Empty Entity after data retrieving from MySQL DB

Question

I have the following Entity

import static javax.persistence.GenerationType.IDENTITY;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;
import javax.persistence.UniqueConstraint;

import org.hibernate.annotations.Type;

@Entity
@Table(name = "Privilege", uniqueConstraints = @UniqueConstraint(columnNames = "name"))
public class Privilege implements java.io.Serializable {
private static final long serialVersionUID = 8357379972506504809L;

private Long privilegeId;
private String name;
private String description;

public Privilege() {
}

@Id
@GeneratedValue(strategy = IDENTITY)
@Column(name = "privilegeID", unique = true, nullable = false)
public Long getId() {
    return this.privilegeId;
}

public void setId(Long privilegeId) {
    this.privilegeId = privilegeId;
}


@Column(name = "name", unique = true, length = 45)
public String getName() {
    return this.name;
}

public void setName(String name) {
    this.name = name;
}


@Column(name = "description", length = 65535)
@Type(type="text")
public String getDescription() {
    return this.description;
}

public void setDescription(String description) {
    this.description = description;
}

}

which maps a table in a MySQL DB. I'm trying to retrieve the data though the following QueryDSL code

public Privilege findByName(final String name) throws EntityNotFoundException {
        Privilege workgroupPrivilege = new JPAQuery(getEntityManager())
                .from(privilege)
                .where(privilege.name.eq(name))
                .uniqueResult(privilege);
        if (workgroupPrivilege == null)
            throw new EntityNotFoundException("Cannot find entity "
                    + Privilege.class.getCanonicalName()
                    + " with name <" + name + ">");
        else
            return workgroupPrivilege;
    }

The problem is that the findByName() code returns me an instance of the Privilege Entity object but the data in its fields are null. This means that the Entity-DB Table binding is correctly done (otherwhise I would have had a null Privilege Entity instance).

EDIT:

The web app adds this field to the empty instance of Privilege

handler = org.hibernate.proxy.pojo.javassist.JavassistLazyInitializer@48f52e0b

May this added field be the key to solve the problem?

What can be the problem for you ?

Answer 1

由于延迟加载数据，调试器没有显示任何数据。