Store enums in database using hibernate - mysql

Question

I need to store an object using Hibernate, but this object use an enum. I can store, but when I tried to retrieve it again, this fails with this error: "Studies is not mapped [FROM Studies]".
I tried with a lot of solutions in internet but nothing works. I use MySQL database
This is the enum:
public enum StudyStatus {
Created("Created"), Started("Started"), Closed("Closed");
private final String value;
StudyStatus(String value){
this.value = value;
}
public static StudyStatus fromValue(int value){
for (StudyStatus status : values()) {
if (status.value.equals(value)) {
return status;
}
}
throw new IllegalArgumentException("Invalid status: " + value);
}
public String toValue(){
return value;
}
}
This is the EnumUserType class
import java.io.Serializable;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Types;
import java.util.Properties;
import org.hibernate.HibernateException;
import org.hibernate.engine.spi.SessionImplementor;
import org.hibernate.type.AbstractStandardBasicType;
import org.hibernate.type.IntegerType;
import org.hibernate.type.StringType;
import org.hibernate.usertype.EnhancedUserType;
import org.hibernate.usertype.ParameterizedType;
public abstract class AbstractEnumUserType<E extends Enum<E>, V> implements
EnhancedUserType, ParameterizedType {
public static int DEAFAULT_SQL_TYPE = Types.INTEGER;
private PreparedStatementSetter psSetter;
private AbstractStandardBasicType<?> basicType;
protected abstract Class<E> getEnumClass();
protected abstract Class<V> getValueClass();
protected abstract E convertEnum(V rawValue);
protected abstract V convertSqlValue(E enumValue);
protected int getSqlType() {
int sqlType = Types.OTHER;
switch (getValueClass().getName()) {
case "java.lang.String":
sqlType = Types.VARCHAR;
break;
case "java.lang.Integer":
sqlType = Types.INTEGER;
break;
default:
break;
}
return sqlType;
}
// ////////////////////////////
#Override
public int[] sqlTypes() {
return new int[] { getSqlType() };
}
#Override
public Class<?> returnedClass() {
return getEnumClass();
}
#Override
public boolean equals(Object x, Object y) throws HibernateException {
return (x == y);
}
#Override
public int hashCode(Object x) throws HibernateException {
return (x == null) ? 0 : x.hashCode();
}
#Override
public Object nullSafeGet(ResultSet rs, String[] names,
SessionImplementor session, Object owner)
throws HibernateException, SQLException {
Object rawValue = basicType.nullSafeGet(rs, names[0], session, owner);
Object enumValue = (rawValue == null) ? null
: convertEnum((V) rawValue);
return enumValue;
}
#Override
public void nullSafeSet(PreparedStatement st, Object value, int index,
SessionImplementor session) throws HibernateException, SQLException {
if (value == null) {
st.setNull(index, Types.VARCHAR);
} else {
psSetter.set(st, convertSqlValue((E) value), index);
}
}
#Override
public Object deepCopy(Object value) throws HibernateException {
return value;
}
#Override
public boolean isMutable() {
return false;
}
#Override
public Serializable disassemble(Object value) throws HibernateException {
return (Serializable) value;
}
#Override
public Object assemble(Serializable cached, Object owner)
throws HibernateException {
return cached;
}
#Override
public Object replace(Object original, Object target, Object owner)
throws HibernateException {
return original;
}
#Override
public void setParameterValues(Properties parameters) {
// Initialize Method
initBasicType();
initPreparedStatementSetter();
}
#Override
public String objectToSQLString(Object value) {
return '\'' + ((Enum<?>) value).name() + '\'';
}
#Override
public String toXMLString(Object value) {
return ((Enum<?>) value).name();
}
#Override
public Object fromXMLString(String xmlValue) {
// TODO
throw new IllegalAccessError();
// return Enum.valueOf(, xmlValue);
}
protected void initBasicType() {
switch (getSqlType()) {
case Types.VARCHAR:
basicType = StringType.INSTANCE;
break;
case Types.INTEGER:
basicType = IntegerType.INSTANCE;
break;
default:
break;
}
}
protected void initPreparedStatementSetter() {
// TODO
switch (getSqlType()) {
case Types.VARCHAR:
psSetter = new StringPreparedStatementSetter();
break;
case Types.INTEGER:
psSetter = new IntPreparedStatementSetter();
default:
break;
}
}
private static interface PreparedStatementSetter {
void set(PreparedStatement st, Object value, int index)
throws SQLException;
}
private static class StringPreparedStatementSetter implements
PreparedStatementSetter {
#Override
public void set(PreparedStatement st, Object value, int index) {
try {
st.setString(index, (String) value);
} catch (SQLException e) {
}
}
}
private static class IntPreparedStatementSetter implements
PreparedStatementSetter {
#Override
public void set(PreparedStatement st, Object value, int index) {
try {
st.setInt(index, (Integer) value);
} catch (SQLException e) {
}
}
}
}
The class with the enum
import java.util.ArrayList;
import ateam.capi.common.enums.StudyStatus;
public class Study {
private String id;
private String name;
private StudyStatus status;
private ArrayList<User> pollsters;
private Questionnaire actualQuestionnaire;
public Questionnaire getActualQuestionnaire() {
return actualQuestionnaire;
}
public void setActualQuestionnaire(Questionnaire actualQuestionnaire) {
this.actualQuestionnaire = actualQuestionnaire;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public StudyStatus getStatus() {
return status;
}
public void setStatus(StudyStatus status) {
this.status = status;
}
public ArrayList<User> getPollsters() {
return pollsters;
}
public void setPollsters(ArrayList<User> pollsters) {
this.pollsters = pollsters;
}
}
This is the XML to map the Study class
<hibernate-mapping package="ateam.capi.common.beans">
<class name="Study" table="Studies">
<id name="id" column="id"></id>
<property name="name"/>
<property name="status">
<type name="ateam.capi.capipersistence.utils.EnumUserType">
<param name="enumClassName">
ateam.capi.common.enums.StudyStatus
</param>
</type>
</property>
</class>
</hibernate-mapping>
Study DAO class
import java.util.List;
import org.hibernate.HibernateException;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.Transaction;
import ateam.capi.capipersistence.utils.HibernateUtil;
import ateam.capi.common.beans.Questionnaire;
import ateam.capi.common.beans.Study;
public class DAO_Study {
private Session session;
private Transaction tx;
public void saveStudy(Study study) throws HibernateException{
try{
initOperations();
session.save(study);
tx.commit();
} catch (HibernateException ex){
handleException(ex);
throw ex;
} finally{
if (session!=null){
session.close();
}
}
}
public void deleteStudy(Study study) throws HibernateException{
try{
initOperations();
this.session.delete(study);
this.tx.commit();
} catch (HibernateException ex){
handleException(ex);
throw ex;
} finally{
if (session!=null){
session.close();
}
}
}
public List<Study> getStudiesList() throws HibernateException{
List<Study> studiesList = null;
try{
initOperations();
String hql = "FROM Studies";
Query query = session.createQuery(hql);
studiesList = query.list();
} catch (HibernateException ex){
handleException(ex);
throw ex;
} finally{
if (session!=null){
session.close();
}
}
return studiesList;
}
private void initOperations() throws HibernateException{
HibernateUtil.createSession();
this.session = HibernateUtil.getSessionFactory().openSession();
this.tx = this.session.beginTransaction();
}
private void handleException(HibernateException ex) throws HibernateException{
this.tx.rollback();
System.out.println(ex.getStackTrace());
throw ex;
}
}
I use Java7 with hibernate 4.1.8, I found other solutions but dont work in java7
Any Idea?
Thanks!

Answer 1

Shouldn't your query look like from study instead of from studies? Studies is the table not the defined entity.