优化按方向计算的任务的注释，修改错误，便于理解

realtime/hologram-streaming/src/main/java/com/zhht/irn/job/DirectionEvalJob.java

@@ -10,14 +10,10 @@ import com.zhht.irn.utils.DorisUtils;
 import com.zhht.irn.utils.FlinkUtils;
 import com.zhht.irn.utils.StringUtils;
 import org.apache.doris.flink.sink.DorisSink;
-import org.apache.flink.api.common.eventtime.WatermarkStrategy;
 import org.apache.flink.api.common.functions.MapFunction;
 import org.apache.flink.streaming.api.datastream.DataStream;
-import org.apache.flink.streaming.api.datastream.KeyedStream;
 import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
 
-import java.time.Duration;
-
 import static com.zhht.irn.utils.DateUtils.longToStandardFormatString;
 
 /**
@@ -44,18 +40,13 @@ public class DirectionEvalJob {
                 FlinkUtils.createKafkaStream(args, env, Constant.TRAVEL_EVENT_TOPIC_NAME, "DirectionEvalJob")
                         .map(record -> JSON.parseObject(record, TravelEvent.class)).filter(event -> StringUtils.isNotEmpty(event.getEventLineId()));
 
-
-        // 周期数据 interval join 事件流数据，计算 交通流量和排队长度两个指标
-        // 旅行事件数据流
-        KeyedStream<TravelEvent, String> travelEventKeyedStream = travelEventStream
-                .keyBy(record -> record.getCrossId());
-
         // 定义好doris sink builder
         DorisSink.Builder<String> builder = DorisUtils.getBuilder("doris.properties", args, "app_direction_eval_second_metric");
 
-        // 周期数据join 旅行事件
+        // 周期数据 connect 事件流数据，计算 交通流量和排队长度两个指标
+        // (无法join，因为计算是根据周期动态触发的，无法确定join条件)
         cycleStream.keyBy(record -> record.getCrossCode())
-                .connect(travelEventKeyedStream)
+                .connect(travelEventStream.keyBy(record -> record.getCrossId()))
                 .process(new CalDirectionSecondMetricFunction())
                 .map((MapFunction<DirectionEvalSecondMetric, String>) desm -> {
                     // 将结果实体类，拼接成制表符分割的字符串，进行sink，要保持字段顺序跟表的字段顺序相一致
@@ -65,7 +56,7 @@ public class DirectionEvalJob {
                             + longToStandardFormatString(System.currentTimeMillis()) + "\t" + longToStandardFormatString(System.currentTimeMillis());
                 }).sinkTo(builder.build());
 
-        // 旅行数据流
+        // 实时数据流必备，常驻进程
         env.execute("DirectionEvalJob");
     }
 }