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

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

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 “”.

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Answer