/*

  * This file is part of dependency-check-core.

  *

  * Dependency-check-core is free software: you can redistribute it and/or modify it

  * under the terms of the GNU General Public License as published by the Free

  * Software Foundation, either version 3 of the License, or (at your option) any

  * later version.

  *

  * Dependency-check-core 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 General Public License for more

  * details.

  *

  * You should have received a copy of the GNU General Public License along with

  * dependency-check-core. If not, see http://www.gnu.org/licenses/.

  *

  * Copyright (c) 2014 Jeremy Long. All Rights Reserved.

  */

 package org.owasp.dependencycheck.data.nvdcve;

 import java.io.File;

 import java.net.MalformedURLException;

 import java.net.URL;

 import java.net.URLClassLoader;

 import java.security.AccessController;

 import java.security.PrivilegedAction;

 import java.sql.Driver;

 import java.sql.DriverManager;

 import java.sql.SQLException;

 import java.util.ArrayList;

 import java.util.logging.Level;

 import java.util.logging.Logger;

 /**

  * DriverLoader is a utility class that is used to load database drivers.

  *

  * @author Jeremy Long <jeremy.long@owasp.org>

  */

 public final class DriverLoader {

     /**

      * Private constructor for a utility class.

      */

     private DriverLoader() {

     }

     /**

      * Loads the specified class using the system class loader and registers the driver with the driver manager.

      *

      * @param className the fully qualified name of the desired class

      * @throws DriverLoadException thrown if the driver cannot be loaded

      */

     public static void load(String className) throws DriverLoadException {

         final ClassLoader loader = ClassLoader.getSystemClassLoader();

         load(className, loader);

     }

     /**

      * Loads the specified class by registering the supplied paths to the class loader and then registers the driver

      * with the driver manager. The pathToDriver argument is added to the class loader so that an external driver can be

      * loaded. Note, the pathTodriver can contain a semi-colon separated list of paths so any dependencies can be added

      * as needed. If a path in the pathToDriver argument is a directory all files in the directory are added to the

      * class path.

      *

      * @param className the fully qualified name of the desired class

      * @param pathToDriver the path to the JAR file containing the driver; note, this can be a semi-colon separated list

      * of paths

      * @throws DriverLoadException thrown if the driver cannot be loaded

      */

     public static void load(String className, String pathToDriver) throws DriverLoadException {

         final URLClassLoader parent = (URLClassLoader) ClassLoader.getSystemClassLoader();

         final ArrayList<URL> urls = new ArrayList<URL>();

         final String[] paths = pathToDriver.split(File.pathSeparator);

         for (String path : paths) {

             final File file = new File(path);

             if (file.isDirectory()) {

                 final File[] files = file.listFiles();

                 for (File f : files) {

                     try {

                         urls.add(f.toURI().toURL());

                     } catch (MalformedURLException ex) {

                         final String msg = String.format("Unable to load database driver '%s'; invalid path provided '%s'",

                                 className, f.getAbsoluteFile());

                         Logger.getLogger(DriverLoader.class.getName()).log(Level.FINE, msg, ex);

                         throw new DriverLoadException(msg, ex);

                     }

                 }

             } else if (file.exists()) {

                 try {

                     urls.add(file.toURI().toURL());

                 } catch (MalformedURLException ex) {

                     final String msg = String.format("Unable to load database driver '%s'; invalid path provided '%s'",

                             className, file.getAbsoluteFile());

                     Logger.getLogger(DriverLoader.class.getName()).log(Level.FINE, msg, ex);

                     throw new DriverLoadException(msg, ex);

                 }

             }

         }

         final URLClassLoader loader = AccessController.doPrivileged(new PrivilegedAction<URLClassLoader>() {

             @Override

             public URLClassLoader run() {

                 return new URLClassLoader(urls.toArray(new URL[urls.size()]), parent);

             }

         });

         load(className, loader);

     }

     /**

      * Loads the specified class using the supplied class loader and registers the driver with the driver manager.

      *

      * @param className the fully qualified name of the desired class

      * @param loader the class loader to use when loading the driver

      * @throws DriverLoadException thrown if the driver cannot be loaded

      */

     private static void load(String className, ClassLoader loader) throws DriverLoadException {

         try {

             final Class c = loader.loadClass(className);

             final Driver driver = (Driver) c.newInstance();

             //using the DriverShim to get around the fact that the DriverManager won't register a driver not in the base class path

             DriverManager.registerDriver(new DriverShim(driver));

         } catch (ClassNotFoundException ex) {

             final String msg = String.format("Unable to load database driver '%s'", className);

             Logger.getLogger(DriverLoader.class.getName()).log(Level.FINE, msg, ex);

             throw new DriverLoadException(msg, ex);

         } catch (InstantiationException ex) {

             final String msg = String.format("Unable to load database driver '%s'", className);

             Logger.getLogger(DriverLoader.class.getName()).log(Level.FINE, msg, ex);

             throw new DriverLoadException(msg, ex);

         } catch (IllegalAccessException ex) {

             final String msg = String.format("Unable to load database driver '%s'", className);

             Logger.getLogger(DriverLoader.class.getName()).log(Level.FINE, msg, ex);

             throw new DriverLoadException(msg, ex);

         } catch (SQLException ex) {

             final String msg = String.format("Unable to load database driver '%s'", className);

             Logger.getLogger(DriverLoader.class.getName()).log(Level.FINE, msg, ex);

             throw new DriverLoadException(msg, ex);

         }

     }

 }