Getting class cast exception when doing a POST request using JAX-RS with hibernate backend - jax-rs

Question

I have a simple User POJO class, its definition is as follows:
package models;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;
import javax.persistence.UniqueConstraint;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
#Entity
#XmlRootElement
#Table(name="USER",uniqueConstraints={#UniqueConstraint(columnNames="email")})
public class User {
#XmlElement
private String name;
#Id
#XmlElement
#GeneratedValue(strategy=GenerationType.IDENTITY)
private int id;
#XmlElement
private String email;
#XmlElement
private int age;
#Override
public String toString() {
return "User [name=" + name + ", id=" + id + ", email=" + email + ", age=" + age + "]";
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}
and my resource mapping is as follows:
#POST
#Produces(MediaType.TEXT_HTML)
#Consumes(MediaType.APPLICATION_JSON)
#Path("/Person")
public Response insertPerson(User user) {
SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();
Session session = sessionFactory.openSession();
Transaction tx = session.beginTransaction();
int uid = (Integer)session.save(user);
tx.commit();
session.close();
return Response.status(201).entity(uid).build();
}
When i do a post request using PostMan i am getting this exception on server:
Dec 20, 2015 9:44:42 AM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [Jersey Web Application] in context with path [/expenseManagement] threw exception [Exception [EclipseLink-6065] (Eclipse Persistence Services - 2.6.0.v20150309-bf26070): org.eclipse.persistence.exceptions.QueryException
Exception Description: Cannot add the object [User [name=manjunath, id=100, email=manjunath#gmail.com, age=15]], of class [class models.User], to container [class models.User].
Internal Exception: java.lang.ClassCastException: models.User cannot be cast to java.util.Collection] with root cause
java.lang.ClassCastException: models.User cannot be cast to java.util.Collection
I have provided message body readers as well, I don't know where i am going wrong, can someone please help.

Answer 1

The content you send is surrounded by [ and ] marking it an array, not an object. Try sending only this String:
{"name":"manjunath", "age":15, "id":100, "email":"manjunath#gmail.com"}
Good Luck