Hibernate hql return object

In Hibernate hql, I want to return Ojbect from hql,

public class HqlReturnObject  implements  Serializable{ 
    String domain;
    String id;
    Object obj;

    public HqlReturnObject() {
        //super();
    }

    public HqlReturnObject(String domain, String id, Object obj) {      
        this.domain = domain;
        this.id = id;
        this.obj = obj;
    }
    ......
}

String hql = "select new HqlReturnObject('order',salesOrderId,  document) from  ... ";  
this.getHibernateTemplate().find(hql); 

      

        
        
        
      

    

mistake

    java.lang.NullPointerException
at org.hibernate.util.ReflectHelper.getConstructor(ReflectHelper.java:172)
    at org.hibernate.hql.ast.tree.ConstructorNode.resolveConstructor(ConstructorNode.java:114)
    at org.hibernate.hql.ast.tree.ConstructorNode.prepare(ConstructorNode.java:88)

      

        
        
        
      

    

but I have defined a constructor in HqlReturnObject.

thank