How to map PostgreSQL enum with JPA and Hibernate

Question

I am trying to map a PostgreSQL custom type,named transmission_result, to a Hibernate/JPA POJO. The PostgreSQL custom type is more or less an enum type of string values.

I have created a custom EnumUserType called PGEnumUserType as well as an enum class representing the PostgreSQL enumerated values. When I run this against a real database, I receive the following error:

'ERROR: column "status" is of type transmission_result but expression is of type
character varying 
  Hint: You will need to rewrite or cast the expression.
  Position: 135 '

Upon seeing this, I figured I needed to change my SqlTypes to Types.OTHER. But doing so breaks my integration tests (using HyperSQL in memory DB) with the message:

'Caused by: java.sql.SQLException: Table not found in statement
[select enrollment0_."id" as id1_47_0_,
 enrollment0_."tpa_approval_id" as tpa2_47_0_,
 enrollment0_."tpa_status_code" as tpa3_47_0_,
 enrollment0_."status_message" as status4_47_0_,
 enrollment0_."approval_id" as approval5_47_0_,
 enrollment0_."transmission_date" as transmis6_47_0_,
 enrollment0_."status" as status7_47_0_,
 enrollment0_."transmitter" as transmit8_47_0_
 from "transmissions" enrollment0_ where enrollment0_."id"=?]'

I'm not sure why changing the sqlType results in this error. Any help is appreciated.

JPA/Hibernate Entity:

@Entity
@Access(javax.persistence.AccessType.PROPERTY)
@Table(name="transmissions")
public class EnrollmentCycleTransmission {

// elements of enum status column
private static final String ACCEPTED_TRANSMISSION = "accepted";
private static final String REJECTED_TRANSMISSION = "rejected";
private static final String DUPLICATE_TRANSMISSION = "duplicate";
private static final String EXCEPTION_TRANSMISSION = "exception";
private static final String RETRY_TRANSMISSION = "retry";

private Long transmissionID;
private Long approvalID;
private Long transmitterID;
private TransmissionStatusType transmissionStatus;
private Date transmissionDate;
private String TPAApprovalID;
private String TPAStatusCode;
private String TPAStatusMessage;


@Column(name = "id")
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
public Long getTransmissionID() {
    return transmissionID;
}

public void setTransmissionID(Long transmissionID) {
    this.transmissionID = transmissionID;
}

@Column(name = "approval_id")
public Long getApprovalID() {
    return approvalID;
}

public void setApprovalID(Long approvalID) {
    this.approvalID = approvalID;
}

@Column(name = "transmitter")
public Long getTransmitterID() {
    return transmitterID;
}

public void setTransmitterID(Long transmitterID) {
    this.transmitterID = transmitterID;
}

@Column(name = "status")
@Type(type = "org.fuwt.model.PGEnumUserType" , parameters ={@org.hibernate.annotations.Parameter(name = "enumClassName",value = "org.fuwt.model.enrollment.TransmissionStatusType")} )
public TransmissionStatusType getTransmissionStatus() {
    return this.transmissionStatus ;
}

public void setTransmissionStatus(TransmissionStatusType transmissionStatus) {
    this.transmissionStatus = transmissionStatus;
}

@Column(name = "transmission_date")
public Date getTransmissionDate() {
    return transmissionDate;
}

public void setTransmissionDate(Date transmissionDate) {
    this.transmissionDate = transmissionDate;
}

@Column(name = "tpa_approval_id")
public String getTPAApprovalID() {
    return TPAApprovalID;
}

public void setTPAApprovalID(String TPAApprovalID) {
    this.TPAApprovalID = TPAApprovalID;
}

@Column(name = "tpa_status_code")
public String getTPAStatusCode() {
    return TPAStatusCode;
}

public void setTPAStatusCode(String TPAStatusCode) {
    this.TPAStatusCode = TPAStatusCode;
}

@Column(name = "status_message")
public String getTPAStatusMessage() {
    return TPAStatusMessage;
}

public void setTPAStatusMessage(String TPAStatusMessage) {
    this.TPAStatusMessage = TPAStatusMessage;
}
}

Custom EnumUserType:

public class PGEnumUserType implements UserType, ParameterizedType {

private Class<Enum> enumClass;

public PGEnumUserType(){
    super();
}

public void setParameterValues(Properties parameters) {
    String enumClassName = parameters.getProperty("enumClassName");
    try {
        enumClass = (Class<Enum>) Class.forName(enumClassName);
    } catch (ClassNotFoundException e) {
        throw new HibernateException("Enum class not found ", e);
    }

}

public int[] sqlTypes() {
    return new int[] {Types.VARCHAR};
}

public Class returnedClass() {
    return enumClass;
}

public boolean equals(Object x, Object y) throws HibernateException {
    return x==y;
}

public int hashCode(Object x) throws HibernateException {
    return x.hashCode();
}

public Object nullSafeGet(ResultSet rs, String[] names, Object owner) throws HibernateException, SQLException {
    String name = rs.getString(names[0]);
    return rs.wasNull() ? null: Enum.valueOf(enumClass,name);
}

public void nullSafeSet(PreparedStatement st, Object value, int index) throws HibernateException, SQLException {
    if (value == null) {
        st.setNull(index, Types.VARCHAR);
    }
    else {
        st.setString(index,((Enum) value).name());
    }
}

public Object deepCopy(Object value) throws HibernateException {
    return value;
}

public boolean isMutable() {
    return false;  //To change body of implemented methods use File | Settings | File Templates.
}

public Serializable disassemble(Object value) throws HibernateException {
    return (Enum) value;
}

public Object assemble(Serializable cached, Object owner) throws HibernateException {
    return cached;
}

public Object replace(Object original, Object target, Object owner) throws HibernateException {
    return original;
}

public Object fromXMLString(String xmlValue) {
    return Enum.valueOf(enumClass, xmlValue);
}

public String objectToSQLString(Object value) {
    return '\'' + ( (Enum) value ).name() + '\'';
}

public String toXMLString(Object value) {
    return ( (Enum) value ).name();
}
}

Enum class:

public enum TransmissionStatusType {
accepted,
rejected,
duplicate,
exception,
retry}

Answer 1

I figured it out. I needed to use setObject instead of setString in the nullSafeSet function and pass in the Types.OTHER as the java.sql.type to let jdbc know that it was a postgres type.

public void nullSafeSet(PreparedStatement st, Object value, int index) throws HibernateException, SQLException {
    if (value == null) {
        st.setNull(index, Types.VARCHAR);
    }
    else {
//            previously used setString, but this causes postgresql to bark about incompatible types.
//           now using setObject passing in the java type for the postgres enum object
//            st.setString(index,((Enum) value).name());
        st.setObject(index,((Enum) value), Types.OTHER);
    }
}