title: JPA Transient Annotation and JSON
body: <p>This is a follow up to the following question on the JPA Transient annotation
  <a href="https://stackoverflow.com/questions/2154622/why-does-jpa-have-a-transient-annotation">Why does JPA have a @Transient annotation?</a></p>
  
  <p>I have a transient variable that I do not want to persist and it is marked with the transient annotation.
  However, when I want to produce JSON from my rest controller, this transient variable is not available in the outputted JSON.</p>
  
  <p>The POJO PublicationVO is straight forward with no fancy attributes, just some private attributes (that are persisted) with getters and setters and 1 transient variable.</p>
  
  <pre><code>@RequestMapping(value = { "{publicationId}"}, method = RequestMethod.GET, produces = "application/json")
  @ResponseBody public PublicationVO getPublicationDetailsJSON(@PathVariable(value = "publicationId") Integer publicationId) {
      LOG.info("Entered getPublicationDetailsJSON - publicationId: " + publicationId);
  
      //Call method to get the publicationVO based on publicationId
      PublicationVO publicationVO = publicationServices.getPublicationByIdForRestCalls(publicationId);       
      LOG.info("publicationVO:{}", publicationVO);
  
      LOG.info("Exiting getPublicationDetailsJSON");
      return publicationVO;
  }
  </code></pre>
  
  <p>The PublicationVO is as follows</p>
  
  <pre><code>    package com.trinity.domain.dao;
  
  import java.util.Calendar;
  
  import javax.persistence.Column;
  import javax.persistence.Entity;
  import javax.persistence.FetchType;
  import javax.persistence.GeneratedValue;
  import javax.persistence.GenerationType;
  import javax.persistence.Id;
  import javax.persistence.JoinColumn;
  import javax.persistence.ManyToOne;
  import javax.persistence.Table;
  import javax.persistence.Transient;
  
  import com.fasterxml.jackson.annotation.JsonInclude;
  
  @Entity
  @Table(name = "publication")
  public class PublicationVO {
  
      @Id
      @GeneratedValue(strategy = GenerationType.IDENTITY)
      @Column(name = "id", unique = true, nullable = false)
      private Integer id;    
      @Column(name = "publicationName", unique = false, nullable = false, length = 200)
      private String publicationName;
      @Column(name = "publicationSource", unique = false, nullable = false, length = 45)
      private String publicationSource;
  
      @Column(name = "dateAdded", unique = false, nullable = false)
      private Calendar dateAdded;
  
      @Transient
      private float percentageProcessed;
  
      public Integer getId() {
          return id;
      }
  
      public void setId(Integer id) {
          this.id = id;
      }
  
      public String getPublicationName() {
          return publicationName;
      }
  
      public void setPublicationName(String publicationName) {
          this.publicationName = publicationName;
      }
  
      public String getPublicationSource() {
          return publicationSource;
      }
  
      public void setPublicationSource(String publicationSource) {
          this.publicationSource = publicationSource;
      }
  
      public Calendar getDateAdded() {
          return dateAdded;
      }
  
      public void setDateAdded(Calendar dateAdded) {
          this.dateAdded = dateAdded;
      }
  
      public float getPercentageProcessed() {
          return percentageProcessed;
      }
  
      public void setPercentageProcessed(float percentageProcessed) {
          this.percentageProcessed = percentageProcessed;
      }
  
      @Override
      public String toString() {
          return "PublicationVO [id=" + id + ", publicationName=" + publicationName + ", publicationSource=" + publicationSource + ", dateAdded=" + dateAdded
                  + ", percentageProcessed=" + percentageProcessed + "]";
      }
  }
  </code></pre>
  
  <p>When I see the debug statement for publicationVO in my logs, the transient variable is included in the output but in my client code, the transient variable is not included in the json response.</p>
  
  <p>Any help is greatly appreciated.</p>
  
  <p>Thank you,
  Damien</p>