Commons Beanutils example source code file (ClassConverter.java)

This example Commons Beanutils source code file (ClassConverter.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

abstractconverter, abstractconverter, class, class, classconverter, classconverter, classloader, classnotfoundexception, object, object, string, throwable

The Commons Beanutils ClassConverter.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;

/**
 * {@link org.apache.commons.beanutils.Converter} implementaion that handles conversion
 * to and from <b>java.lang.Class objects.
 * <p>
 * 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.
 * <p>
 * Can be configured to either return a <i>default value or throw a
 * <code>ConversionException if a conversion error occurs.
 *
 * @author Tomas Viberg
 * @version $Revision: 690380 $ $Date: 2008-08-29 21:04:38 +0100 (Fri, 29 Aug 2008) $
 * @since 1.4
 */
public final class ClassConverter extends AbstractConverter {

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

    /**
     * Construct a <b>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(Object defaultValue) {
        super(defaultValue);
    }

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

    /**
     * <p>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
     */
    protected String convertToString(Object value) {
        return (value instanceof Class) ? ((Class)value).getName() : value.toString();
    }

    /**
     * <p>Convert the input object into a java.lang.Class.

     *
     * @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
     */
    protected Object convertToType(Class type, Object value) throws Throwable {
        ClassLoader classLoader =
            Thread.currentThread().getContextClassLoader();
        if (classLoader != null) {
            try {
                return (classLoader.loadClass(value.toString()));
            } catch (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 (classLoader.loadClass(value.toString()));
    }

}