Why is there a class with entity name plus an underscore for JPA entity class

Question

I am new to JPA, I have created a class like the following

/**
 * 
 */
package programme;

import javax.persistence.Access;
import javax.persistence.AccessType;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
import javax.persistence.Transient;

/**
 * @author anoop
 *
 */
@Entity
@Table(name="course")
@Access(AccessType.FIELD)
public class programme {
    @Id private int id;
    private String name;
    private int year;
    @Transient private String comments;

    //getters and setters for the fields.
}

I noted that there is another class with name as my entity java class Programme.java with an underscore i.e. Programme_.java. What is this class and why is this generated. Is there any way that I can stop its generation?

the code for the Programme_.java class is as following.

package programme;

import javax.annotation.Generated;
import javax.persistence.metamodel.SingularAttribute;
import javax.persistence.metamodel.StaticMetamodel;

@Generated(value="Dali", date="2014-04-27T21:32:59.433+0530")
@StaticMetamodel(programme.class)
public class programme_ {
    public static volatile SingularAttribute<programme, Integer> id;
    public static volatile SingularAttribute<programme, String> name;
    public static volatile SingularAttribute<programme, Integer> year;
    public static volatile SingularAttribute<programme, String> comments;
}

Answer 1

This is your "Canonical Metamodel". It can be used with the JPA Criteria API, as described by the JPA 2.x spec (Section 6.2).

To stop Eclipse from generating these classes: edit your Eclipse project properties > JPA > Canonical metamodel (JPA 2.0) > Source folder - set the folder's value to "".