org.sonar.server.util.ClassLoaderUtils.java Source code

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Here is the source code for org.sonar.server.util.ClassLoaderUtils.java

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/*
 * SonarQube
 * Copyright (C) 2009-2017 SonarSource SA
 * mailto:info AT sonarsource DOT com
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
package org.sonar.server.util;

import com.google.common.base.Throwables;
import com.google.common.collect.Lists;
import java.net.URL;
import java.net.URLDecoder;
import java.util.Collection;
import java.util.Enumeration;
import java.util.function.Predicate;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;
import javax.annotation.Nullable;
import org.apache.commons.lang.CharEncoding;
import org.apache.commons.lang.StringUtils;
import org.sonar.api.utils.log.Loggers;

public class ClassLoaderUtils {

    private ClassLoaderUtils() {
        // only static methods
    }

    /**
     * Finds files within a given directory and its subdirectories
     *
     * @param classLoader
     * @param rootPath    the root directory, for example org/sonar/sqale
     * @return a list of relative paths, for example {"org/sonar/sqale/foo/bar.txt}. Never null.
     */
    public static Collection<String> listFiles(ClassLoader classLoader, String rootPath) {
        return listResources(classLoader, rootPath, path -> !StringUtils.endsWith(path, "/"));
    }

    /**
     * Finds directories and files within a given directory and its subdirectories.
     *
     * @param classLoader
     * @param rootPath    the root directory, for example org/sonar/sqale, or a file in this root directory, for example org/sonar/sqale/index.txt
     * @param predicate
     * @return a list of relative paths, for example {"org/sonar/sqale", "org/sonar/sqale/foo", "org/sonar/sqale/foo/bar.txt}. Never null.
     */
    public static Collection<String> listResources(ClassLoader classLoader, String rootPath,
            Predicate<String> predicate) {
        String jarPath = null;
        JarFile jar = null;
        try {
            Collection<String> paths = Lists.newArrayList();
            URL root = classLoader.getResource(rootPath);
            if (root != null) {
                checkJarFile(root);

                // Path of the root directory
                // Examples :
                // org/sonar/sqale/index.txt -> rootDirectory is org/sonar/sqale
                // org/sonar/sqale/ -> rootDirectory is org/sonar/sqale
                // org/sonar/sqale -> rootDirectory is org/sonar/sqale
                String rootDirectory = rootPath;
                if (StringUtils.substringAfterLast(rootPath, "/").indexOf('.') >= 0) {
                    rootDirectory = StringUtils.substringBeforeLast(rootPath, "/");
                }
                // strip out only the JAR file
                jarPath = root.getPath().substring(5, root.getPath().indexOf('!'));
                jar = new JarFile(URLDecoder.decode(jarPath, CharEncoding.UTF_8));
                Enumeration<JarEntry> entries = jar.entries();
                while (entries.hasMoreElements()) {
                    String name = entries.nextElement().getName();
                    if (name.startsWith(rootDirectory) && predicate.test(name)) {
                        paths.add(name);
                    }
                }
            }
            return paths;
        } catch (Exception e) {
            throw Throwables.propagate(e);
        } finally {
            closeJar(jar, jarPath);
        }
    }

    private static void closeJar(@Nullable JarFile jar, String jarPath) {
        if (jar != null) {
            try {
                jar.close();
            } catch (Exception e) {
                Loggers.get(ClassLoaderUtils.class).error("Fail to close JAR file: " + jarPath, e);
            }
        }
    }

    private static void checkJarFile(URL root) {
        if (!"jar".equals(root.getProtocol())) {
            throw new IllegalStateException("Unsupported protocol: " + root.getProtocol());
        }
    }
}