Flink详细笔记(四) Flink实时任务入门程序WordCount

本节目录

1 DataFLow编程模型

2 创建Maven项目 搭建Flink开发环境

3 java版WordCount

4 Scala版WordCount

5 运行监控

6 windows和linux开启网络端口监听服务

1 DataFLow编程模型

    Flink基本概念：数据流编程模型（DataFlow Programming Model）

       Dataflow计算模型：希望从编程模型的源头上，统一解决传统的流式和批量这两种计算语意所希望处理的问题。

Flink 提供了不同级别的编程抽象，通过调用抽象的数据集用算子构建 DataFlow 就可以实现对分布式的数据进行流式计算和离线计算。DataSet是批处理的抽象数据集，DataStream是流式计算的抽象数据集，他们的方法都分别是Source、Transformation、Sink .

Source：主要负责数据的读取（即：数据的来源）
Transformation：主要负责对数据的转换操作
Sink：负责最终计算好的结果数据的输出

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2 创建Maven项目 搭建Flink开发环境

<?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>doit-flink</artifactId>
    <version>1.0-SNAPSHOT</version>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <flink.version>1.9.1</flink.version>
        <scala.binary.version>2.11</scala.binary.version>
        <scala.version>2.11.12</scala.version>
    </properties>

    <dependencies>
        <!-- Apache Flink dependencies -->
        <!-- These dependencies are provided, because they should not be packaged into the JAR file. -->
        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-scala_${scala.binary.version}</artifactId>
            <version>${flink.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-streaming-scala_${scala.binary.version}</artifactId>
            <version>${flink.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-core</artifactId>
            <version>${flink.version}</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.apache.flink/flink-scala -->
        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-scala_2.11</artifactId>
            <version>1.9.1</version>
        </dependency>

        <!-- Scala Library, provided by Flink as well. -->
        <dependency>
            <groupId>org.scala-lang</groupId>
            <artifactId>scala-library</artifactId>
            <version>${scala.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-jdbc_2.12</artifactId>
            <version>1.7.2</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.46</version>
        </dependency>


        <!-- Add connector dependencies here. They must be in the default scope (compile). -->

        <!-- Example:

        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-connector-kafka-0.10_${scala.binary.version}</artifactId>
            <version>${flink.version}</version>
        </dependency>
        -->

        <!-- Add logging framework, to produce console output when running in the IDE. -->
        <!-- These dependencies are excluded from the application JAR by default. -->
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.7.7</version>
            <scope>runtime</scope>
        </dependency>

        <!-- https://mvnrepository.com/artifact/log4j/log4j -->
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>


    </dependencies>

    <build>
        <plugins>
            <!-- We use the maven-shade plugin to create a fat jar that contains all necessary dependencies. -->
            <!-- Change the value of <mainClass>...</mainClass> if your program entry point changes. -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-shade-plugin</artifactId>
                <version>3.0.0</version>
                <executions>
                    <!-- Run shade goal on package phase -->
                    <execution>
                        <phase>package</phase>
                        <goals>
                            <goal>shade</goal>
                        </goals>
                        <configuration>
                            <artifactSet>
                                <excludes>
                                    <exclude>org.apache.flink:force-shading</exclude>
                                    <exclude>com.google.code.findbugs:jsr305</exclude>
                                    <exclude>org.slf4j:*</exclude>
                                    <exclude>log4j:*</exclude>
                                </excludes>
                            </artifactSet>
                            <filters>
                                <filter>
                                    <!-- Do not copy the signatures in the META-INF folder.
                                    Otherwise, this might cause SecurityExceptions when using the JAR. -->
                                    <artifact>*:*</artifact>
                                    <excludes>
                                        <exclude>META-INF/*.SF</exclude>
                                        <exclude>META-INF/*.DSA</exclude>
                                        <exclude>META-INF/*.RSA</exclude>
                                    </excludes>
                                </filter>
                            </filters>
                            <transformers>
                                <transformer
                                        implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                                    <mainClass>com._51doit.StreamingJob</mainClass>
                                </transformer>
                            </transformers>
                        </configuration>
                    </execution>
                </executions>
            </plugin>

            <!-- Java Compiler -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.1</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>

            <!-- Scala Compiler -->
            <plugin>
                <groupId>net.alchim31.maven</groupId>
                <artifactId>scala-maven-plugin</artifactId>
                <version>3.2.2</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>compile</goal>
                            <goal>testCompile</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>

