ccc.plugins.persistence.hibernate.EnumUserType.java Source code

Introduction

Here is the source code for ccc.plugins.persistence.hibernate.EnumUserType.java

Source

/*-----------------------------------------------------------------------------
 * Copyright (c) 2008 Civic Computing Ltd.
 * All rights reserved.
 *
 * This file is part of Content Control.
 *
 * Content Control is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Content Control is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Content Control.  If not, see http://www.gnu.org/licenses/.
 *
 * Revision      $Rev$
 * Modified by   $Author$
 * Modified on   $Date$
 *
 * Changes: see subversion log.
 *-----------------------------------------------------------------------------
 */
package ccc.plugins.persistence.hibernate;

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.usertype.ParameterizedType;
import org.hibernate.usertype.UserType;

/**
 * A hibernate user type that can persist a Java 5 enum.
 *
 * @param <T> The type of the enum to persist.
 *
 * @author Civic Computing Ltd.
 */
public class EnumUserType<T extends Enum<T>> implements UserType, ParameterizedType, Serializable {

    /** PROPERTY_TYPE : String. */
    static final String PROPERTY_TYPE = "type";

    private Class<T> _enumClass;

    /**
     * Constructor.
     *
     * @param enumClass The enum this user type represents.
     */
    EnumUserType(final Class<T> enumClass) {
        _enumClass = enumClass;
    }

    /**
     * Constructor.
     */
    public EnumUserType() {
        super();
    }

    /** {@inheritDoc} */
    @SuppressWarnings("unchecked") // Class class doesn't support generics
    @Override
    public void setParameterValues(final Properties parameters) {
        final String enumClassName = parameters.getProperty(PROPERTY_TYPE);
        try {
            _enumClass = (Class<T>) Class.forName(enumClassName);
        } catch (final Exception cnfe) {
            throw new HibernateException("Enum class not found: " + enumClassName, cnfe);
        }
    }

    /** {@inheritDoc} */
    @Override
    public Object assemble(final Serializable cached, final Object owner) {
        return cached;
    }

    /** {@inheritDoc} */
    @Override
    public Object deepCopy(final Object value) {
        return value;
    }

    /** {@inheritDoc} */
    @Override
    public Serializable disassemble(final Object value) {
        return (Serializable) value;
    }

    /** {@inheritDoc} */
    @Override
    public boolean equals(final Object x, final Object y) {
        return x == y;
    }

    /** {@inheritDoc} */
    @Override
    public int hashCode(final Object x) {
        return x.hashCode();
    }

    /** {@inheritDoc} */
    @Override
    public boolean isMutable() {
        return false;
    }

    /** {@inheritDoc} */
    @Override
    public T nullSafeGet(final ResultSet rs, final String[] names, final Object owner) throws SQLException {

        final String value = rs.getString(names[0]);
        if (null == value) {
            return null;
        }
        return Enum.valueOf(this._enumClass, value);

    }

    /** {@inheritDoc} */
    @Override
    public void nullSafeSet(final PreparedStatement st, final Object value, final int index) throws SQLException {
        if (value == null) {
            st.setNull(index, Types.VARCHAR);
        } else {
            st.setString(index, _enumClass.cast(value).name());
        }
    }

    /** {@inheritDoc} */
    @Override
    public Object replace(final Object original, final Object target, final Object owner) {
        return original;
    }

    /** {@inheritDoc} */
    @Override
    public Class<T> returnedClass() {
        return _enumClass;
    }

    /** {@inheritDoc} */
    @Override
    public int[] sqlTypes() {
        return new int[] { Types.VARCHAR };
    }

}