DoubleConverterFactory.java

/*****************************************************************************
 * Copyright 2011 Zdenko Vrabel
 *
 * Licensed 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.zdevra.guice.mvc.converters;

import java.lang.annotation.Annotation;
import java.util.Map;

import org.zdevra.guice.mvc.ConversionService.Converter;
import org.zdevra.guice.mvc.ConversionService.ConverterFactory;

/**
 * The factory creates a converter which provide conversion of double values
 */
public class DoubleConverterFactory implements ConverterFactory {

    private final static Converter<Double> typeConverter = new DoubleConverter();
    private final static Converter<Double[]> objArrayConverter = new DoubleObjArrayConverter();
    private final static Converter<double[]> arrayConverter = new DoubleArrayConverter();

    /**
     * {@inheritDoc}
     *
     * @param type
     * @param annotations
     * @return
     */
    @Override
    public Converter<?> createConverter(Class<?> type, Annotation[] annotations) {
        if ((type == Double.class) || (type == double.class)) {
            return typeConverter;
        } else if (type == Double[].class) {
            return objArrayConverter;
        } else if (type == double[].class) {
            return arrayConverter;
        }

        return null;
    }


    /**
     * Nested converted that convert string to doubles
     */
    private static class DoubleConverter extends TypeConverter<Double> {

        @Override
        protected Double convertType(String stringValue) {
            return Double.parseDouble(stringValue);
        }
    }

    /**
     * Nested converted for conversion of doubles array
     */
    private static class DoubleArrayConverter implements Converter<double[]> {

        @Override
        public double[] convert(String name, Map<String, String[]> data) {
            String[] values = data.get(name);
            if (values == null) {
                return new double[]{};
            }

            double[] out = new double[values.length];
            for (int i = 0; i < values.length; ++i) {
                out[i] = Double.parseDouble(values[i]);
            }
            return out;
        }
    }

    /**
     * Nested converted for conversion of doubles array
     */
    private static class DoubleObjArrayConverter implements Converter<Double[]> {

        @Override
        public Double[] convert(String name, Map<String, String[]> data) {
            String[] values = data.get(name);
            if (values == null) {
                return new Double[]{};
            }

            Double[] out = new Double[values.length];
            for (int i = 0; i < values.length; ++i) {
                out[i] = Double.parseDouble(values[i]);
            }
            return out;
        }
    }
}