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我有一个从套接字读取并检测模式的 flink cep 代码。可以说模式（单词）是“警报”。如果警报一词出现五次或更多次，则应创建警报。但我收到输入不匹配错误。Flink 版本是 1.3.0。提前致谢 ！！

package pattern;

import org.apache.flink.cep.CEP;
import org.apache.flink.cep.PatternStream;
import org.apache.flink.cep.pattern.Pattern;
import org.apache.flink.cep.pattern.conditions.IterativeCondition;
import org.apache.flink.streaming.api.datastream.DataStream;
import org.apache.flink.streaming.api.datastream.DataStreamSource;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.util.Collector;

import java.util.List;
import java.util.Map;

    public class cep {

         public static void main(String[] args) throws Exception {


             StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();

                DataStreamSource<String> dss = env.socketTextStream("localhost", 3005);

                dss.print();

                Pattern<String,String> pattern = Pattern.<String> begin("first")
                        .where(new IterativeCondition<String>() {
                            @Override
                            public boolean filter(String word, Context<String> context) throws Exception {
                                return word.equals("alert");
                            }
                        })
                        .times(5);


                PatternStream<String> patternstream = CEP.pattern(dss, pattern);

                DataStream<String> alerts = patternstream
                        .flatSelect((Map<String,List<String>> in, Collector<String> out) -> {

                            String first = in.get("first").get(0);

                            for (int i = 0; i < 6; i++ ) {

                                out.collect(first);

                            }


                        });

                alerts.print();

                env.execute();

            }

    }

在此处输入图像描述

4

2 回答 2

1

只是对原始问题的一些澄清。在 1.3.0 中，有一个错误使得使用 lambdas 作为参数select/flatSelect变得不可能。

它已在 1.3.1 中修复，因此您的第一个代码版本将适用于 1.3.1。

此外，我认为您误解了times量词。它匹配确切的次数。因此，在您的情况下，它只会在事件完全匹配 3 次而不是 3 次或更多时返回。

于 2017-07-12T08:27:48.103 回答
0

所以我有代码可以工作。这是工作解决方案，

    package pattern;

    import org.apache.flink.cep.CEP;
    import org.apache.flink.cep.PatternSelectFunction;
    import org.apache.flink.cep.PatternStream;
    import org.apache.flink.cep.pattern.Pattern;
    import org.apache.flink.cep.pattern.conditions.IterativeCondition;
    import org.apache.flink.streaming.api.datastream.DataStream;
    import org.apache.flink.streaming.api.datastream.DataStreamSource;
    import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
    import org.apache.flink.util.Collector;

    import java.util.List;
    import java.util.Map;

    public class cep {

         public static void main(String[] args) throws Exception {


             StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();

                DataStreamSource<String> dss = env.socketTextStream("localhost", 3005);

                dss.print();

                Pattern<String,String> pattern = Pattern.<String> begin("first")
                        .where(new IterativeCondition<String>() {
                            @Override
                            public boolean filter(String word, Context<String> context) throws Exception {
                                return word.equals("alert");
                            }
                        })
                        .times(5);

                PatternStream<String> patternstream = CEP.pattern(dss, pattern);

                DataStream<String> alerts = patternstream
                        .select(new PatternSelectFunction<String, String>() {
                            @Override
                            public String select(Map<String, List<String>> in) throws Exception {

                                String first = in.get("first").get(0);

                                if(first.equals("alert")){

                                    return ("5 or more alerts");
                                }
                                else{

                                    return (" ");
                                }
                            }
                        });

                alerts.print();

                env.execute();

            }

    }
于 2017-07-12T05:09:19.573 回答