title: NullPointerException on CrudRepository
body: <p>I have created a repository but when I call my repository it gives a NullPointerException everytime. Can someone help me figure out why?</p>
  
  <p>My repository</p>
  
  <pre><code>@Repository
  public interface WorkflowObjectRepository extends CrudRepository&lt;WorkflowObject, String&gt; {
  
      @Override
      WorkflowObject findOne(String id);
  
      @Override
      void delete(WorkflowObject workflowObject);
  
      @Override
      void delete(String id);
  
      @Override
      WorkflowObject save(WorkflowObject workflowObject);
  
  }
  </code></pre>
  
  <p>My Object </p>
  
  <pre><code>@Data
  @Entity
  @Table(name = "workflowobject")
  public class WorkflowObject {
  
      @GeneratedValue
      @Column(name="id")
      private String id;
  
      @Column(name = "state_name")
      private String stateName;
  
  }
  </code></pre>
  
  <p>My test</p>
  
  <pre><code>public class Test {
  
      @Autowired
      static WorkflowObjectRepository subject;
  
      public static void main(String[] args) {
  
          final WorkflowObject obj = new WorkflowObject();
          obj.setId("maha");
          obj.setStateName("test");
          subject.findOne("maha");
      }
  
  }
  </code></pre>
  
  <p>application.properties</p>
  
  <pre><code>spring.datasource.url=jdbc:postgresql://localhost:5432/vtr?
  autoReconnect=true
  spring.datasource.username=vtr
  spring.datasource.password=vtr
  </code></pre>