/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.commons.math.util;

import java.io.Serializable;

import org.apache.commons.math.MathException;

/**
 * A Default NumberTransformer for java.lang.Numbers and Numeric Strings. This
 * provides some simple conversion capabilities to turn any java.lang.Number
 * into a primitive double or to turn a String representation of a Number into a
 * double.
 *
 * @version $Revision$ $Date$
 */
public class DefaultTransformer implements NumberTransformer, Serializable {
	// TODO: Add Serializable documentation
	// TODO: Check Serializable implementation

	/** Serializable version identifier */
	private static final long serialVersionUID = 4019938025047800455L;

	/**
	 * @param o
	 *            the object that gets transformed.
	 * @return a double primitive representation of the Object o.
	 * @throws org.apache.commons.math.MathException
	 *             If it cannot successfully be transformed or is null.
	 * @see <a href=
	 *      "http://commons.apache.org/collections/api-release/org/apache/commons/collections/Transformer.html"/>
	 */
	public double transform(Object o) throws MathException {

		if (o == null) {
			throw new MathException("Conversion Exception in Transformation, Object is null");
		}

		if (o instanceof Number) {
			return ((Number) o).doubleValue();
		}

		try {
			return Double.valueOf(o.toString()).doubleValue();
		} catch (Exception e) {
			throw new MathException(e, "Conversion Exception in Transformation: {0}", e.getMessage());
		}
	}
}
