title: Submitting spark Jobs over livy using curl
body: <p>I'm submitting spark jobs on a livy (0.6.0) session through Curl </p>
  
  <p>The jobs are a big jar file that extends the Job interface just exactly like this :
  <a href="https://stackoverflow.com/a/49220879/8557851">https://stackoverflow.com/a/49220879/8557851</a></p>
  
  <p>Actually when running this code using this curl command :</p>
  
  <pre><code>curl -X POST -d '{"kind": "spark","files":["/config.json"],"jars":["/myjar.jar"],"driverMemory":"512M","executorMemory":"512M"}' -H "Content-Type: application/json" localhost:8998/sessions/
  </code></pre>
  
  <p>When it comes to the code it is exactly like the answer shown above :</p>
  
  <pre><code>package com.mycompany.test
  import org.apache.livy.{Job, JobContext}
  import org.apache.spark._
  import org.apache.livy.scalaapi._
  
  object Test extends Job[Boolean]{
    override def call(jc: JobContext): Boolean = {
    val sc = jc.sc
    sc.getConf.getAll.foreach(println)
    return true
  }
  </code></pre>
  
  <p>As for the error it is a java Nullpointer exception as shown below </p>
  
  <pre><code>Exception in thread "main" java.lang.NullPointerException
      at org.apache.livy.rsc.driver.JobWrapper.cancel(JobWrapper.java:90)
      at org.apache.livy.rsc.driver.RSCDriver.shutdown(RSCDriver.java:127)
      at org.apache.livy.rsc.driver.RSCDriver.run(RSCDriver.java:356)
      at org.apache.livy.rsc.driver.RSCDriverBootstrapper.main(RSCDriverBootstrapper.java:93)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
      at java.lang.reflect.Method.invoke(Method.java:498)
      at org.apache.spark.deploy.JavaMainApplication.start(SparkApplication.scala:52)
      at org.apache.spark.deploy.SparkSubmit.org$apache$spark$deploy$SparkSubmit$$runMain(SparkSubmit.scala:849)
      at org.apache.spark.deploy.SparkSubmit.doRunMain$1(SparkSubmit.scala:167)
      at org.apache.spark.deploy.SparkSubmit.submit(SparkSubmit.scala:195)
      at org.apache.spark.deploy.SparkSubmit.doSubmit(SparkSubmit.scala:86)
      at org.apache.spark.deploy.SparkSubmit$$anon$2.doSubmit(SparkSubmit.scala:924)
      at org.apache.spark.deploy.SparkSubmit$.main(SparkSubmit.scala:933)
      at org.apache.spark.deploy.SparkSubmit.main(SparkSubmit.scala)
  </code></pre>
  
  <p>as the output excepted is to start running the job in the jar</p>