Question

我正在尝试使用flink的table和sql api作为一个简单的例子，我从文件中读取字符串，将其转换为Tuple2并尝试将其插入表中。这是我的代码。

import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.table.StreamTableEnvironment;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.api.table.Table;
import org.apache.flink.streaming.api.TimeCharacteristic;
import org.apache.flink.streaming.api.datastream.DataStream;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.util.Collector;

public class table_streaming_test
{
    public static void main (String[] args) throws Exception
    {
        StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment(); //create execution environment
        StreamTableEnvironment tEnv= StreamTableEnvironment.getTableEnvironment(env); 
        env.setParallelism(1);
        DataStream<String> datastream_in= env.readTextFile("file:/home/rishikesh/new_workspace1/table_streaming/stocks.txt");
         DataStream<Tuple2<String,Integer>> ds=  datastream_in
             .flatMap(new Splitter());  // transformation flatmap
         Table msg=tEnv.fromDataStream(ds).as("symbol,price");
         Table result = msg.select("symbol ='A'");
         DataStream<String> ds2 =tEnv.toDataStream(result, String.class);
         ds2.print();
         env.execute();
    }
public static class Splitter implements FlatMapFunction<String,     Tuple2<String, Integer>> {
        public void flatMap(String sentence, Collector<Tuple2<String, Integer>> out) throws Exception {
            String[] token= sentence.split(",");
            out.collect(new Tuple2<String, Integer>(token[0],Integer.parseInt(token[1])));
        }
    }
}

错误如下:(发生在第DataStream<String> ds2 =tEnv.toDataStream(result, String.class);行）

log4j:WARN No appenders could be found for logger (org.apache.flink.api.java.typeutils.TypeExtractor).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
Exception in thread "main" java.lang.NoSuchMethodError: org.apache.flink.api.table.Table.<init>(Lorg/apache/flink/api/table/TableEnvironment;Lorg/apache/flink/api/table/plan/logical/LogicalNode;)V
    at org.apache.flink.api.table.StreamTableEnvironment.ingest(StreamTableEnvironment.scala:97)
    at org.apache.flink.api.java.table.StreamTableEnvironment.fromDataStream(StreamTableEnvironment.scala:61)
    at table_streaming_test.main(table_streaming_test.java:87)

包含的Jar文件是：

弗林克-dist_2.10-1.1.3.jar
弗林克-python_2.10-1.1.3.jar
弗林克-table_2.10-1.1.3.jar
的log4j-1.2.17.jar
SLF4J-log4j12-1.7.7.jar
JavaSE的-1.7

的JavaSE-1.7

Answer 1

错误的一个可能原因＆＃34; java.lang.NoSuchMethodError＆＃34;当您使用不同版本的flink时，比您在系统上安装的不同。

对我来说，我有Flink 1.4.2，而我使用的版本是1.3.2。所以我更新了我的pom文件，使其具有相同的版本，并且工作正常。

Answer 2

我认为您需要使用shade插件并按照此步骤解决问题

https://ci.apache.org/projects/flink/flink-docs-release-1.4/monitoring/debugging_classloading.html#resolving-dependency-conflicts-with-flink-using-the-maven-shade-plugin

Flink错误：java.lang.NoSuchMethodError：org.apache.flink.api.table.Table

2 个答案: