Hibernate usertype for getting/setting a custom value instead of using @Enumerated(EnumType.STRING) or @Enumerated(EnumType.Ordinal)
UserType source:
package example.usertype;
import java.io.Serializable;
import java.lang.reflect.Method;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Properties;
import org.hibernate.HibernateException;
import org.hibernate.type.NullableType;
import org.hibernate.type.TypeFactory;
import org.hibernate.usertype.ParameterizedType;
import org.hibernate.usertype.UserType;
/**
* generic enum user type based on: http://www.hibernate.org/272.html
*
* @param enumClass
* @param identifierMethod
* @param valueOfMethod
*/
public class GenericEnumUserType implements UserType, ParameterizedType {
private static final String DEFAULT_IDENTIFIER_METHOD_NAME = "name";
private static final String DEFAULT_VALUE_OF_METHOD_NAME = "valueOf";
@SuppressWarnings("unchecked")
private Class<? extends Enum> enumClass;
private Class<?> identifierType;
private Method identifierMethod;
private Method valueOfMethod;
private NullableType type;
private int[] sqlTypes;
public void setParameterValues(Properties parameters) {
String enumClassName = parameters.getProperty("enumClass");
try {
enumClass = Class.forName(enumClassName).asSubclass(Enum.class);
} catch (ClassNotFoundException cfne) {
throw new HibernateException("Enum class not found", cfne);
}
String identifierMethodName = parameters.getProperty(
"identifierMethod", DEFAULT_IDENTIFIER_METHOD_NAME);
try {
identifierMethod = enumClass.getMethod(identifierMethodName,
new Class[0]);
identifierType = identifierMethod.getReturnType();
} catch (Exception e) {
throw new HibernateException("Failed to obtain identifier method",
e);
}
type = (NullableType) TypeFactory.basic(identifierType.getName());
if (type == null)
throw new HibernateException("Unsupported identifier type "
+ identifierType.getName());
sqlTypes = new int[] { type.sqlType() };
String valueOfMethodName = parameters.getProperty("valueOfMethod",
DEFAULT_VALUE_OF_METHOD_NAME);
try {
valueOfMethod = enumClass.getMethod(valueOfMethodName,
new Class[] { identifierType });
} catch (Exception e) {
throw new HibernateException("Failed to obtain valueOf method", e);
}
}
@SuppressWarnings("unchecked")
public Class returnedClass() {
return enumClass;
}
public Object nullSafeGet(ResultSet rs, String[] names, Object owner)
throws HibernateException, SQLException {
Object identifier = type.get(rs, names[0]);
if (identifier == null) {
return null;
}
// fix for fixed length char datatype (db2)
if (identifier instanceof String) {
identifier = ((String) identifier).trim();
}
Object value;
try {
value = valueOfMethod
.invoke(enumClass, new Object[] { identifier });
} catch (Exception e) {
throw new HibernateException(
"Exception while invoking valueOf method '"
+ valueOfMethod.getName() + "' of "
+ "enumeration class '" + enumClass + "'", e);
}
if (value == null) {
throw new HibernateException(
"Impossible to translate identifier-value '" + identifier
+ "' to enum of type '" + enumClass + "'");
}
return value;
}
public void nullSafeSet(PreparedStatement st, Object value, int index)
throws HibernateException, SQLException {
if (value == null) {
st.setNull(index, type.sqlType());
} else {
Object identifier;
try {
identifier = identifierMethod.invoke(value, new Object[0]);
} catch (Exception e) {
throw new HibernateException(
"Exception while invoking identifierMethod '"
+ identifierMethod.getName() + "' of "
+ "enumeration class '" + enumClass + "'", e);
}
if (identifier == null) {
throw new HibernateException(
"Disallowed to update/insert null identifier-value for non-null enum-value of type '"
+ enumClass + "'");
}
type.set(st, identifier, index);
}
}
public int[] sqlTypes() {
return sqlTypes;
}
public Object assemble(Serializable cached, Object owner)
throws HibernateException {
return cached;
}
public Object deepCopy(Object value) throws HibernateException {
return value;
}
public Serializable disassemble(Object value) throws HibernateException {
return (Serializable) value;
}
public boolean equals(Object x, Object y) throws HibernateException {
return x == y;
}
public int hashCode(Object x) throws HibernateException {
return x.hashCode();
}
public boolean isMutable() {
return false;
}
public Object replace(Object original, Object target, Object owner)
throws HibernateException {
return original;
}
}
Enum source:
package example.model;
import java.util.EnumSet;
import java.util.HashMap;
import java.util.Map;
public enum Direction {
INCOMING('I'), //
OUTGOING('O'); //
private static final Map<Character, Direction> idMap = new HashMap<Character, Direction>();
static {
for (Direction direction : EnumSet.allOf(Direction.class)) {
idMap.put(direction.getId(), direction);
}
}
private final Character id;
private Direction(Character id) {
this.id = id;
}
public static Direction valueById(Character id) {
return idMap.get(id);
}
public Character getId() {
return id;
}
}
Usage:
@Type(type = "example.usertype.GenericEnumUserType", parameters = {
@Parameter(name = "enumClass", value = "example.model.Direction"),
@Parameter(name = "identifierMethod", value = "getId"),
@Parameter(name = "valueOfMethod", value = "valueById") })
@Column(name = "DIRECTION", nullable = false, length = 1)
public Direction getDirection() {
return this.direction;
}
public void setDirection(Direction direction) {
this.direction = direction;
}
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