de.unentscheidbar.validation.swing.DefaultMessageTextGetter.java Source code

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Here is the source code for de.unentscheidbar.validation.swing.DefaultMessageTextGetter.java

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/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright 1997-2009 Sun Microsystems, Inc. All rights reserved. Portions Copyrighted 2012 Daniel
 * Huss.
 *
 * The contents of this file are subject to the terms of either the GNU General Public License
 * Version 2 only ("GPL") or the Common Development and Distribution License("CDDL") (collectively,
 * the "License"). You may not use this file except in compliance with the License. You can obtain a
 * copy of the License at http://www.netbeans.org/cddl-gplv2.html or nbbuild/licenses/CDDL-GPL-2-CP.
 * See the License for the specific language governing permissions and limitations under the
 * License. When distributing the software, include this License Header Notice in each file and
 * include the License file at nbbuild/licenses/CDDL-GPL-2-CP. Sun designates this particular file
 * as subject to the "Classpath" exception as provided by Sun in the GPL Version 2 section of the
 * License file that accompanied this code. If applicable, add the following below the License
 * Header, with the fields enclosed by brackets [] replaced by your own identifying information:
 * "Portions Copyrighted [year] [name of copyright owner]"
 *
 * Contributor(s):
 *
 * The Original Software is NetBeans. The Initial Developer of the Original Software is Sun
 * Microsystems, Inc. Portions Copyright 1997-2006 Sun Microsystems, Inc. All Rights Reserved.
 *
 * If you wish your version of this file to be governed by only the CDDL or only the GPL Version 2,
 * indicate your decision by adding "[Contributor] elects to include this software in this
 * distribution under the [CDDL or GPL Version 2] license." If you do not indicate a single choice
 * of license, a recipient has the option to distribute your version of this file under either the
 * CDDL, the GPL Version 2 or to extend the choice of license to its licensees as provided above.
 * However, if you add GPL Version 2 code and therefore, elected the GPL Version 2 license, then the
 * option applies only if the new code is made subject to such option by the copyright holder.
 */
package de.unentscheidbar.validation.swing;

import java.io.Serializable;
import java.text.MessageFormat;
import java.util.Locale;
import java.util.MissingResourceException;
import java.util.ResourceBundle;
import java.util.ResourceBundle.Control;

import javax.annotation.Nonnull;
import javax.annotation.concurrent.Immutable;

import org.apache.commons.lang3.ClassUtils;

import de.unentscheidbar.validation.ValidationMessage;
import de.unentscheidbar.validation.ValidationMessage.Id;

@Immutable
final class DefaultMessageTextGetter implements MessageTextGetter, Serializable {

    private static final long serialVersionUID = Validation.VERSION;

    static final MessageTextGetter INSTANCE = new DefaultMessageTextGetter();

    /**
     * Reads and formats a message from a resource bundle that is named "Messages" and lives in the
     * same package as the class of the message ID (obtained using {@link #getClass()}).
     * <p>
     * Examples:<br/>
     * <ul>
     * <li>Message ID {@code org.netbeans.validation.SampleValidator$Id} uses resource bundle with
     * base name "org.netbeans.validation.Messages"</li>
     * <li>Class {@code org.netbeans.validation.AnotherValidatorId} also uses resource bundle with
     * base name "org.netbeans.validation.Messages"</li>
     * <li>Class {@code HelloWorld} (in default namespace) uses resource bundle with base name
     * "Messages"</li>
     * </ul>
     * </p>
     * <p>
     * Note: This method returs the string value of the message ID in case no bundle or message is
     * found instead of throwing {@link MissingResourceException}.
     * </p>
     *
     * @param message
     *            The message containing an identifier and message details (formatting parameters).
     * @param locale
     *            The locale to use when looking up resource bundles. If {@code null}, defaults to
     *            the default display locale.
     * @return Formatted message.
     */
    @Override
    public @Nonnull CharSequence getMessageText(ValidationMessage message, Locale locale) {

        try {
            return MessageFormat.format(getFormatString(message.id(), locale), message.details().toArray());
        } catch (MissingResourceException e) {
            return message.id().toString();
        }
    }

    private String getBundleName(ValidationMessage.Id messageId) {

        String bundleName = ClassUtils.getPackageName(messageId.getClass());
        bundleName = bundleName.isEmpty() ? "Messages" : bundleName + ".Messages";
        return bundleName;
    }

    private String getFormatString(ValidationMessage.Id messageId, Locale locale) throws MissingResourceException {

        ResourceBundle bundle = ResourceBundle.getBundle(getBundleName(messageId), locale,
                messageId.getClass().getClassLoader());
        return String.valueOf(bundle.getObject(messageId.name()));
    }

    private static class StrictControl extends Control implements Serializable {

        @Override
        public Locale getFallbackLocale(String baseName, Locale locale) {

            return null;
        }
    }

    private static final DefaultMessageTextGetter.StrictControl STRICT_CONTROL = new StrictControl();

    @Override
    public boolean hasText(Id messageId, Locale locale) {

        try {
            String bundleName = getBundleName(messageId);
            ResourceBundle bundle = ResourceBundle.getBundle(bundleName, locale,
                    messageId.getClass().getClassLoader(), STRICT_CONTROL);
            Object resource = bundle.getObject(messageId.name());
            return resource != null;
        } catch (MissingResourceException e) {
            return false;
        }
    }
}