JPA Exception- Can not find constructor for <Class> with argument types "[class java.lang.String, class java.lang.String]" to fill data

Question

I use jBoss Fuse 6.1.0 with blueprint DSL with openJPA. I use Container Managed transaction (JTA) and transaction managed by Aspects that handles Commit and Rollback as of now

I have following Classes that are JPA entities.

@Entity
@Table(name="CLIENT")
@NamedQuery(name="Client.findAll", query="SELECT c FROM Client c")
public class Client implements Serializable {
    private static final long serialVersionUID = 1L;

    //Had to add this for avoiding exception. And it works as expected
    //Dummy constructor for JPA - Workaround
    public Client(String s1, String s2){}

    @Column(name="requestid", unique=true,nullable=false)
    private String requestId;

    @Id
    @Column(name="clientid", unique=true, nullable=false, length=128)
    private String clientId;


    @OneToOne(fetch=FetchType.LAZY)
    @JoinColumn(name="REQUESTID", nullable=false)
    private RoccoRequest roccoRequest;

    //bi-directional One-To-Many association to ClientGroup
    @OneToMany(mappedBy="client",fetch=FetchType.LAZY)
    private List<ClientGroup> clientGroups;
....
,...
...
}

---

@Entity
@Embeddable
@Table(name="CLIENTGROUP")
@NamedQuery(name="ClientGroup.findAll", query="SELECT c FROM ClientGroup c")
public class ClientGroup implements Serializable {
    private static final long serialVersionUID = 1L;

    @EmbeddedId
    private ClientGroupPK id;

    @Column(length=32)
    private String type;

    @Column(name="clientid", length=128)
    private String clientId;

    //bi-directional many-to-one association to Client
    @ManyToOne(fetch=FetchType.EAGER)
    @MapsId("clientid")
    @JoinColumn(name="CLIENTID", nullable=true, insertable=false,  updatable=false)
    private Client client;
..
.
.
.
}

---

@Entity
@Table(name="ROCCOREQUEST")
@NamedQuery(name="RoccoRequest.CHECK_EXISISTING_CLIENT_DETAILS",
            query="SELECT r FROM RoccoRequest r JOIN r.client c WHERE c.crmId = :crmId")
public class RoccoRequest implements Serializable {
    private static final long serialVersionUID = 1L;

    @Id
    @Column(name="requestid", unique=true, nullable=false, length=128)
    private String requestId;

@OneToOne(mappedBy="roccoRequest", fetch=FetchType.LAZY, cascade={CascadeType.PERSIST, CascadeType.REMOVE})
    private Client client;
..
..
..

---

CriteriaQuery<Client> criteriaQuery =  criteriaBuilder.createQuery(Client.class);
            Root<Client> clientRoot =  criteriaQuery.from(Client.class);
            //Join the Client table with the RoccoRequest table
            final Join<Client, RoccoRequest> clientRoccoJoin = clientRoot.join(Client_.roccoRequest,JoinType.INNER); 

            final Path<String> _requestStatus = clientRoccoJoin.get(RoccoRequest_.statusCode);
            final Path<String> _requestId = clientRoccoJoin.get(RoccoRequest_.requestId);

            final Predicate _crmIdPredicate = criteriaBuilder.equal(clientRoot.get(Client_.crmId), CRMId);

            criteriaQuery.multiselect(_requestId,_requestStatus);
            criteriaQuery.where(_crmIdPredicate);

            //Get list of details of existing requests for the client with the request type as ACO
            clientDetails = entityManager.createQuery(criteriaQuery).getResultList();

            if(null != clientDetails) for(Client clientDetail : clientDetails){
                StatusBO statusDetails = new StatusBO();
                    statusDetails.setCode((clientDetail.getRoccoRequest().getStatusCode()));
                PreInitiationBO preinitiateDetails = new PreInitiationBO();
                    preinitiateDetails.getCaseHeader().setRequestId(requestId);
                    preinitiateDetails.setStatus(statusDetails);
                exisitngRequestInfo.add(preinitiateDetails);    
            }

I have did some Criteria fetching of the entities. But I'm getting an exception as follows:

Can not find constructor for "class com.xxx.xxx.model.Client" with argument types "[class java.lang.String, class java.lang.String]" to fill data.

Why does JPA expect an argument Constructor? It has anything to do with the association? I tried removing the OneToMany relationship but I still get the error.

Please note that I have added a 2 argument constructor that makes no sense to me. But it works if it's given. log root level has Debug enabled. It has very less information on exception.

Please help.

Answer 1

As JBNizet pointed out, I was making a dumb mistake by adding multiselect with two Strings but was having a CrtieriaQuery of type Client.class.

This can either be solved by removing the multiselect(Not in my case) or by Making the CriteriaQuery and other types with Tuples.class instead of Client.class and loop through the Tuples and get as tuple.get(0) etc.

Problem resolved. Thanks @Neil and @JBNizet