Could not initialize class org.eclipse.persistence.jaxb.BeanValidationHelper while trying to get JSON response
<p>I am making application using JAVA EE,JAX-RS,JPA,GLASSFISH. Response is working properly in case of <strong>MediaType.APPLICATION_XML</strong>. It's not working in <strong>MediaType.APPLICATION_JSON</strong>.</p>

<p>Here is my pojo class </p>

<pre><code>@Entity
@XmlRootElement
public class Book {
    private int id;
    private String name;
    private String publication;
    private String price;

    @Id
    @Column(name = "id")
    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    @Basic
    @Column(name = "name")
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @Basic
    @Column(name = "publication")
    public String getPublication() {
        return publication;
    }

    public void setPublication(String publication) {
        this.publication = publication;
    }

    @Basic
    @Column(name = "price")
    public String getPrice() {
        return price;
    }

    public void setPrice(String price) {
        this.price = price;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;

        Book book = (Book) o;

        if (id != book.id) return false;
        if (name != null ? !name.equals(book.name) : book.name != null) return false;
        if (publication != null ? !publication.equals(book.publication) : book.publication != null) return false;
        if (price != null ? !price.equals(book.price) : book.price != null) return false;

        return true;
    }

    @Override
    public int hashCode() {
        int result = id;
        result = 31 * result + (name != null ? name.hashCode() : 0);
        result = 31 * result + (publication != null ? publication.hashCode() : 0);
        result = 31 * result + (price != null ? price.hashCode() : 0);
        return result;
    }
}
</code></pre>

<p>Here is the pom.xml file.</p>

<pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
&lt;project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"&gt;
    &lt;modelVersion&gt;4.0.0&lt;/modelVersion&gt;

    &lt;groupId&gt;com.rajesh&lt;/groupId&gt;
    &lt;artifactId&gt;Library&lt;/artifactId&gt;
    &lt;version&gt;1.0-SNAPSHOT&lt;/version&gt;
    &lt;packaging&gt;war&lt;/packaging&gt;

    &lt;dependencies&gt;
        &lt;dependency&gt;
            &lt;groupId&gt;javax&lt;/groupId&gt;
            &lt;artifactId&gt;javaee-api&lt;/artifactId&gt;
            &lt;version&gt;7.0&lt;/version&gt;
            &lt;scope&gt;provided&lt;/scope&gt;
        &lt;/dependency&gt;

        &lt;dependency&gt;
            &lt;groupId&gt;mysql&lt;/groupId&gt;
            &lt;artifactId&gt;mysql-connector-java&lt;/artifactId&gt;
            &lt;version&gt;5.1.6&lt;/version&gt;
        &lt;/dependency&gt;
    &lt;/dependencies&gt;
    &lt;build&gt;
        &lt;plugins&gt;
            &lt;plugin&gt;
                &lt;artifactId&gt;maven-war-plugin&lt;/artifactId&gt;
                &lt;version&gt;2.6&lt;/version&gt;
                &lt;configuration&gt;
                    &lt;failOnMissingWebXml&gt;false&lt;/failOnMissingWebXml&gt;
                &lt;/configuration&gt;
            &lt;/plugin&gt;
        &lt;/plugins&gt;
    &lt;/build&gt;
&lt;/project&gt;
</code></pre>

<p>Resource class for endpoint</p>

<pre><code>@Path("books")
public class BookResource {
    @GET
    @Path("{bookId}")
    @Produces({MediaType.APPLICATION_JSON})
    public Response getBookById(@PathParam("bookId") int id) {
        EntityManagerFactory entityManagerFactory = Persistence.createEntityManagerFactory("abc");
        EntityManager entityManager = entityManagerFactory.createEntityManager();
        Book book = entityManager.find(Book.class, id);
        if (book == null) {
            return Response.status(Response.Status.NOT_FOUND).build();
        }
        return Response.status(Response.Status.OK).entity(book).build();
    }
}
</code></pre>