com.dattack.naming.standalone.StandaloneContextFactory.java Source code

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Here is the source code for com.dattack.naming.standalone.StandaloneContextFactory.java

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/*
 * Copyright (c) 2016, The Dattack team (http://www.dattack.com)
 * 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 com.dattack.naming.standalone;

import java.io.File;
import java.io.IOException;
import java.util.Collection;
import java.util.Hashtable;
import java.util.Map;
import java.util.Map.Entry;

import javax.naming.ConfigurationException;
import javax.naming.Context;
import javax.naming.NamingException;
import javax.naming.spi.InitialContextFactory;

import org.apache.commons.configuration.BaseConfiguration;
import org.apache.commons.configuration.CompositeConfiguration;
import org.apache.commons.configuration.EnvironmentConfiguration;
import org.apache.commons.configuration.PropertyConverter;
import org.apache.commons.configuration.SystemConfiguration;
import org.apache.commons.lang.ObjectUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.dattack.jtoolbox.io.FilesystemUtils;
import com.dattack.naming.loader.NamingLoader;

/**
 * Initial Context Factory for {@link StandaloneContext}.
 *
 * @author cvarela
 * @since 0.1
 */
public final class StandaloneContextFactory implements InitialContextFactory {

    private static final Logger LOGGER = LoggerFactory.getLogger(StandaloneContextFactory.class);

    private static final String CLASSPATH_DIRECTORY_PROPERTY = StandaloneContextFactory.class.getName()
            + ".classpath.directory";

    private static final String RESOURCES_DIRECTORY_PROPERTY = StandaloneContextFactory.class.getName()
            + ".resources.directory";

    private static volatile Context context;

    private static Context createInitialContext(final File dir, final Map<?, ?> environment,
            final CompositeConfiguration configuration) throws NamingException {

        LOGGER.debug("Scanning directory '{}' for JNDI resources.", dir);
        try {
            final StandaloneContext ctx = new StandaloneContext(environment);
            final NamingLoader loader = new NamingLoader();
            final Collection<File> extraClasspath = FilesystemUtils
                    .locateFiles(configuration.getList(CLASSPATH_DIRECTORY_PROPERTY));
            loader.loadDirectory(dir, ctx, extraClasspath);

            LOGGER.debug("JNDI context is ready");

            return ctx;
        } catch (final IOException e) {
            throw (NamingException) new NamingException(e.getMessage()).initCause(e);
        }
    }

    private static CompositeConfiguration getConfiguration(final Map<?, ?> environment) {

        final BaseConfiguration baseConf = new BaseConfiguration();
        for (final Entry<?, ?> entry : environment.entrySet()) {
            baseConf.setProperty(ObjectUtils.toString(entry.getKey()), entry.getValue());
        }

        final CompositeConfiguration configuration = new CompositeConfiguration();
        configuration.addConfiguration(new SystemConfiguration());
        configuration.addConfiguration(new EnvironmentConfiguration());
        configuration.addConfiguration(baseConf);
        return configuration;
    }

    @Override
    public Context getInitialContext(final Hashtable<?, ?> environment) throws NamingException {

        if (context == null) {
            synchronized (StandaloneContextFactory.class) {
                if (context == null) {
                    context = loadInitialContext(environment);
                }
            }
        }
        return context;
    }

    private static String getResourcesDirectory(final CompositeConfiguration configuration)
            throws ConfigurationException {

        final Object configDir = PropertyConverter
                .interpolate(configuration.getProperty(RESOURCES_DIRECTORY_PROPERTY), configuration);

        if (configDir == null) {
            throw new ConfigurationException(
                    String.format("JNDI configuration error: missing property '%s'", RESOURCES_DIRECTORY_PROPERTY));
        }

        return configDir.toString();
    }

    private static Context loadInitialContext(final Hashtable<?, ?> environment) // NOPMD by cvarela
            throws NamingException {

        LOGGER.debug("loadInitialContext: {}", environment);
        final CompositeConfiguration configuration = getConfiguration(environment);

        final Object configDir = getResourcesDirectory(configuration);

        final File dir = FilesystemUtils.locateFile(ObjectUtils.toString(configDir));

        if ((dir != null) && dir.exists()) {
            return createInitialContext(dir, environment, configuration);
        }

        throw new ConfigurationException(
                String.format("JNDI configuration error: directory not exists '%s'", configDir));
    }
}