title: Integration - Apache Flink + Spring Boot
body: <p>I'm testing the integration between Apache Flink and Spring Boot, to run them on IDE is fine, but when I tried to run on Apache Flink Cluster I had one Exception related to ClassLoader.</p>
  
  <p>The classes are really simple:</p>
  
  <p><strong>BootFlinkApplication</strong></p>
  
  <pre><code>@SpringBootApplication
  @ComponentScan("com.example.demo")
  public class BootFlinkApplication {
  
      public static void main(String[] args) {
          System.out.println("some test");
          SpringApplication.run(BootFlinkApplication.class, args);
      }
  }
  </code></pre>
  
  <p><strong>FlinkTest</strong></p>
  
  <pre><code>@Service
  public class FlinkTest {
      @PostConstruct
      public void init() {
          StreamExecutionEnvironment see = StreamExecutionEnvironment.getExecutionEnvironment();
  
          see.fromElements(1, 2, 3, 4)
              .filter(new RemoveNumber3Filter()).print();
  
          try {
              see.execute();
          } catch (Exception e) {
              System.out.println("Error executing flink job: " + e.getMessage());
          }
      }
  }
  </code></pre>
  
  <p><strong>RemoveNumber3Filter</strong></p>
  
  <pre><code>public class RemoveNumber3Filter implements FilterFunction&lt;Integer&gt; {
  
      @Override
      public boolean filter(Integer i) throws Exception {
          return i != 3;
      }
  
  }
  </code></pre>
  
  <p><strong>Exception:</strong></p>
  
  <pre><code>Caused by: org.apache.flink.runtime.client.JobExecutionException: Job execution failed.
          at org.apache.flink.runtime.jobmanager.JobManager$$anonfun$handleMessage$1$$anonfun$applyOrElse$6.apply$mcV$sp(JobManager.scala:897)
          at org.apache.flink.runtime.jobmanager.JobManager$$anonfun$handleMessage$1$$anonfun$applyOrElse$6.apply(JobManager.scala:840)
          at org.apache.flink.runtime.jobmanager.JobManager$$anonfun$handleMessage$1$$anonfun$applyOrElse$6.apply(JobManager.scala:840)
          at scala.concurrent.impl.Future$PromiseCompletingRunnable.liftedTree1$1(Future.scala:24)
          at scala.concurrent.impl.Future$PromiseCompletingRunnable.run(Future.scala:24)
          at akka.dispatch.TaskInvocation.run(AbstractDispatcher.scala:39)
          at akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask.exec(AbstractDispatcher.scala:415)
          at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)
          at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)
          at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
          at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)
      Caused by: org.apache.flink.streaming.runtime.tasks.StreamTaskException: Cannot load user class: com.example.demo.RemoveNumber3Filter
      ClassLoader info: URL ClassLoader:
          file: '/tmp/blobStore-850f3189-807e-4f8d-a8a6-3bd3c1bd76b4/job_eb93b239080b4d4e09f10f1e3605744d/blob_p-5fd56f3348976c0d333d680fde4a79573c21cd40-48ac0995eee11f38ce3ff4f890102af8' (valid JAR)
      Class not resolvable through given classloader.
          at org.apache.flink.streaming.api.graph.StreamConfig.getStreamOperator(StreamConfig.java:232)
          at org.apache.flink.streaming.runtime.tasks.OperatorChain.createChainedOperator(OperatorChain.java:355)
          at org.apache.flink.streaming.runtime.tasks.OperatorChain.createOutputCollector(OperatorChain.java:282)
          at org.apache.flink.streaming.runtime.tasks.OperatorChain.&lt;init&gt;(OperatorChain.java:126)
          at org.apache.flink.streaming.runtime.tasks.StreamTask.invoke(StreamTask.java:231)
          at org.apache.flink.runtime.taskmanager.Task.run(Task.java:718)
          at java.lang.Thread.run(Thread.java:748)
  </code></pre>