Apache Flink 1.3.2 BatchTableEnvironment的類型方法的TypeInformation

Question

我嘗試了Apache Flink 1.3.2中的幾個flink translation（）函數：一個來自BatchTableEnvironment，另一個來自StreamTableEnvironment。 該程序給了我錯誤，我迷路了。 下面的程序在運行時引發異常（不知道它需要什么TypeInformation）。 它僅使用應與結果所需的內容完全匹配的類型信息。 但這行不通，有什么幫助嗎？ 我想我提供了所有細節...

import org.apache.flink.api.common.typeinfo.TypeInformation;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.table.api.BatchTableEnvironment;
import org.apache.flink.table.api.Table;
import org.apache.flink.table.api.TableEnvironment;

/**
 *
 * @author Paul Z. Wu Oct 28, 2017
 */
public class TableEnv {

    public static void main(String s[]) throws Exception {
        ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
        BatchTableEnvironment tEnv = TableEnvironment.getTableEnvironment(env);

        DataSet<WC> input = env.fromElements(
                new WC("Hello", 1),
                new WC("Ciao", 1),
                new WC("Hello", 1));

        tEnv.registerDataSetInternal("abc", input);
        Table table = tEnv.scan("abc");

        Table wordCounts = table
                .groupBy("word")
                .select("word, count.sum as count");
        System.out.println(wordCounts.getSchema());
        DataSet<WC> a = tEnv.translate(wordCounts, TypeInformation.of(WC.class));
        a.print();
    }

    public static  class WC {

        public WC(String word, int count) {
            this.word = word;
            this.count = count;
        }

        public WC() {
        } // empty constructor to satisfy POJO requirements

        public String word;
        public int count;
    }

}

例外是：

Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/flink/api/scala/typeutils/CaseClassTypeInfo
    at org.apache.flink.table.codegen.CodeGenUtils$.fieldAccessorFor(CodeGenUtils.scala:236)
    at org.apache.flink.table.codegen.CodeGenerator.org$apache$flink$table$codegen$CodeGenerator$$generateFieldAccess(CodeGenerator.scala:1654)
    at org.apache.flink.table.codegen.CodeGenerator.org$apache$flink$table$codegen$CodeGenerator$$generateInputAccess(CodeGenerator.scala:1602)
    at org.apache.flink.table.codegen.CodeGenerator$$anonfun$23.apply(CodeGenerator.scala:875)
    at org.apache.flink.table.codegen.CodeGenerator$$anonfun$23.apply(CodeGenerator.scala:874)
    at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:245)
    at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:245)
    at scala.collection.IndexedSeqOptimized$class.foreach(IndexedSeqOptimized.scala:33)
    at scala.collection.mutable.ArrayOps$ofInt.foreach(ArrayOps.scala:234)
    at scala.collection.TraversableLike$class.map(TraversableLike.scala:245)
    at scala.collection.mutable.ArrayOps$ofInt.map(ArrayOps.scala:234)
    at org.apache.flink.table.codegen.CodeGenerator.generateConverterResultExpression(CodeGenerator.scala:874)
    at org.apache.flink.table.plan.nodes.CommonScan$class.generatedConversionFunction(CommonScan.scala:57)
    at org.apache.flink.table.plan.nodes.dataset.DataSetScan.generatedConversionFunction(DataSetScan.scala:36)
    at org.apache.flink.table.plan.nodes.dataset.BatchScan$class.convertToInternalRow(BatchScan.scala:48)
    at org.apache.flink.table.plan.nodes.dataset.DataSetScan.convertToInternalRow(DataSetScan.scala:36)
    at org.apache.flink.table.plan.nodes.dataset.DataSetScan.translateToPlan(DataSetScan.scala:65)
    at org.apache.flink.table.api.BatchTableEnvironment.translate(BatchTableEnvironment.scala:350)
    at org.apache.flink.table.api.BatchTableEnvironment.translate(BatchTableEnvironment.scala:329)
    at com.att.ariso.TableEnv.main(TableEnv.java:39)
Caused by: java.lang.ClassNotFoundException: org.apache.flink.api.scala.typeutils.CaseClassTypeInfo
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 20 more
------------------------

Answer 1

需要一個運行時庫flink-scala。