需求:
连续两个相同key的数量相差超过10就报警.
import org.apache.flink.api.common.functions.MapFunction; import org.apache.flink.api.common.functions.RichFlatMapFunction; import org.apache.flink.api.common.state.ValueState; import org.apache.flink.api.common.state.ValueStateDescriptor; import org.apache.flink.api.java.tuple.Tuple2; import org.apache.flink.configuration.Configuration; import org.apache.flink.streaming.api.datastream.DataStreamSource; import org.apache.flink.streaming.api.datastream.SingleOutputStreamOperator; import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment; import org.apache.flink.util.Collector; /** * # _*_ coding:utf-8 _*_ * # Author:xiaoshubiao * # Time : 2020/12/11 14:09 **/ public class state_test2 { public static void main(String[] args) throws Exception{ class stateFalg{ String name; long count; } StreamExecutionEnvironment executionEnvironment = StreamExecutionEnvironment.getExecutionEnvironment(); DataStreamSource<String> localhost = executionEnvironment.socketTextStream("localhost", 1111); // 输入a,1这样的数据,计算连续两个相同key的数量差值 // 差值不能大于10 SingleOutputStreamOperator<Tuple2<String, Integer>> map = localhost.map( new MapFunction<String, Tuple2<String, Integer>>() { @Override public Tuple2<String, Integer> map(String s) throws Exception { String[] split = s.split(","); return new Tuple2<>(split[0], Integer.valueOf(split[1])); } } ); map.keyBy(0).flatMap( // 参数1:是输入的数据类型 //参数2:是报警时显示的数据类型 new RichFlatMapFunction<Tuple2<String, Integer>, Tuple2<String,String>>() { ValueState<stateFalg> state1; @Override public void open(Configuration parameters) throws Exception { //创建一个状态值 ValueStateDescriptor<stateFalg> state = new ValueStateDescriptor<>("state", stateFalg.class); state1 = getRuntimeContext().getState(state); } @Override public void flatMap(Tuple2<String, Integer> stringIntegerTuple2, Collector<Tuple2<String, String>> collector) throws Exception { // 判断状态值是否为空(状态默认值是空) if(state1.value() == null){ stateFalg sFalg = new stateFalg(); sFalg.name = stringIntegerTuple2.f0; sFalg.count = stringIntegerTuple2.f1; state1.update(sFalg); } stateFalg value = state1.value(); if(Math.abs(value.count - stringIntegerTuple2.f1)>10){ collector.collect(new Tuple2<String,String>("数量超出警戒值",stringIntegerTuple2.f0)); } value.name = stringIntegerTuple2.f0; value.count = stringIntegerTuple2.f1; // 更新状态值 state1.update(value); } } ).print(); executionEnvironment.execute(); } } /* 输入 输出 a,1 a,20 (数量超出警戒值,a) b,1 b,2 c,1 (数量超出警戒值,a) a,1 c,50 (数量超出警戒值,c) **/
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