Jersey : JSON Unsupported Media Type

Question

I want to create a rest api that get json data and send json data.

My Book class :

@Entity
public class Book {

    @Id
    private String isbn;

    public Book() {
        
    }
......
}

My Book service :

@Path("/books")
public class BookService {

    @POST
    @Consumes(MediaType.APPLICATION_JSON)
    @Produces(MediaType.APPLICATION_JSON)
    public Response buyBook(Book book){
        String isbn = book.getIsbn();
        int number = book.getStock();
   
        return Response.status(Response.Status.OK).entity("OK").build();
    }
......
}

When I try to post this with POSTMAN :

POST /books HTTP/1.1    
Host: localhost:5000    
Content-Type: application/json    
Cache-Control: no-cache    
Postman-Token: 3099cd3a-184a-e442-270a-c118930df2b5    

{    
    "isbn" : "",    
    "title" : "",    
    "author" : "",    
    "stock" : "2"    
}        

My rest API send me this response :

HTTP ERROR 415
Problem accessing /books. Reason:
Unsupported Media Type

---

EDIT: (with pom.xml)

<?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/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>wholesalerservice</groupId>
  <version>1.0-SNAPSHOT</version>
  <artifactId>wholesalerservice</artifactId>
  <dependencies>
    <dependency>
        <groupId>org.glassfish.jersey.containers</groupId>
        <artifactId>jersey-container-servlet</artifactId>
        <version>2.17</version>
    </dependency>
    <dependency>
        <groupId>org.eclipse.jetty</groupId>
        <artifactId>jetty-servlet</artifactId>
        <version>9.2.10.v20150310</version>
    </dependency>
    <dependency>
        <groupId>org.eclipse.jetty</groupId>
        <artifactId>jetty-webapp</artifactId>
        <version>9.2.10.v20150310</version>
    </dependency>
 
    <dependency>
      <groupId>javax.ws.rs</groupId>
      <artifactId>javax.ws.rs-api</artifactId>
      <version>2.0.1</version>
      <scope>provided</scope>
    </dependency>
   
    <dependency>
        <groupId>org.hibernate.ogm</groupId>
        <artifactId>hibernate-ogm-mongodb</artifactId>
        <version>4.1.3.Final</version>
    </dependency>
 
    <dependency>
        <groupId>javax.persistence</groupId>
        <artifactId>persistence-api</artifactId>
        <version>1.0.2</version>
    </dependency>
    <dependency>
      <groupId>org.eclipse.persistence</groupId>
      <artifactId>eclipselink</artifactId>
      <version>2.5.2</version>
    </dependency>
    <dependency>
      <groupId>commons-lang</groupId>
      <artifactId>commons-lang</artifactId>
      <version>2.6</version>
      <type>jar</type>
    </dependency>
  </dependencies>
  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-dependency-plugin</artifactId>
        <version>2.4</version>
        <executions>
          <execution>
            <id>copy-dependencies</id>
            <phase>package</phase>
            <goals><goal>copy-dependencies</goal></goals>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
    <properties>
        <maven.compiler.source>1.7</maven.compiler.source>
        <maven.compiler.target>1.7</maven.compiler.target>
    </properties>
    <name>WholesalerService</name>
</project>

Answer 1

So in order to use JSON to POJO conversion for entity bodies, we need to have a MessageBodyReader (sometimes referred to as providers) to handle the conversion. With Java, Jackson has been the de-facto JSON library for a while, and they offer a module with JAX-RS support, which is the one pointed out by @Nico Müller

<dependency>
    <groupId>com.fasterxml.jackson.jaxrs</groupId>
    <artifactId>jackson-jaxrs-json-provider</artifactId>
    <version>2.5.3</version>
</dependency>

The problem with this is that if we don't configure/register it, the only way it will be discovered is by classpath scanning, which most Jersey applications don't depend on. Instead Jersey offers a wrapper module around this artifacts which wraps it in an auto-discoverable feature (version 2.9+), so we don't need to configure it

<dependency>
    <groupId>org.glassfish.jersey.media</groupId>
    <artifactId>jersey-media-json-jackson</artifactId>
    <version>${jersey2.version}</version> <!-- 2.17 latest as of now -->
</dependency>

If you are using Jersey prior to 2.9, you can always register the feature in your application class

@ApplicationPath("/api")
public class AppConfig extends ResourceConfig {
    public AppConfig() {
        packages("...");
        register(JacksonFeature.class);
    }
}

Or in a web.xml register the feature as a provider class

<init-param>
    <param-name>jersey.config.server.provider.classnames</param-name>
    <param-value>
        org.glassfish.jersey.jackson.JacksonFeature
    </param-value>
</init-param>

Answer 2

Did you include the jackson-jaxrs-json-provider in your project?

<dependency>
    <groupId>com.fasterxml.jackson.jaxrs</groupId>
    <artifactId>jackson-jaxrs-json-provider</artifactId>
    <version>2.5.3</version>
</dependency>

In general: Your Book service is missing title, author and stock which you are trying to post.