Flink 复杂事件处理 [英] Flink Complex Event Processing
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问题描述
我有一个从套接字读取并检测模式的 flink cep 代码.假设模式(词)是警报".如果 alert 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!!
I have a flink cep code that reads from socket and detects for a pattern. Lets say the pattern(word) is 'alert'. If the word alert occurs five times or more, an alert should be created. But I am getting an input mismatch error. Flink version is 1.3.0. Thanks in advance !!
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();
}
}
推荐答案
所以我已经得到了可以工作的代码.这是有效的解决方案,
So I have got the code to work. Here is the working solution,
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();
}
}
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