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feilong is a suite of core and expanded libraries that include utility classes, http, excel,cvs, io classes, and much much more.
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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 com.feilong.lib.beanutils.converters;

/**
 * {@link com.feilong.lib.beanutils.Converter} implementaion that handles conversion
 * to and from java.lang.Class objects.
 * 
 * The class will be loaded from the thread context class
 * loader (if it exists); otherwise the class loader that loaded this class
 * will be used.
 * 

 * Can be configured to either return a default value or throw a
 * ConversionException if a conversion error occurs.
 *
 * @version $Id$
 * @since 1.4
 */
public final class ClassConverter extends AbstractConverter{

    /**
     * Construct a java.lang.Class Converter that throws
     * a ConversionException if an error occurs.
     */
    public ClassConverter(){
        super();
    }

    /**
     * Construct a java.lang.Class Converter that returns
     * a default value if an error occurs.
     *
     * @param defaultValue
     *            The default value to be returned
     *            if the value to be converted is missing or an error
     *            occurs converting the value.
     */
    public ClassConverter(final Object defaultValue){
        super(defaultValue);
    }

    /**
     * Return the default type this Converter handles.
     *
     * @return The default type this Converter handles.
     * @since 1.8.0
     */
    @Override
    protected Class getDefaultType(){
        return Class.class;
    }

    /**
     * 

     * Convert a java.lang.Class or object into a String.
     * 
     *
     * @param value
     *            The input value to be converted
     * @return the converted String value.
     * @since 1.8.0
     */
    @Override
    protected String convertToString(final Object value){
        return (value instanceof Class) ? ((Class) value).getName() : value.toString();
    }

    /**
     * 
     * Convert the input object into a java.lang.Class.
     * 
     *
     * @param 
     *            Target type of the conversion.
     * @param type
     *            Data type to which this value should be converted.
     * @param value
     *            The input value to be converted.
     * @return The converted value.
     * @throws Throwable
     *             if an error occurs converting to the specified type
     * @since 1.8.0
     */
    @Override
    protected  T convertToType(final Class type,final Object value) throws Throwable{
        if (Class.class.equals(type)){
            ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
            if (classLoader != null){
                try{
                    return type.cast(classLoader.loadClass(value.toString()));
                }catch (final ClassNotFoundException ex){
                    // Don't fail, carry on and try this class's class loader
                    // (see issue# BEANUTILS-263)
                }
            }

            // Try this class's class loader
            classLoader = ClassConverter.class.getClassLoader();
            return type.cast(classLoader.loadClass(value.toString()));
        }

        throw conversionException(type, value);
    }

}