimeMode(RuntimeExecutionMode.AUTOMATIC);
            env.setParallelism(1);
            //TODO 2.source
            DataStream<Tuple2<String, Double>> orderDS = env.addSource(new MySource());
    
            //TODO 3.transformation
            DataStream<CategoryPojo> tempAggResult = orderDS
                    .keyBy(t -> t.f0)
                    .window(TumblingProcessingTimeWindows.of(Time.days(1), Time.hours(-8)))
                    .trigger(ContinuousProcessingTimeTrigger.of(Time.seconds(1)))
                    .aggregate(new PriceAggregate(), new WindowResult());
            tempAggResult.print("初步聚合的各个分类的销售总额");
            //TODO 4.sink
            tempAggResult.keyBy(CategoryPojo::getDateTime)
                    .window(TumblingProcessingTimeWindows.of(Time.seconds(1)))
                    .process(new FinalResultWindowProcess());
    
            //TODO 5.execute
            env.execute();
        }
    
        // 自定义数据源实时产生订单数据Tuple2<分类, 金额>
        public static class MySource implements SourceFunction<Tuple2<String, Double>> {
            private boolean flag = true;
            private String[] categorys = {"女装", "男装", "图书", "家电", "洗护", "美妆", "运动", "游戏", "户外", "家具", "乐器", "办公"};
            private Random random = new Random();
            @Override
            public void run(SourceContext<Tuple2<String, Double>> ctx) throws Exception {
                while (flag) {
                    int index = random.nextInt(categorys.length);
                    String category = categorys[index];
                    double price = random.nextDouble() * 100;
                    ctx.collect(Tuple2.of(category, price));
                    Thread.sleep(20);
                }
            }
            @Override
            public void cancel() {
                flag = false;
            }
        }
    
        // 自定义聚合函数,指定聚合规则
        private static class PriceAggregate implements AggregateFunction<Tuple2<String, Double>, Double, Double> {
            @Override
            public Double createAccumulator() {
                return 0D;
            }
    
            @Override
            public Double add(Tuple2<String, Double> value, Double accumulator) {
                return value.f1 + accumulator;
            }
    
            @Override
            public Double getResult(Double accumulator) {
                return accumulator;
            }
    
            @Override
            public Double merge(Double a, Double b) {
                return a + b;
            }
        }
    
        // 自定义窗口函数,指定窗口数据收集规则
        private static class WindowResult implements WindowFunction<Double, CategoryPojo, String, TimeWindow> {
            private FastDateFormat df = FastDateFormat.getInstance("yyyy-MM-dd HH:mm:ss");
            @Override
            public void apply(String category, TimeWindow window, Iterable<Double> input, Collector<CategoryPojo> out) throws Exception {
                long currentTimeMillis = System.currentTimeMillis();
                String dateTime = df.format(currentTimeMillis);
                Double totalPrice = input.iterator().next();
                out.collect(new CategoryPojo(category,totalPrice,dateTime));
            }
        }
    
        // 用于存储聚合的结果
        @Data
        @AllArgsConstructor
        @NoArgsConstructor
        public static class CategoryPojo {
            private String category;
            private double totalPrice;
            private String dateTime;
        }
    
        // 自定义窗口完成销售总额统计和分类销售额top3统计并输出
        private static class FinalResultWindowProcess extends ProcessWindowFunction<CategoryPojo, Object, String, TimeWindow> {
            @Override
            public void process(String dateTime, Context context, Iterable<CategoryPojo> elements, Collector<Object> out) throws Exception {
                double total = 0D;
                Queue<CategoryPojo> queue = new PriorityQueue<>(3,
                        (c1, c2) -> c1.getTotalPrice() >= c2.getTotalPrice() ? 1 : -1);
                for (CategoryPojo element : elements) {
                    double price = element.getTotalPrice();
                    total += price;
                    if(queue.size()< 3){
                        queue.add(element);
                    }else{
                        if(price >= queue.peek().getTotalPrice()){
                            queue.poll();
                            queue.add(element);
                        }
                    }
                }
                List<String> top3List = queue.stream()
                        .sorted((c1, c2) -> c1.getTotalPrice() >= c2.getTotalPrice() ? -1 : 1)
                        .map(c -> "分类:" + c.getCategory() + " 金额:" + c.getTotalPrice())
                        .collect(Collectors.toList());
                double roundResult = new BigDecimal(total).setScale(2, RoundingMode.HALF_UP).doubleValue();
                System.out.println("时间: "+dateTime +" 总金额 :" + roundResult);
                System.out.println("top3: \n" + StringUtils.join(top3List,"\n"));
            }
        }
    }

