目的：读csv,table/sql输出到csv
环境：jdk8 工具：idea

创建maven项目

引入jar包

  1.    <dependency>
  2.             <groupId>org.apache.flink</groupId>
  3.             <artifactId>flink-java</artifactId>
  4.             <version>1.10.1</version>
  5.         </dependency>
  6.         <dependency>
  7.             <groupId>org.apache.flink</groupId>
  8.             <artifactId>flink-streaming-java_2.12</artifactId>
  9.             <version>1.10.1</version>
  10.         </dependency>
  11.         <dependency>
  12.             <groupId>org.apache.flink</groupId>
  13.             <artifactId>flink-table-planner_2.12</artifactId>
  14.             <version>1.10.1</version>
  15.         </dependency>
  16.         <dependency>
  17.             <groupId>org.apache.flink</groupId>
  18.             <artifactId>flink-table-api-java-bridge_2.12</artifactId>
  19.             <version>1.10.1</version>
  20.         </dependency>
  21.         <dependency>
  22.             <groupId>org.apache.flink</groupId>
  23.             <artifactId>flink-csv</artifactId>
  24.             <version>1.10.1</version>
  25.         </dependency>

代码演示

  1.         StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
  2.         env.setParallelism(1);
  4.         StreamTableEnvironment tableEnv = StreamTableEnvironment.create(env);
  7.         tableEnv.connect(new FileSystem().path("C:\\Users\\Luo\\Desktop\\Table\\src\\main\\resources\\test.csv"))
  8.                 .withFormat(new Csv())
  9.                 .withSchema(new Schema()
  10.                         .field("id", DataTypes.INT())
  11.                         .field("name", DataTypes.STRING())
  12.                 )
  13.                 .createTemporaryTable("inputTable");
  15.         Table table = tableEnv.from("inputTable").select("id,name").filter("id ===1");
  17.         Table table1 = tableEnv.from("inputTable").groupBy("id").select("id,id.count as count");
  20.         Table sql = tableEnv.sqlQuery("select id ,name from inputTable where id=2");
  21.         Table sql1 = tableEnv.sqlQuery("select id, count(id) as cnt from inputTable group by id");
  23.         tableEnv.connect(new FileSystem().path("C:\\Users\\Luo\\Desktop\\Table\\src\\main\\resources\\out.csv"))
  24.                 .withFormat(new Csv())
  25.                 .withSchema(new Schema()
  26.                         .field("id", DataTypes.INT())
  27.                         .field("name", DataTypes.STRING())
  28.                 )
  29.                 .createTemporaryTable("outTable");
  31.         sql.insertInto("outTable");
  33.         env.execute();

输出到文件.rar(4 KB)

  1. resouces 文件夹下产生out.csv文件

注意

  1. 初始是没有out.csv文件的。只能插入,不能撤回和更新插入,需要支持这些模式的场景