            <!-- Eclipse Scala Integration -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-eclipse-plugin</artifactId>
                <version>2.8</version>
                <configuration>
                    <downloadSources>true</downloadSources>
                    <projectnatures>
                        <projectnature>org.scala-ide.sdt.core.scalanature</projectnature>
                        <projectnature>org.eclipse.jdt.core.javanature</projectnature>
                    </projectnatures>
                    <buildcommands>
                        <buildcommand>org.scala-ide.sdt.core.scalabuilder</buildcommand>
                    </buildcommands>
                    <classpathContainers>
                        <classpathContainer>org.scala-ide.sdt.launching.SCALA_CONTAINER</classpathContainer>
                        <classpathContainer>org.eclipse.jdt.launching.JRE_CONTAINER</classpathContainer>
                    </classpathContainers>
                    <excludes>
                        <exclude>org.scala-lang:scala-library</exclude>
                        <exclude>org.scala-lang:scala-compiler</exclude>
                    </excludes>
                    <sourceIncludes>
                        <sourceInclude>**/*.scala</sourceInclude>
                        <sourceInclude>**/*.java</sourceInclude>
                    </sourceIncludes>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>build-helper-maven-plugin</artifactId>
                <version>1.7</version>
                <executions>
                    <!-- Add src/main/scala to eclipse build path -->
                    <execution>
                        <id>add-source</id>
                        <phase>generate-sources</phase>
                        <goals>
                            <goal>add-source</goal>
                        </goals>
                        <configuration>
                            <sources>
                                <source>src/main/scala</source>
                            </sources>
                        </configuration>
                    </execution>
                    <!-- Add src/test/scala to eclipse build path -->
                    <execution>
                        <id>add-test-source</id>
                        <phase>generate-test-sources</phase>
                        <goals>
                            <goal>add-test-source</goal>
                        </goals>
                        <configuration>
                            <sources>
                                <source>src/test/scala</source>
                            </sources>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

    <!-- This profile helps to make things run out of the box in IntelliJ -->
    <!-- Its adds Flink's core classes to the runtime class path. -->
    <!-- Otherwise they are missing in IntelliJ, because the dependency is 'provided' -->
    <profiles>
        <profile>
            <id>add-dependencies-for-IDEA</id>

            <activation>
                <property>
                    <name>idea.version</name>
                </property>
            </activation>

            <dependencies>
                <dependency>
                    <groupId>org.apache.flink</groupId>
                    <artifactId>flink-scala_${scala.binary.version}</artifactId>
                    <version>${flink.version}</version>
                    <scope>compile</scope>
                </dependency>
                <dependency>
                    <groupId>org.apache.flink</groupId>
                    <artifactId>flink-streaming-scala_${scala.binary.version}</artifactId>
                    <version>${flink.version}</version>
                    <scope>compile</scope>
                </dependency>
                <dependency>
                    <groupId>org.scala-lang</groupId>
                    <artifactId>scala-library</artifactId>
                    <version>${scala.version}</version>
                    <scope>compile</scope>
                </dependency>
            </dependencies>
        </profile>
    </profiles>


</project>

3 java版WordCount

/**
 * @Auther: 多易教育-行哥
 * @Date: 2020/6/14
 * @Description:
 */
public class WordCount {
    public static void main(String[] args) throws Exception {
        // 1 创建一个flink处理实时数据的环境
        StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
        // 2 创建datastream ,也就是我们所说的Source数据源
        // 参数一  网络数据源的主机  参数二  端口号 
        DataStreamSource<String> sources = env.socketTextStream("lx01", 8888);
        // 3处理接收的数据  组装成(单词,1)
        SingleOutputStreamOperator<Tuple2<String, Integer>> wordAndOne = sources.flatMap(new FlatMapFunction<String, Tuple2<String, Integer>>() {
            @Override
            public void flatMap(String line, Collector<Tuple2<String, Integer>> collector) throws Exception {
                String[] words = line.split("\\s+");
                for (String word : words) {
                    Tuple2<String, Integer> tp = Tuple2.of(word, 1);
                    collector.collect(tp);
                }
            }
        });
          //4 安装单词分组  将分组后的单词的个数累加
        SingleOutputStreamOperator<Tuple2<String, Integer>> res = wordAndOne.keyBy(0).sum(1);
        //5  打印结果
        res.print() ;
        env.execute("java_flink-stream-word_count") ;
    }
}

4 Scala版WordCount

/**
 * @Auther: 多易教育-行哥
 * @Date: 2020/6/14 
 * @Description:
 */
object ScalaWordCount {
  def main(args: Array[String]): Unit = {
    // 使用scala的API开发flink代码需要导入scala
    import org.apache.flink.api.scala._
    // 创建实时处理对象
    val env: StreamExecutionEnvironment = StreamExecutionEnvironment.getExecutionEnvironment
    // 数据源设置为 网络流
    val ds: DataStream[String] = env.socketTextStream("lx01", 8888, '\n', 200)
    // 处理每行数据 切割 组装 累加
    val ds2: DataStream[(String, Int)] = ds.flatMap(_.split("\\s+")).map((_, 1)).keyBy(0).sum(1)
    // 打印结果 
    ds2.print()
    // 执行
    env.execute("scala-flink-word_count")

  }
}

5 运行监控

nc -lk 8888  启动网络客户端输入内容  [root@lx01 ~]# nc -lk 8888

运行程序 在idea中直接运行 控制台打印内容 

6 windows和linux开启网络端口监听服务

6.1 windows

   Windows本身是不支持 nc 端口监听的。但是我们可以通过下载 netcat 来是解决这个问题。下载地址：netcat

  下载后，进行解压，并将解压后目录下的所有文(.txt 文件除外)，复制到 C:\Windows\System32 目录下，我们便可以在 cmd 命令行使用 nc 命令了。

       我们通过命令：nc -help可以查看该命令的使用描述。

       使用命令：nc -lp 8888即可开启监听 8888 端口号

6.2 linux

    Linux 开启端口监听，也是使用nc命令，如果出现-bash: nc: command not found，我们通过命令：yum install nc 安装 nc 即可。

       通过命令：nc -help，可以来查看 nc 命令的使用描述。
       使用命令：nc -lk 8888即可开启监听 8888 端口号