UTF8Control.java

/*
 * 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
 *
 *      https://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.
 */

/*
 * This is not the original file distributed by the Apache Software Foundation
 * It has been modified by the Hipparchus project
 */
package org.hipparchus.exception;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URL;
import java.net.URLConnection;
import java.util.Locale;
import java.util.PropertyResourceBundle;
import java.util.ResourceBundle;

/** Control class loading properties in UTF-8 encoding.
 * <p>
 * This class has been very slightly adapted from BalusC answer to question: <a
 * href="http://stackoverflow.com/questions/4659929/how-to-use-utf-8-in-resource-properties-with-resourcebundle">
 * How to use UTF-8 in resource properties with ResourceBundle</a>.
 * </p>
 */
public class UTF8Control extends ResourceBundle.Control {

    /** Empty constructor.
     * <p>
     * This constructor is not strictly necessary, but it prevents spurious
     * javadoc warnings with JDK 18 and later.
     * </p>
     * @since 3.0
     */
    public UTF8Control() { // NOPMD - unnecessary constructor added intentionally to make javadoc happy
        // nothing to do
    }

    /** {@inheritDoc} */
    @Override
    public ResourceBundle newBundle(final String baseName, final Locale locale, final String format,
                                    final ClassLoader loader, final boolean reload)
        throws IllegalAccessException, InstantiationException, IOException {
        // The below is a copy of the default implementation.
        final String bundleName = toBundleName(baseName, locale);
        final String resourceName = toResourceName(bundleName, "utf8");
        ResourceBundle bundle = null;
        InputStream stream = null;
        if (reload) {
            final URL url = loader.getResource(resourceName);
            if (url != null) {
                final URLConnection connection = url.openConnection();
                if (connection != null) {
                    connection.setUseCaches(false);
                    stream = connection.getInputStream();
                }
            }
        } else {
            stream = loader.getResourceAsStream(resourceName);
        }
        if (stream != null) {
            try { // NOPMD
                // Only this line is changed to make it to read properties files as UTF-8.
                bundle = new PropertyResourceBundle(new InputStreamReader(stream, "UTF-8"));
            } finally {
                stream.close();
            }
        }
        return bundle;
    }

}