package de.juplo.plugins.hibernate4;
   
   /*
    * Copyright 2001-2005 The Apache Software Foundation.
    *
    * 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.
   */
  
  import com.pyx4j.log4j.MavenLogAppender;
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.FileNotFoundException;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.ObjectInputStream;
  import java.io.ObjectOutputStream;
  import java.math.BigInteger;
  import java.net.URL;
  import java.net.URLClassLoader;
  import java.security.MessageDigest;
  import java.security.NoSuchAlgorithmException;
  import java.sql.Driver;
  import java.sql.DriverPropertyInfo;
  import java.sql.SQLException;
  import java.sql.SQLFeatureNotSupportedException;
  import java.util.Collections;
  import java.util.Comparator;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.LinkedHashSet;
  import java.util.LinkedList;
  import java.util.List;
  import java.util.Map;
  import java.util.Map.Entry;
  import java.util.Properties;
  import java.util.Set;
  import java.util.TreeSet;
  import java.util.logging.Logger;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  import javax.persistence.Embeddable;
  import javax.persistence.Entity;
  import javax.persistence.MappedSuperclass;
  import javax.persistence.spi.PersistenceUnitTransactionType;
  import org.apache.maven.artifact.Artifact;
  import org.apache.maven.model.Resource;
  import org.apache.maven.plugin.AbstractMojo;
  import org.apache.maven.plugin.MojoExecutionException;
  import org.apache.maven.plugin.MojoFailureException;
  import org.apache.maven.project.MavenProject;
  import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
  import org.hibernate.boot.registry.classloading.spi.ClassLoaderService;
  import org.hibernate.boot.registry.classloading.spi.ClassLoadingException;
  import org.hibernate.boot.registry.internal.StandardServiceRegistryImpl;
  import org.hibernate.cfg.Environment;
  import org.hibernate.cfg.NamingStrategy;
  import org.hibernate.envers.configuration.spi.AuditConfiguration;
  import org.hibernate.internal.util.config.ConfigurationHelper;
  import org.hibernate.jpa.boot.internal.ParsedPersistenceXmlDescriptor;
  import org.hibernate.jpa.boot.internal.PersistenceXmlParser;
  import org.hibernate.jpa.boot.spi.ProviderChecker;
  import org.hibernate.tool.hbm2ddl.SchemaExport;
  import org.hibernate.tool.hbm2ddl.SchemaExport.Type;
  import org.hibernate.tool.hbm2ddl.Target;
  import org.scannotation.AnnotationDB;
  
  
  /**
   * Goal which extracts the hibernate-mapping-configuration and
   * exports an according SQL-database-schema.
   *
   * @goal export
   * @phase process-classes
   * @threadSafe
   * @requiresDependencyResolution runtime
   */
  public class Hbm2DdlMojo extends AbstractMojo
  {
    public final static String EXPORT_SKIPPED_PROPERTY = "hibernate.export.skipped";
  
    public final static String DRIVER_CLASS = "hibernate.connection.driver_class";
    public final static String URL = "hibernate.connection.url";
    public final static String USERNAME = "hibernate.connection.username";
    public final static String PASSWORD = "hibernate.connection.password";
    public final static String DIALECT = "hibernate.dialect";
    public final static String NAMING_STRATEGY="hibernate.ejb.naming_strategy";
    public final static String ENVERS = "hibernate.export.envers";
  
   public final static String JPA_DRIVER = "javax.persistence.jdbc.driver";
   public final static String JPA_URL = "javax.persistence.jdbc.url";
   public final static String JPA_USERNAME = "javax.persistence.jdbc.user";
   public final static String JPA_PASSWORD = "javax.persistence.jdbc.password";
 
   public final static String MD5S = "hibernate4-generatedschema.md5s";
 
   private final static Pattern split = Pattern.compile("[^,\\s]+");
 
 
   /**
    * The maven project.
    * <p>
    * Only needed internally.
    *
    * @parameter property="project"
    * @required
    * @readonly
    */
   private MavenProject project;
 
   /**
    * Build-directory.
    * <p>
    * Only needed internally.
    *
    * @parameter property="project.build.directory"
    * @required
    * @readonly
    */
   private String buildDirectory;
 