    5.运行效果

    时间: 2022-09-29 15:01:50 总金额 :7342.27
    top3: 
    分类:家具 金额:1104.831122065498
    分类:运动 金额:915.3967483816951
    分类:家电 金额:841.1627522295081
    初步聚合的各个分类的销售总额> DoubleElevenBigScreem.CategoryPojo(category=家电, totalPrice=915.5064000160678, dateTime=2022-09-29 15:01:51)
    初步聚合的各个分类的销售总额> DoubleElevenBigScreem.CategoryPojo(category=办公, totalPrice=1041.8726323584178, dateTime=2022-09-29 15:01:51)
    初步聚合的各个分类的销售总额> DoubleElevenBigScreem.CategoryPojo(category=美妆, totalPrice=503.02560448369053, dateTime=2022-09-29 15:01:51)
    初步聚合的各个分类的销售总额> DoubleElevenBigScreem.CategoryPojo(category=运动, totalPrice=1019.2793212446227, dateTime=2022-09-29 15:01:51)
    初步聚合的各个分类的销售总额> DoubleElevenBigScreem.CategoryPojo(category=游戏, totalPrice=556.7830812774787, dateTime=2022-09-29 15:01:51)
    初步聚合的各个分类的销售总额> DoubleElevenBigScreem.CategoryPojo(category=户外, totalPrice=696.3542078051894, dateTime=2022-09-29 15:01:51)
    初步聚合的各个分类的销售总额> DoubleElevenBigScreem.CategoryPojo(category=乐器, totalPrice=483.0946634839456, dateTime=2022-09-29 15:01:51)
    初步聚合的各个分类的销售总额> DoubleElevenBigScreem.CategoryPojo(category=洗护, totalPrice=725.1418698615925, dateTime=2022-09-29 15:01:51)
    初步聚合的各个分类的销售总额> DoubleElevenBigScreem.CategoryPojo(category=男装, totalPrice=615.631037605471, dateTime=2022-09-29 15:01:51)
    初步聚合的各个分类的销售总额> DoubleElevenBigScreem.CategoryPojo(category=女装, totalPrice=660.7646487962378, dateTime=2022-09-29 15:01:51)
    初步聚合的各个分类的销售总额> DoubleElevenBigScreem.CategoryPojo(category=家具, totalPrice=1383.8312618867728, dateTime=2022-09-29 15:01:51)
    初步聚合的各个分类的销售总额> DoubleElevenBigScreem.CategoryPojo(category=女装, totalPrice=906.2431893294321, dateTime=2022-09-29 15:01:52)
    时间: 2022-09-29 15:01:51 总金额 :9095.84
    top3: 
    分类:家具 金额:1383.8312618867728
    分类:办公 金额:1041.8726323584178
    分类:运动 金额:1019.2793212446227
    初步聚合的各个分类的销售总额> DoubleElevenBigScreem.CategoryPojo(category=家具, totalPrice=1462.202891610573, dateTime=2022-09-29 15:01:52)
    初步聚合的各个分类的销售总额> DoubleElevenBigScreem.CategoryPojo(category=运动, totalPrice=1109.9560846950264, dateTime=2022-09-29 15:01:52)
    初步聚合的各个分类的销售总额> DoubleElevenBigScreem.CategoryPojo(category=美妆, totalPrice=515.9936934014466, dateTime=2022-09-29 15:01:52)
    初步聚合的各个分类的销售总额> DoubleElevenBigScreem.CategoryPojo(category=家电, totalPrice=999.9819796981208, dateTime=2022-09-29 15:01:52)
    初步聚合的各个分类的销售总额> DoubleElevenBigScreem.CategoryPojo(category=图书, totalPrice=708.0261692936298, dateTime=2022-09-29 15:01:52)
    初步聚合的各个分类的销售总额> DoubleElevenBigScreem.CategoryPojo(category=办公, totalPrice=1178.0235983868834, dateTime=2022-09-29 15:01:52)
    初步聚合的各个分类的销售总额> DoubleElevenBigScreem.CategoryPojo(category=男装, totalPrice=839.431520006262, dateTime=2022-09-29 15:01:52)
    初步聚合的各个分类的销售总额> DoubleElevenBigScreem.CategoryPojo(category=户外, totalPrice=841.6338202091758, dateTime=2022-09-29 15:01:52)
    初步聚合的各个分类的销售总额> DoubleElevenBigScreem.CategoryPojo(category=游戏, totalPrice=556.7830812774787, dateTime=2022-09-29 15:01:52)
    初步聚合的各个分类的销售总额> DoubleElevenBigScreem.CategoryPojo(category=洗护, totalPrice=725.1418698615925, dateTime=2022-09-29 15:01:52)
    初步聚合的各个分类的销售总额> DoubleElevenBigScreem.CategoryPojo(category=乐器, totalPrice=834.0851355693773, dateTime=2022-09-29 15:01:52)

