enumtype.java

jbpm-bpel-1.1.Beta3 JBoss jBPM Starters Kit 是一个综合包

/*
 * JBoss, Home of Professional Open Source
 * Copyright 2005, JBoss Inc., and individual contributors as indicated
 * by the @authors tag.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the JBPM BPEL PUBLIC LICENSE AGREEMENT as
 * published by JBoss Inc.; either version 1.0 of the License, or
 * (at your option) any later version.
 *
 * This software 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.
 */
package org.jbpm.bpel.db.type;

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.apache.commons.lang.enums.Enum;
import org.apache.commons.lang.enums.EnumUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.hibernate.HibernateException;
import org.hibernate.usertype.ParameterizedType;
import org.hibernate.usertype.UserType;

/**
 * @author Juan Cantu
 * @version $Revision: 1.3 $ $Date: 2006/09/27 03:53:01 $
 */
public class EnumType implements UserType, ParameterizedType {

  private Class enumClass;

  /**
   * Enumeration class parameter name.
   */
  public static final String ENUM_CLASS_PARAM = "class";

  private static final int[] SQL_TYPES = { Types.VARCHAR };
  private static final Log log = LogFactory.getLog(EnumType.class);

  public boolean equals(Object o1, Object o2) {
    return o1 == null ? o2 == null : o1.equals(o2);
  }

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

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

  public boolean isMutable() {
    return false;
  }

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

  public Object assemble(Serializable s, Object o) throws HibernateException {
    return s;
  }

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

  public int[] sqlTypes() {
    return SQL_TYPES;
  }

  public Object nullSafeGet(ResultSet rs, String[] names, Object owner)
      throws HibernateException, SQLException {
    // get enum constant name
    final String columnName = names[0];
    String enumName = rs.getString(columnName);
    // resolve enum constant
    Enum enumConstant = enumName != null ? EnumUtils.getEnum(enumClass,
        enumName) : null;
    if (log.isTraceEnabled())
      log.trace("returning '" + enumConstant + "' as column: " + columnName);
    return enumConstant;
  }

  public void nullSafeSet(PreparedStatement st, Object value, int index)
      throws HibernateException, SQLException {
    if (value == null) {
      st.setNull(index, SQL_TYPES[0]);
      if (log.isTraceEnabled())
        log.trace("binding null to parameter: " + index);
    }
    else {
      final String enumName = ((Enum) value).getName();
      st.setString(index, enumName);
      if (log.isTraceEnabled())
        log.trace("binding '" + enumName + "' to parameter: " + index);
    }
  }

  public Class returnedClass() {
    return enumClass;
  }

  public void setParameterValues(Properties parameters)
      throws HibernateException {
    try {
      enumClass = Class.forName((String) parameters.get(ENUM_CLASS_PARAM));
    }
    catch (ClassNotFoundException e) {
      throw new HibernateException(e);
    }
  }
}