import org.apache.spark.SparkConf;
import org.apache.spark.api.java.JavaSparkContext;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import scala.Tuple2;

import java.util.Arrays;

public class Sample {
  private static final Logger LOGGER = LoggerFactory.getLogger(Sample.class);

  public static void main(String[] args) {
    //Stage 1
    new Sample.run("/path");
    //Stage 2
    new Sample.jdbcTest(); 
  }

  public jdbcTest(){
    try {  
      Class.forName("com.mysql.jdbc.Driver");  
      Connection con=DriverManager.getConnection("jdbc:mysql://localhost:3306/sonoo","root","root");  

      Statement stmt=con.createStatement();  
      ResultSet rs=stmt.executeQuery("select * from emp"); 
      ResultSet rs1=stmt.executeQuery("select * from emp_sal");

      while(rs.next())  
        System.out.println(rs.getInt(1)+"  "+rs.getString(2)+"  "+rs.getString(3));  

      con.close();  
    } catch(Exception e){ 
      System.out.println(e);  
    } 
  }

  public void run(String inputFilePath) {
    String master = "local[*]";

    SparkConf conf = new SparkConf()
      .setAppName(Sample.class.getName())
      .setMaster(master);
    JavaSparkContext context = new JavaSparkContext(conf);

    context.textFile(inputFilePath)
      .flatMap(text -> Arrays.asList(text.split(" ")).iterator())
      .mapToPair(word -> new Tuple2<>(word, 1))
      .reduceByKey((a, b) -> a + b)
      .foreach(result -> LOGGER.info(String.format("Word [%s] count [%d].", result._1(), result._2)));
  }
}

rs工作成功。rs1根本不执行。问题是，spark是否真的关心非spark任务，当它们作为spark submit命令的一部分提交时。它真的要等到mysql执行dml等吗。