    案例2.Flink实现订单自动好评

    1.需求

    在电商领域会有这么一个场景,如果用户买了商品,在订单完成之后,一定时间之内没有做出评价,系统自动给与五星好评,用Flink的定时器来简单实现这一功能

    2.数据

    自定义source模拟生成一些订单数据,二元组Tuple3,包含用户id,订单id和订单完成时间三个字段.

    /**
     * 自定义source实时产生订单数据Tuple3<用户id,订单id, 订单生成时间>
     */
    public static class MySource implements SourceFunction<Tuple3<String, String, Long>> {
        private boolean flag = true;
        @Override
        public void run(SourceContext<Tuple3<String, String, Long>> ctx) throws Exception {
            Random random = new Random();
            while (flag) {
                String userId = random.nextInt(5) + "";
                String orderId = UUID.randomUUID().toString();
                long currentTimeMillis = System.currentTimeMillis();
                ctx.collect(Tuple3.of(userId, orderId, currentTimeMillis));
                Thread.sleep(500);
            }
        }
        @Override
        public void cancel() {
            flag = false;
        }
    }

    3.实现步骤

    1. env
    2. source
    3. transformation
    设置经过interval毫秒用户未对订单做出评价,自动给与好评.为了演示方便,设置5s的时间
    long interval = 5000L;
    分组后使用自定义KeyedProcessFunction完成定时判断超时订单并自动好评
    dataStream.keyBy(0).process(new TimerProcessFuntion(interval));• 3.1定义MapState类型的状态,key是订单号,value是订单完成时间
    • 3.2创建MapState
    MapStateDescriptor<String, Long> mapStateDesc =
     new MapStateDescriptor<>(“mapStateDesc”, String.class, Long.class);
     mapState = getRuntimeContext().getMapState(mapStateDesc);• 3.3注册定时器
    mapState.put(value.f0, value.f1);
    ctx.timerService().registerProcessingTimeTimer(value.f1 + interval);
    3.4定时器被触发时执行并输出结果4. sink
    5. execute

    4.代码示例

    package cn.wangting.action;
    
    import org.apache.flink.api.common.RuntimeExecutionMode;
    import org.apache.flink.api.common.state.MapState;
    import org.apache.flink.api.common.state.MapStateDescriptor;
    import org.apache.flink.api.java.tuple.Tuple3;
    import org.apache.flink.configuration.Configuration;
    import org.apache.flink.streaming.api.datastream.DataStream;
    import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
    import org.apache.flink.streaming.api.functions.KeyedProcessFunction;
    import org.apache.flink.streaming.api.functions.source.SourceFunction;
    import org.apache.flink.util.Collector;
    import java.util.Iterator;
    import java.util.Map;
    import java.util.Random;
    import java.util.UUID;
    
    public class OrderAutomaticFavorableComments {
        public static void main(String[] args) throws Exception {
            //TODO 1.env
            StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
            env.setRuntimeMode(RuntimeExecutionMode.AUTOMATIC);
            env.setParallelism(1);
    
            //TODO 2.source
            DataStream<Tuple3<String, String, Long>> orderDS = env.addSource(new MySource());
    
            //TODO 3.transformation
            long interval = 5000L;//5s
            orderDS.keyBy(t -> t.f0)
                    .process(new TimerProcessFunction(interval));
    
            //TODO 4.sink
    
            //TODO 5.execute
            env.execute();
        }
    
        // 自定义source实时产生订单数据Tuple3<用户id,订单id, 订单生成时间>
        public static class MySource implements SourceFunction<Tuple3<String, String, Long>> {
            private boolean flag = true;
    
