de.smartics.maven.plugin.jboss.modules.parser.ModulesXmlLocator.java Source code

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Here is the source code for de.smartics.maven.plugin.jboss.modules.parser.ModulesXmlLocator.java

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/*
 * Copyright 2013-2015 smartics, Kronseder & Reiner GmbH
 *
 * 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 de.smartics.maven.plugin.jboss.modules.parser;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;

import org.apache.commons.io.FileUtils;
import org.apache.commons.io.IOUtils;
import org.apache.commons.lang.StringUtils;
import org.jdom2.JDOMException;

import de.smartics.maven.plugin.jboss.modules.descriptor.ModulesDescriptor;
import de.smartics.util.lang.classpath.ClassPathContext;
import de.smartics.util.lang.classpath.ClassPathListing;
import de.smartics.util.lang.classpath.JarAndFileClassPathListing;

/**
 * Discovers all module descriptors on the class path.
 */
public final class ModulesXmlLocator {
    // ********************************* Fields *********************************

    // --- constants ------------------------------------------------------------

    // --- members --------------------------------------------------------------

    /**
     * The parser of external modules XML documents.
     */
    private final ModulesXmlParser parser = new ModulesXmlParser();

    /**
     * The name of the slot to map modules without slot to.
     */
    private final String targetSlot;

    // ****************************** Initializer *******************************

    // ****************************** Constructors ******************************

    /**
     * Default constructor.
     *
     * @param targetSlot the name of the slot to map modules without slot to.
     */
    public ModulesXmlLocator(final String targetSlot) {
        this.targetSlot = StringUtils.isNotBlank(targetSlot) && !"main".equals(targetSlot) ? targetSlot : null;
    }

    // ****************************** Inner Classes *****************************

    // ********************************* Methods ********************************

    // --- init -----------------------------------------------------------------

    // --- get&set --------------------------------------------------------------

    // --- business -------------------------------------------------------------

    /**
     * Discovers all module descriptors on the class path.
     *
     * @param classLoader the class loader whose class path is searched.
     * @param rootDirectories additional root directories to check first.
     * @return the discovered module descriptors.
     * @throws IOException if resources cannot be loaded from the class path.
     */
    public List<ModulesDescriptor> discover(final ClassLoader classLoader, final List<File> rootDirectories)
            throws IOException {
        final List<ModulesDescriptor> modules = new ArrayList<ModulesDescriptor>();

        for (final File rootDirectory : rootDirectories) {
            loadModules(modules, rootDirectory);
        }

        final ClassPathListing listing = new JarAndFileClassPathListing();
        final ClassPathContext context = new ClassPathContext(classLoader, null);
        final Enumeration<URL> urls = classLoader.getResources("jboss-modules");
        while (urls.hasMoreElements()) {
            final List<String> fileList = listing.list(context, "jboss-modules");
            final URL url = urls.nextElement();
            loadModules(modules, url, fileList);
        }

        if (targetSlot != null) {
            for (final ModulesDescriptor module : modules) {
                module.applyDefaultSlot(targetSlot);
            }
        }

        return modules;
    }

    private void loadModules(final List<ModulesDescriptor> modules, final URL url, final List<String> fileList)
            throws IOException {
        for (final String file : fileList) {
            if (!file.endsWith(".xml")) {
                continue;
            }

            final URL fileUrl = new URL(url.toExternalForm() + '/' + file);
            final InputStream input = new BufferedInputStream(fileUrl.openStream());
            final String urlString = fileUrl.toExternalForm();
            try {
                final ModulesDescriptor descriptor = parser.parse(urlString, input);
                modules.add(descriptor);
            } catch (final JDOMException e) {
                throw new IOException("Cannot parse XML file: " + urlString, e);
            } finally {
                IOUtils.closeQuietly(input);
            }
        }
    }

    private void loadModules(final List<ModulesDescriptor> modules, final File rootDirectory) throws IOException {
        final File[] fileList = rootDirectory.listFiles();
        for (final File file : fileList) {
            if (!file.getName().endsWith(".xml")) {
                continue;
            }

            final InputStream input = new BufferedInputStream(FileUtils.openInputStream(file));
            final String fileId = file.getAbsolutePath();
            try {
                final ModulesDescriptor descriptor = parser.parse(fileId, input);
                modules.add(descriptor);
            } catch (final JDOMException e) {
                throw new IOException("Cannot parse XML file: " + fileId, e);
            } finally {
                IOUtils.closeQuietly(input);
            }
        }
    }

    // --- object basics --------------------------------------------------------

}