   /**
    * Classes-Directory to scan.
    * <p>
    * This parameter defaults to the maven build-output-directory for classes.
    * Additionally, all dependencies are scanned for annotated classes.
    *
    * @parameter property="project.build.outputDirectory"
    * @since 1.0
    */
   private String outputDirectory;
 
   /**
    * Whether to scan test-classes too, or not.
    * <p>
    * If this parameter is set to <code>true</code> the test-classes of the
    * artifact will be scanned for hibernate-annotated classes additionally.
    *
    * @parameter property="hibernate.export.scan_testclasses" default-value="false"
    * @since 1.0.1
    */
   private boolean scanTestClasses;
 
   /**
    * Dependency-Scopes, that should be scanned for annotated classes.
    * <p>
    * By default, only dependencies in the scope <code>compile</code> are
    * scanned for annotated classes. Multiple scopes can be seperated by
    * white space or commas.
    * <p>
    * If you do not want any dependencies to be scanned for annotated
    * classes, set this parameter to <code>none</code>.
    * <p>
    * The plugin does not scan for annotated classes in transitive
    * dependencies. If some of your annotated classes are hidden in a
    * transitive dependency, you can simply add that dependency explicitly.
    *
    * @parameter property="hibernate.export.scan_dependencies" default-value="compile"
    * @since 1.0.3
    */
   private String scanDependencies;
 
   /**
    * Test-Classes-Directory to scan.
    * <p>
    * This parameter defaults to the maven build-output-directory for
    * test-classes.
    * <p>
    * This parameter is only used, when <code>scanTestClasses</code> is set
    * to <code>true</code>!
    *
    * @parameter property="project.build.testOutputDirectory"
    * @since 1.0.2
    */
   private String testOutputDirectory;
 
   /**
    * Skip execution
    * <p>
    * If set to <code>true</code>, the execution is skipped.
    * <p>
    * A skipped execution is signaled via the maven-property
    * <code>${hibernate.export.skipped}</code>.
    * <p>
    * The execution is skipped automatically, if no modified or newly added
    * annotated classes are found and the dialect was not changed.
    *
    * @parameter property="hibernate.skip" default-value="${maven.test.skip}"
    * @since 1.0
    */
   private boolean skip;
 
   /**
    * Force execution
    * <p>
    * Force execution, even if no modified or newly added annotated classes
    * where found and the dialect was not changed.
    * <p>
    * <code>skip</code> takes precedence over <code>force</code>.
    *
    * @parameter property="hibernate.export.force" default-value="false"
    * @since 1.0
    */
   private boolean force;
 
   /**
    * SQL-Driver name.
    *
    * @parameter property="hibernate.connection.driver_class"
    * @since 1.0
    */
   private String driverClassName;
 
   /**
    * Database URL.
    *
    * @parameter property="hibernate.connection.url"
    * @since 1.0
    */
   private String url;
 
   /**
    * Database username
    *
    * @parameter property="hibernate.connection.username"
    * @since 1.0
    */
   private String username;
 
   /**
    * Database password
    *
    * @parameter property="hibernate.connection.password"
    * @since 1.0
    */
   private String password;
 
   /**
    * Hibernate dialect.
    *
    * @parameter property="hibernate.dialect"
    * @since 1.0
    */
   private String hibernateDialect;
 
   /**
    * Hibernate Naming Strategy
    *
    * @parameter property="hibernate.ejb.naming_strategy"
    * @since 1.0.2
    */
   private String hibernateNamingStrategy;
 
   /**
    * Path to Hibernate properties file.
    * If this parameter is not set the plugin will try to load the configuration
    * from a file <code>hibernate.properties</code> on the classpath. The
    * test-classpath takes precedence.
    *
    * @parameter
    * @since 1.0
    */
   private String hibernateProperties;
 
   /**
    * Path to Hibernate configuration file (.cfg.xml).
    * Settings in this file will overwrite settings in the properties file.
    * If this parameter is not set the plugin will try to load the configuration
    * from a file <code>hibernate.cfg.xml</code> on the classpath. The
    * test-classpath takes precedence.
    *
    * @parameter
    * @since 1.1.0
    */
   private String hibernateConfig;
 
