title: Steps for creating Group Validation Using Hibernate Validation
body: <p>I don't really understand the steps for creating Group Validation using Hibernate. Please can anyone help. I have two classes from databases where some fields from both classes should be grouped and validated, using official hibernate docs I take next steps:
  Lets assume I have two classes with fields:</p>
  
  <pre><code>    public class Tickets implements Serializable {
      @NotNull(groups=GroupLotsAndTicketsValidation.class)
      @Size(groups = GroupLotsAndTicketsValidation.class)
      @NotBlank
      private string Amount;
      //and other fields..
      //getters and setters
      }
  </code></pre>
  
  <p>This was my first class. Here is the Second:</p>
  
  <pre><code>public class Lots implements Serializable {
  
  @NotNull(groups = GroupLotsAndTicketsValidation.class)
  @Size(groups = GroupLotsAndTicketsValidation.class)
  @NotBlank(groups =GroupLotsAndTicketsValidation.class)
  private String title;
  @NotNull(groups = GroupLotsAndTicketsValidation.class)
  @NotBlank(groups =GroupLotsAndTicketsValidation.class)
  private String fullWeight;
  //and other fields..
  //getters and setters...
      }
  </code></pre>
  
  <p>This was My second class. 
  Also I read that I should create one interface per class. However as I think It should be done if i want to create my own annotations. 
  Should I create interfaces and what steps to take next. Thanks in advance</p>