Flink读写kafka主题，并进行数据清洗

flink参考
flink参考

Datastream程序架构

datastream是flink提供给用户使用的用于进行流计算和批处理的api，是对底层流式计算模型的api封装，便于用户编程
一般流程为：

1. 获得一个执行环境；Executiion Environment
2. 加载/创建初始数据；Source
3. 指定转换数据；Transformation
4. 指定存放计算结果的位置；Sink
5. 触发程序执行；流失计算必须的操作，批处理则不必

maven

<flink.version>1.7.2</flink.version>
<kafka.version>2.0.0</kafka.version>

<dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-scala_2.11</artifactId>
            <version>${flink.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.apache.flink/flink-core -->
        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-core</artifactId>
            <version>${flink.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.apache.flink/flink-streaming-scala -->
        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-streaming-scala_2.11</artifactId>
            <version>${flink.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.apache.flink/flink-clients -->
        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-clients_2.11</artifactId>
            <version>${flink.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.apache.flink/flink-shaded-hadoop-2-uber -->
        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-shaded-hadoop-2-uber</artifactId>
            <version>2.4.1-9.0</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.apache.flink/flink-connector-kafka-0.10 -->
        <!-- https://mvnrepository.com/artifact/org.apache.flink/flink-connector-kafka-0.11 -->
        <dependency>
            <groupId>org.apache.flink</groupId>
            <artifactId>flink-connector-kafka_2.11