   /**
    * Name of the persistence-unit.
    * If there is only one persistence-unit available, that unit will be used
    * automatically.
    * Settings in this file will overwrite settings in the properties or the
    * configuration file.
    *
    * @parameter
    * @since 1.1.0
    */
   private String persistenceUnit;
 
   /**
    * List of Hibernate-Mapping-Files (XML).
    * Multiple files can be separated with white-spaces and/or commas.
    *
    * @parameter property="hibernate.mapping"
    * @since 1.0.2
    */
   private String hibernateMapping;
 
   /**
    * Target of execution:
    * <ul>
    *   <li><strong>NONE</strong> only export schema to SQL-script (forces execution, signals skip)</li>
    *   <li><strong>EXPORT</strong> create database (<strong>DEFAULT!</strong>). forces execution, signals skip)</li>
    *   <li><strong>SCRIPT</strong> export schema to SQL-script and print it to STDOUT</li>
    *   <li><strong>BOTH</strong></li>
    * </ul>
    *
    * A database connection is only needed for EXPORT and BOTH, but a
    * Hibernate-Dialect must always be chosen.
    *
    * @parameter property="hibernate.export.target" default-value="EXPORT"
    * @since 1.0
    */
   private String target;
 
   /**
    * Type of execution.
    * <ul>
    *   <li><strong>NONE</strong> do nothing - just validate the configuration</li>
    *   <li><strong>CREATE</strong> create database-schema</li>
    *   <li><strong>DROP</strong> drop database-schema</li>
    *   <li><strong>BOTH</strong> (<strong>DEFAULT!</strong>)</li>
    * </ul>
    *
    * If NONE is choosen, no databaseconnection is needed.
    *
    * @parameter property="hibernate.export.type" default-value="BOTH"
    * @since 1.0
    */
   private String type;
 
   /**
    * Output file.
    *
    * @parameter property="hibernate.export.schema.filename" default-value="${project.build.directory}/schema.sql"
    * @since 1.0
    */
   private String outputFile;
 
   /**
    * Delimiter in output-file.
    *
    * @parameter property="hibernate.export.schema.delimiter" default-value=";"
    * @since 1.0
    */
   private String delimiter;
 
   /**
    * Format output-file.
    *
    * @parameter property="hibernate.export.schema.format" default-value="true"
    * @since 1.0
    */
   private boolean format;
 
   /**
    * Generate envers schema for auditing tables.
    *
    * @parameter property="hibernate.export.envers" default-value="true"
    * @since 1.0.3
    */
   private boolean envers;
 
 
   @Override
   public void execute()
     throws
       MojoFailureException,
       MojoExecutionException
   {
     if (skip)
     {
       getLog().info("Execution of hibernate4-maven-plugin:export was skipped!");
       project.getProperties().setProperty(EXPORT_SKIPPED_PROPERTY, "true");
       return;
     }
 
     Map<String,String> md5s;
     boolean modified = false;
     File saved = new File(buildDirectory + File.separator + MD5S);
 
     if (saved.isFile() && saved.length() > 0)
     {
       try
       {
         FileInputStream fis = new FileInputStream(saved);
         ObjectInputStream ois = new ObjectInputStream(fis);
         md5s = (HashMap<String,String>)ois.readObject();
         ois.close();
       }
       catch (Exception e)
       {
         md5s = new HashMap<String,String>();
         getLog().warn("Cannot read timestamps from saved: " + e);
       }
     }
     else
     {
       md5s = new HashMap<String,String>();
       try
       {
         saved.createNewFile();
       }
       catch (IOException e)
       {
         getLog().debug("Cannot create file \"" + saved.getPath() + "\" for timestamps: " + e);
       }
     }
 
