二、编写word count示例代码来初步认识flink及了解 批与流 处理的区别

引入依赖 

        
            org.apache.flink
            flink-java
            1.10.1
        

        
            org.apache.flink
            flink-streaming-java_2.12
            1.10.1
        

批处理代码（未知原因暂时数据没有打印 后续知道了来补充）

package com.robert.flink.wcTest;

import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.util.Collector;

public class FlinkBatchWordCountPrintTest {

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

        //get runtime environment
        ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

        //path of file for test
        String filePath = "D:\word.txt";

        //read content into dataset from file
        DataSet stringDataSet = env.readTextFile(filePath);

        DataSet> sum = stringDataSet.flatMap(new FlatMapFunction>() {

            @Override
            public void flatMap(String value, Collector> collector) {
                String[] words = value.split("");
                for (String word : words) {
                    collector.collect(new Tuple2<>(word, 1));
                }
            }
        }).groupBy(0).sum(1);



        //print content of dataset
        sum.print();

    }

}

 流处理代码（未知原因暂时数据没有打印 后续知道了来补充）

package com.robert.flink.wcTest;

import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.common.typeinfo.Types;
import org.apache.flink.api.java.DataSet;
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.tuple.Tuple2;
import org.apache.flink.streaming.api.datastream.DataStream;
import org.apache.flink.streaming.api.datastream.SingleOutputStreamOperator;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.util.Collector;

public class FlinStreamWordCountPrintTest {

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

        //get runtime environment
        StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();

        //path of file for test
        String filePath = "C:\study\咕泡\mybatis\06.MyBatis原理篇\01.MyBatis应用分析与最佳实践\课堂源码\MyBatis第一天代码\flink\src\main\resources\static\word.txt";

        //read content into dataset from file
        DataStream stringDataSet = env.readTextFile(filePath);


        //count word appeared times
        DataStream> sum = stringDataSet.flatMap((FlatMapFunction>) (value, collector) -> {

            String[] words = value.split(" ");
            for (String word : words) {
                collector.collect(new Tuple2<>(word, 1));
            }
        }).returns(Types.TUPLE(Types.STRING, Types.INT)).keyBy(0).sum(1);

        //print content of dataset
        sum.print();

        env.execute();

    }

}