Could not initialize class org.eclipse.persistence.jaxb.BeanValidationHelper while trying to get JSON response

问题

I am making application using JAVA EE,JAX-RS,JPA,GLASSFISH. Response is working properly in case of MediaType.APPLICATION_XML. It's not working in MediaType.APPLICATION_JSON.

Here is my pojo class

@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;
    }
}

Here is the pom.xml file.

<?xml version="1.0" encoding="UTF-8"?>
<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">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.rajesh</groupId>
    <artifactId>Library</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>war</packaging>

    <dependencies>
        <dependency>
            <groupId>javax</groupId>
            <artifactId>javaee-api</artifactId>
            <version>7.0</version>
            <scope>provided</scope>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.6</version>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <artifactId>maven-war-plugin</artifactId>
                <version>2.6</version>
                <configuration>
                    <failOnMissingWebXml>false</failOnMissingWebXml>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

Resource class for endpoint

@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();
    }
}

回答1:

This is a bug in Glassfish: https://github.com/javaee/glassfish/issues/21440 It probably won't be fixed, you should switch to http://www.payara.fish/ which is patched and updated version of Glassfish (has even commercial support if needed).

This bug is fixed in Payara.

回答2:

Place the "org.eclipse.persistence.moxy.jar" into $GLASSFISHINSTALL/glassfish/modules

Then restart the glassfish

回答3:

Problem had been occurred due to version of Glassfish 4.1.1.It appears there is a bug in Eclipse Link . I am using Glassfish 4.1.0 for temporary solution.

回答4:

I had the same error, but my mistake was pretty funny. I had my pom.xml pointing to EE7 API as follows:

 <dependency>
        <groupId>javax</groupId>
        <artifactId>javaee-api</artifactId>
        <version>7.0</version>
        <scope>provided</scope>
 </dependency>

Meanwhile, I forgot that Glassfish 4.x implements EE6 not EE7.... I downloaded Eclipse Glassfish 5.1.0 then I was sorted!

来源：https://stackoverflow.com/questions/38743128/could-not-initialize-class-org-eclipse-persistence-jaxb-beanvalidationhelper-whi