org.apache.wicket.util.convert.converter.AbstractConverter.java Source code

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Here is the source code for org.apache.wicket.util.convert.converter.AbstractConverter.java

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/*
 * 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.wicket.util.convert.converter;

import java.text.Format;
import java.text.ParsePosition;
import java.util.Locale;

import org.apache.wicket.util.convert.ConversionException;
import org.apache.wicket.util.convert.IConverter;

/**
 * Base class for locale aware type converters.
 * 
 * @author Eelco Hillenius
 * @param <C>
 */
public abstract class AbstractConverter<C> implements IConverter<C> {
    private static final long serialVersionUID = 1L;

    /**
     * Parses a value using one of the java.util.text format classes.
     * 
     * @param format
     *            The format to use
     * @param value
     *            The object to parse
     * @param locale
     *            The locale to use to parse.
     * @return The object
     * @throws ConversionException
     *             Thrown if parsing fails
     */
    @SuppressWarnings("unchecked")
    protected C parse(final Format format, final Object value, final Locale locale) {
        final ParsePosition position = new ParsePosition(0);
        final String stringValue = value.toString();
        final C result = (C) format.parseObject(stringValue, position);

        if (position.getIndex() != stringValue.length()) {
            throw newConversionException("Cannot parse '" + value + "' using format " + format, value, locale)
                    .setFormat(format);
        }
        return result;
    }

    /**
     * Creates a conversion exception for throwing
     * 
     * @param message
     *            The message
     * @param value
     *            The value that didn't convert
     * @param locale
     *            The locale
     * @return The ConversionException
     */
    protected ConversionException newConversionException(final String message, final Object value,
            final Locale locale) {
        return new ConversionException(message).setSourceValue(value).setTargetType(getTargetType())
                .setConverter(this).setLocale(locale);
    }

    /**
     * @return The target type of this type converter
     */
    protected abstract Class<C> getTargetType();

    /**
     * @see org.apache.wicket.util.convert.IConverter#convertToString(java.lang.Object, Locale)
     */
    @Override
    public String convertToString(final C value, final Locale locale) {
        if (value == null) {
            return null;
        }
        return value.toString();
    }
}