Commons Beanutils example source code file (DoubleArrayConverter.java)

This example Commons Beanutils source code file (DoubleArrayConverter.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Commons Beanutils tags/keywords

abstractarrayconverter, conversionexception, doublearrayconverter, doublearrayconverter, exception, exception, list, model, no, object, object, string, string, util

The Commons Beanutils DoubleArrayConverter.java source code

/*
 * 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.beanutils.converters;


import java.util.List;
import org.apache.commons.beanutils.ConversionException;


/**
 * <p>Standard {@link org.apache.commons.beanutils.Converter} implementation that converts an incoming
 * String into a primitive array of double.  On a conversion failure, returns
 * a specified default value or throws a {@link ConversionException} depending
 * on how this instance is constructed.</p>
 *
 * @author Craig R. McClanahan
 * @version $Revision: 556229 $ $Date: 2007-07-14 07:11:19 +0100 (Sat, 14 Jul 2007) $
 * @since 1.4
 * @deprecated Replaced by the new {@link ArrayConverter} implementation
 */

public final class DoubleArrayConverter extends AbstractArrayConverter {


    // ----------------------------------------------------------- Constructors


    /**
     * Create a {@link org.apache.commons.beanutils.Converter} that will throw
     * a {@link ConversionException} if a conversion error occurs.
     */
    public DoubleArrayConverter() {

        this.defaultValue = null;
        this.useDefault = false;

    }


    /**
     * Create a {@link org.apache.commons.beanutils.Converter} that will return
     * the specified default value if a conversion error occurs.
     *
     * @param defaultValue The default value to be returned
     */
    public DoubleArrayConverter(Object defaultValue) {

        this.defaultValue = defaultValue;
        this.useDefault = true;

    }


    // ------------------------------------------------------- Static Variables


    /**
     * <p>Model object for type comparisons.

     */
    private static final double[] MODEL = new double[0];


    // --------------------------------------------------------- Public Methods


    /**
     * Convert the specified input object into an output object of the
     * specified type.
     *
     * @param type Data type to which this value should be converted
     * @param value The input value to be converted
     * @return the converted value
     * @exception ConversionException if conversion cannot be performed
     *  successfully
     */
    public Object convert(Class type, Object value) {

        // Deal with a null value
        if (value == null) {
            if (useDefault) {
                return (defaultValue);
            } else {
                throw new ConversionException("No value specified");
            }
        }

        // Deal with the no-conversion-needed case
        if (MODEL.getClass() == value.getClass()) {
            return (value);
        }

        // Deal with input value as a String array
        if (strings.getClass() == value.getClass()) {
            try {
                String[] values = (String[]) value;
                double[] results = new double[values.length];
                for (int i = 0; i < values.length; i++) {
                    results[i] = Double.parseDouble(values[i]);
                }
                return (results);
            } catch (Exception e) {
                if (useDefault) {
                    return (defaultValue);
                } else {
                    throw new ConversionException(value.toString(), e);
                }
            }
        }

        // Parse the input value as a String into elements
        // and convert to the appropriate type
        try {
            List list = parseElements(value.toString());
            double[] results = new double[list.size()];
            for (int i = 0; i < results.length; i++) {
                results[i] = Double.parseDouble((String) list.get(i));
            }
            return (results);
        } catch (Exception e) {
            if (useDefault) {
                return (defaultValue);
            } else {
                throw new ConversionException(value.toString(), e);
            }
        }

    }


}