org.wicketstuff.extjs.ExtContributionFactory.java Source code

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Here is the source code for org.wicketstuff.extjs.ExtContributionFactory.java

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/*
 *  Copyright 2008 Wicket-Ext
 *
 * Licensed 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.wicketstuff.extjs;

import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.Enumeration;
import java.util.Properties;

import org.apache.wicket.util.lang.Objects;
import org.apache.wicket.util.string.Strings;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Default Bundle contribution factory. It will load the bundle contribution specified by a <code>ext.properties</code>
 * file found on the application classpath
 *
 * @author Paolo Di Tommaso
 *
 */
public class ExtContributionFactory {

    private static final Logger log = LoggerFactory.getLogger(ExtContributionFactory.class);

    /**
     * Default load strategy
     */
    public ExtContribution load() {
        Enumeration<URL> resources;
        try {
            resources = Thread.currentThread().getContextClassLoader().getResources("META-INF/ext.properties");

            while (resources.hasMoreElements()) {
                InputStream in = null;
                try {
                    final URL url = resources.nextElement();
                    final Properties properties = new Properties();
                    in = url.openStream();
                    properties.load(in);
                    String bundle = properties.getProperty("bundle");
                    if (!Strings.isEmpty(bundle)) {
                        log.info("Loading Wicket-Ext bundle class --> {}", bundle);
                        return (ExtContribution) Objects.newInstance(bundle);
                    }

                } finally {
                    if (in != null) {
                        in.close();
                    }
                }
            }

        } catch (IOException e) {
            log.error("Unable to load 'ext.properties'", e);
        }

        throw new RuntimeException(
                "Unable to initialize Wicket-Ext. You must provide the Ext resources bundle factory in the 'ext.properties' configuration file ");

    }

}