flink-csv

• 1. 所需依賴

    <dependency>
      <groupId>org.apache.flink</groupId>
      <artifactId>flink-table</artifactId>
      <version>1.9.0</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.apache.flink/flink-table-api-java-bridge -->
    <dependency>
      <groupId>org.apache.flink</groupId>
      <artifactId>flink-table-api-java-bridge_2.11</artifactId>
      <version>1.9.0</version>
    </dependency>
    <dependency>
      <groupId>org.apache.flink</groupId>
      <artifactId>flink-table-planner_2.11</artifactId>
      <version>1.9.0</version>
      <scope>provided</scope>
    </dependency>

• 2.flink讀取csv文件，並使用table api創建邏輯表，使用sql進行操作

/**
 * 讀取csv文件  並使用table api創建邏輯表  進行查詢
 */
public class CsvSource {
    public static void main(String[] args) throws Exception {
        ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
        DataSet<Student> csvInput = env.readCsvFile("C:\\Users\\Lenovo\\Desktop\\test.csv")
                //設置要讀取的屬性列   1爲讀   0爲不讀
                .includeFields("10010")
                //忽略第一行  (忽略表頭)
                .ignoreFirstLine()
                //指定對應的實體類型                 //指定對應的屬性名
                .pojoType(Student.class,"name","score");
        //使用table api創建邏輯表
        BatchTableEnvironment tableEnv = BatchTableEnvironment.create(env);
        Table table = tableEnv.fromDataSet(csvInput);
        tableEnv.registerTable("test_flink",table);
        //執行sql查詢
        Table result = tableEnv.sqlQuery("select * from test_flink where name = 'suns1'");
        //輸出結果
        DataSet<Student> doubleDataSet = tableEnv.toDataSet(result, Student.class);
        doubleDataSet.print();
    }
    ```