- 新建类
package test01;import jdk.nashorn.internal.runtime.regexp.joni.Config;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.configuration.Configuration;
import org.apache.flink.streaming.api.datastream.DataStream;
import org.apache.flink.streaming.api.datastream.DataStreamSource;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;public class TestUnion {public static void main(String[] args) throws Exception {StreamExecutionEnvironment executionEnvironment = StreamExecutionEnvironment.getExecutionEnvironment(new Configuration());executionEnvironment.setParallelism(1);//Union合并流的流数据类型必须一致，如果不一致，需要在合并前先转换类型，使其一致//创建要合并的流DataStreamSource<String> stream1 = executionEnvironment.fromElements("a", "b", "c");DataStreamSource<String> stream2 = executionEnvironment.fromElements("aa", "bb", "cc");DataStreamSource<String> stream3 = executionEnvironment.fromElements("aaa", "bbb", "ccc");//方式一：多次调用union//DataStream<String> union = stream1.union(stream2).union(stream3);//方式二：一次调用，中间用逗号隔开DataStream<String> union = stream1.union(stream2, stream3);union.print();executionEnvironment.execute();}
}
- 运行程序
方式一：
方式二：