            @Override
            public void run(SourceContext<Tuple3<String, String, Long>> ctx) throws Exception {
                Random random = new Random();
                while (flag) {
                    String userId = random.nextInt(5) + "";
                    String orderId = UUID.randomUUID().toString();
                    long currentTimeMillis = System.currentTimeMillis();
                    ctx.collect(Tuple3.of(userId, orderId, currentTimeMillis));
                    Thread.sleep(500);
                }
            }
    
            @Override
            public void cancel() {
                flag = false;
            }
        }
    
        /**
         * 自定义ProcessFunction完成订单自动好评
         * 进来一条数据应该在interval时间后进行判断该订单是否超时是否需要自动好评
         * abstract class KeyedProcessFunction<K, I, O>
         */
        private static class TimerProcessFunction extends KeyedProcessFunction<String, Tuple3<String, String, Long>, Object> {
            private long interval;//订单超时时间 传进来的是5000ms/5s
            public TimerProcessFunction(long interval) {
                this.interval = interval;
            }
    
            private MapState<String, Long> mapState = null;
    
            @Override
            public void open(Configuration parameters) throws Exception {
                MapStateDescriptor<String, Long> mapStateDescriptor = new MapStateDescriptor<>("mapState", String.class, Long.class);
                mapState = getRuntimeContext().getMapState(mapStateDescriptor);
            }
    
            @Override
            public void processElement(Tuple3<String, String, Long> value, Context ctx, Collector<Object> out) throws Exception {
                mapState.put(value.f1, value.f2);
                ctx.timerService().registerProcessingTimeTimer(value.f2 + interval);
            }
    
            @Override
            public void onTimer(long timestamp, OnTimerContext ctx, Collector<Object> out) throws Exception {
                Iterator<Map.Entry<String, Long>> iterator = mapState.iterator();
                while (iterator.hasNext()) {
                    Map.Entry<String, Long> map = iterator.next();
                    String orderId = map.getKey();
                    Long orderTime = map.getValue();
                    if (!isFavorable(orderId)) {
                        if (System.currentTimeMillis() - orderTime >= interval) {
                            System.out.println("orderId:" + orderId + "该订单已经超时未评价,系统自动给与好评!....");
                            iterator.remove();
                            mapState.remove(orderId);
                        }
                    } else {
                        System.out.println("orderId:" + orderId + "该订单已经评价....");
                        iterator.remove();
                        mapState.remove(orderId);
                    }
                }
            }
    
            public boolean isFavorable(String orderId) {
                return orderId.hashCode() % 2 == 0;
            }
        }
    }

    5.运行效果

    orderId:ece38a3b-444d-4f38-b491-35c0d77ad472该订单已经评价....
    orderId:87ea561a-73ef-425b-8e1f-7a0387d0c7c9该订单已经评价....
    orderId:4aafcce9-1fc6-4b52-863f-e5c7dacc5344该订单已经超时未评价,系统自动给与好评!....
    orderId:98a19e40-dabf-43cc-a3ee-0c76d5402e86该订单已经超时未评价,系统自动给与好评!....
    orderId:4f3f520a-160c-400d-8f58-fcb4b3e2ae8d该订单已经超时未评价,系统自动给与好评!....
    orderId:d852a77f-7800-41af-801d-950baed8f65f该订单已经超时未评价,系统自动给与好评!....
    orderId:7663584c-c90c-42d9-a0fb-53fcca7ffe43该订单已经超时未评价,系统自动给与好评!....
    orderId:681c8d6c-079a-4ccd-8470-d5cb3c464fd1该订单已经评价....
    orderId:31418829-eb7e-40d5-87ce-1702f64ffe3a该订单已经评价....
    orderId:2ee6472c-1705-4372-b5b0-6f84b9763e25该订单已经超时未评价,系统自动给与好评!....
    orderId:dfe6136b-ad6b-416f-ab04-47b0d42d3dbc该订单已经超时未评价,系统自动给与好评!....
    orderId:638992d2-8983-4bef-928f-b8051d9f45b6该订单已经超时未评价,系统自动给与好评!....
    orderId:cb57f913-152f-4535-b8fd-9d0498c46b1a该订单已经评价....
    orderId:6efea3a6-4785-4e51-8fd6-e39057d9d1f9该订单已经评价....