     URLClassLoader classLoader = null;
     try
     {
       getLog().debug("Creating ClassLoader for project-dependencies...");
       List<String> classpathFiles = project.getCompileClasspathElements();
       if (scanTestClasses)
         classpathFiles.addAll(project.getTestClasspathElements());
       List<URL> urls = new LinkedList<URL>();
       File file;
       file = new File(testOutputDirectory);
       if (!file.exists())
       {
         getLog().info("creating test-output-directory: " + testOutputDirectory);
         file.mkdirs();
       }
       urls.add(file.toURI().toURL());
       file = new File(outputDirectory);
       if (!file.exists())
       {
         getLog().info("creating output-directory: " + outputDirectory);
         file.mkdirs();
       }
       urls.add(file.toURI().toURL());
       for (String pathElement : classpathFiles)
       {
         getLog().debug("Dependency: " + pathElement);
         urls.add(new File(pathElement).toURI().toURL());
       }
       classLoader =
           new URLClassLoader(
               urls.toArray(new URL[urls.size()]),
               getClass().getClassLoader()
               );
     }
     catch (Exception e)
     {
       getLog().error("Error while creating ClassLoader!", e);
       throw new MojoExecutionException(e.getMessage());
     }
 
     Set<Class<?>> classes =
         new TreeSet<Class<?>>(
             new Comparator<Class<?>>() {
               @Override
               public int compare(Class<?> a, Class<?> b)
               {
                 return a.getName().compareTo(b.getName());
               }
             }
           );
 
     try
     {
       AnnotationDB db = new AnnotationDB();
       File dir = new File(outputDirectory);
       if (dir.exists())
       {
         getLog().info("Scanning directory " + outputDirectory + " for annotated classes...");
         URL dirUrl = dir.toURI().toURL();
         db.scanArchives(dirUrl);
       }
       if (scanTestClasses)
       {
         dir = new File(testOutputDirectory);
         if (dir.exists())
         {
           getLog().info("Scanning directory " + testOutputDirectory + " for annotated classes...");
           URL dirUrl = dir.toURI().toURL();
           db.scanArchives(dirUrl);
         }
       }
       if (scanDependencies != null)
       {
         Matcher matcher = split.matcher(scanDependencies);
         while (matcher.find())
         {
           getLog().info("Scanning dependencies for scope " + matcher.group());
           for (Artifact artifact : project.getDependencyArtifacts())
           {
             if (!artifact.getScope().equalsIgnoreCase(matcher.group()))
               continue;
             if (artifact.getFile() == null)
             {
               getLog().warn(
                   "Cannot scan dependency " +
                   artifact.getId() +
                   ": no JAR-file available!"
                   );
               continue;
             }
             getLog().info(
                 "Scanning dependency " +
                 artifact.getId() +
                 " for annotated classes..."
                 );
             db.scanArchives(artifact.getFile().toURI().toURL());
           }
         }
       }
 
       Set<String> classNames = new HashSet<String>();
       if (db.getAnnotationIndex().containsKey(Entity.class.getName()))
         classNames.addAll(db.getAnnotationIndex().get(Entity.class.getName()));
       if (db.getAnnotationIndex().containsKey(MappedSuperclass.class.getName()))
         classNames.addAll(db.getAnnotationIndex().get(MappedSuperclass.class.getName()));
       if (db.getAnnotationIndex().containsKey(Embeddable.class.getName()))
         classNames.addAll(db.getAnnotationIndex().get(Embeddable.class.getName()));
 
       MessageDigest digest = java.security.MessageDigest.getInstance("MD5");
       for (String name : classNames)
       {
         Class<?> annotatedClass = classLoader.loadClass(name);
         classes.add(annotatedClass);
         String resourceName = annotatedClass.getName();
         resourceName = resourceName.substring(resourceName.lastIndexOf(".") + 1, resourceName.length()) + ".class";
         InputStream is =
             annotatedClass
                 .getResourceAsStream(resourceName);
         byte[] buffer = new byte[1024*4]; // copy data in 4MB-chunks
         int i;
         while((i = is.read(buffer)) > -1)
           digest.update(buffer, 0, i);
         is.close();
         byte[] bytes = digest.digest();
         BigInteger bi = new BigInteger(1, bytes);
         String newMd5 = String.format("%0" + (bytes.length << 1) + "x", bi);
         String oldMd5 = !md5s.containsKey(name) ? "" : md5s.get(name);
         if (!newMd5.equals(oldMd5))
         {
           getLog().debug("Found new or modified annotated class: " + name);
           modified = true;
           md5s.put(name, newMd5);
         }
         else
         {
           getLog().debug(oldMd5 + " -> class unchanged: " + name);
         }
       }
     }
     catch (ClassNotFoundException e)
     {
       getLog().error("Error while adding annotated classes!", e);
       throw new MojoExecutionException(e.getMessage());
     }
     catch (Exception e)
     {
       getLog().error("Error while scanning!", e);
       throw new MojoFailureException(e.getMessage());
     }
 
