Flink快速上手
批处理
Maven配置pom文件
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>org.example</groupId>
<artifactId>com.atguigu</artifactId>
<version>1.0-SNAPSHOT</version>
<properties>
<flink.version>1.17.0</flink.version>
</properties>
<dependencies>
<dependency>
<groupId>org.apache.flink</groupId>
<artifactId>flink-streaming-java</artifactId>
<version>${flink.version}</version>
</dependency>
<dependency>
<groupId>org.apache.flink</groupId>
<artifactId>flink-clients</artifactId>
<version>${flink.version}</version>
</dependency>
</dependencies>
</project>java编写wordcount代码
基于DataSet API(过时的,不推荐)
之后用 DataStream API
javascript
package com.atguigu.wc;
import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.operators.AggregateOperator;
import org.apache.flink.api.java.operators.DataSource;
import org.apache.flink.api.java.operators.FlatMapOperator;
import org.apache.flink.api.java.operators.UnsortedGrouping;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.util.Collector;
public class WordCountBatchDemo {
public static void main(String[] args) throws Exception {
//1.创建执行环境
ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
//2.读取数据，从文件中读取
DataSource<String> lineDS = env.readTextFile("input/word.txt");
//3.切分、转换（word，1）
FlatMapOperator<String, Tuple2<String, Integer>> wordAndOne = lineDS.flatMap(new FlatMapFunction<String, Tuple2<String, Integer>>() {
@Override
public void flatMap(String value, Collector<Tuple2<String, Integer>> out) throws Exception {
//Todo3.1 按照空格 切分单词
String[] words = value.split(" ");
//Todo3.2 将单词转换为(word,1)
for (String word : words) {
Tuple2<String, Integer> wordTuple2 = Tuple2.of(word, 1);
//Todo3.3 调用采集器collector 向下游发送数据
out.collect(wordTuple2);
}
}
});
//4.按照word分组
UnsortedGrouping<Tuple2<String, Integer>> wordAndOneGroupBy = wordAndOne.groupBy(0);
//5.各分组内聚合
AggregateOperator<Tuple2<String, Integer>> sum = wordAndOneGroupBy.sum(1);
//6.输出
sum.print();
}
}
有界流处理
javascript
package com.atguigu.wc;
import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.functions.KeySelector;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.streaming.api.datastream.DataStreamSource;
import org.apache.flink.streaming.api.datastream.KeyedStream;
import org.apache.flink.streaming.api.datastream.SingleOutputStreamOperator;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.util.Collector;
public class WordCountStreamDemo {
public static void main(String[] args) throws Exception {
//TODO 1. 创建执行环境
StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
//TODO 2. 读取数据
DataStreamSource<String> lineDS = env.readTextFile("input/word.txt");
//TODO 3. 处理数据:切分/转换/分组/聚合
//TODO 3.1 处理数据:切分/转换
SingleOutputStreamOperator<Tuple2<String, Integer>> wordAndOneDS = lineDS.flatMap(new FlatMapFunction<String, Tuple2<String, Integer>>() {
@Override
public void flatMap(String value, Collector<Tuple2<String, Integer>> out) throws Exception {
//切分
String[] words = value.split(" ");
for (String word : words) {
//转换为二元组（word，1）
Tuple2<String, Integer> wordAndOne = Tuple2.of(word, 1);
//通过采集器 向下游发送数据
out.collect(wordAndOne);
}
}
});
//TODO 3.2 处理数据:分组
KeyedStream<Tuple2<String, Integer>, String> wordAndOneKS = wordAndOneDS.keyBy(
new KeySelector<Tuple2<String, Integer>, String>() {
@Override
public String getKey(Tuple2<String, Integer> value) throws Exception {
return value.f0;
}
});
//TODO 3.3 处理数据:聚合
SingleOutputStreamOperator<Tuple2<String, Integer>> sumDS = wordAndOneKS.sum(1);
//TODO 4. 输出数据
sumDS.print();
//TODO 5. 执行：sparkstreaming 最后 ssc.start()
env.execute();
}
}
无界流处理
事件驱动
javascript
package com.atguigu.wc;
import org.apache.flink.api.common.typeinfo.Types;
import org.apache.flink.api.java.tuple.Tuple2;
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;
public class WordCountSocketStream {
public static void main(String[] args) throws Exception {
//TODO 1. 创建执行环境
StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
DataStreamSource<String> socketDS = env.socketTextStream("hadoop102", 7777);
SingleOutputStreamOperator<Tuple2<String, Integer>> sum = socketDS
.flatMap((String value, Collector<Tuple2<String, Integer>> out) -> {
//切分
String[] words = value.split(" ");
for (String word : words) {
//转换为二元组（word，1）
//通过采集器 向下游发送数据
out.collect(Tuple2.of(word, 1));
}
}
)
.returns(Types.TUPLE(Types.STRING, Types.INT))
.keyBy(value -> value.f0)
.sum(1);
sum.print();
env.execute();
}
}事件触发
来一个处理一个