 
     ValidationConfiguration config = new ValidationConfiguration();
     // Clear unused system-properties
     config.setProperties(new Properties());
 
 
     ClassLoader contextClassLoader = Thread.currentThread().getContextClassLoader();
     StandardServiceRegistryImpl registry = null;
     MavenLogAppender.startPluginLog(this);
 
     try
     {
       /**
        * Change class-loader of current thread, so that hibernate can
        * see all dependencies!
        */
       Thread.currentThread().setContextClassLoader(classLoader);
 
 
       /** Try to read configuration from properties-file */
       try
       {
         if (hibernateProperties == null)
         {
           URL url = classLoader.findResource("hibernate.properties");
           if (url == null)
           {
             getLog().info("No hibernate.properties on the classpath!");
           }
           else
           {
             getLog().info("Reading settings from hibernate.properties on the classpath.");
             Properties properties = new Properties();
             properties.load(url.openStream());
             config.setProperties(properties);
           }
         }
         else
         {
           File file = new File(hibernateProperties);
           if (file.exists())
           {
             getLog().info("Reading settings from file " + hibernateProperties + "...");
             Properties properties = new Properties();
             properties.load(new FileInputStream(file));
             config.setProperties(properties);
           }
           else
             getLog().info("No hibernate-properties-file found! (Checked path: " + hibernateProperties + ")");
         }
       }
       catch (IOException e)
       {
         getLog().error("Error while reading properties!", e);
         throw new MojoExecutionException(e.getMessage());
       }
 
       /** Try to read configuration from configuration-file */
       try
       {
         if (hibernateConfig == null)
         {
           URL url = classLoader.findResource("hibernate.cfg.xml");
           if (url == null)
           {
             getLog().info("No hibernate.cfg.xml on the classpath!");
           }
           else
           {
             getLog().info("Reading settings from hibernate.cfg.xml on the classpath.");
             config.configure(url);
           }
         }
         else
         {
           File file = new File(hibernateConfig);
           if (file.exists())
           {
             getLog().info("Reading configuration from file " + hibernateConfig + "...");
             config.configure(file);
           }
           else
             getLog().info("No hibernate-configuration-file found! (Checked path: " + hibernateConfig + ")");
         }
       }
       catch (Exception e)
       {
         getLog().error("Error while reading configuration!", e);
         throw new MojoExecutionException(e.getMessage());
       }
 
       ParsedPersistenceXmlDescriptor persistenceUnitDescriptor =
           getPersistenceUnitDescriptor(
               persistenceUnit,
               config.getProperties(),
               new MavenProjectClassLoaderService(classLoader)
               );
       if (persistenceUnitDescriptor != null)
         config.setProperties(persistenceUnitDescriptor.getProperties());
 
 
       /** Overwrite values from properties-file or set, if given */
 
       if (driverClassName != null)
       {
         if (config.getProperties().containsKey(DRIVER_CLASS))
           getLog().debug(
               "Overwriting property " +
               DRIVER_CLASS + "=" + config.getProperty(DRIVER_CLASS) +
               " with the value " + driverClassName
             );
         else
           getLog().debug("Using the value " + driverClassName);
         config.setProperty(DRIVER_CLASS, driverClassName);
       }
       if (config.getProperty(DRIVER_CLASS) == null)
       {
         String driver = config.getProperty(JPA_DRIVER);
         if (driver != null)
         {
           getLog().info(
               DRIVER_CLASS +
               " is not set. Borrow setting from " +
               JPA_DRIVER +
               ": " +
               driver);
           config.setProperty(DRIVER_CLASS, driver);
         }
       }
 
       if (url != null)
       {
         if (config.getProperties().containsKey(URL))
           getLog().debug(
               "Overwriting property " +
               URL + "=" + config.getProperty(URL) +
               " with the value " + url
             );
         else
           getLog().debug("Using the value " + url);
         config.setProperty(URL, url);
       }
       if (config.getProperty(URL) == null)
       {
         String url = config.getProperty(JPA_URL);
         if (url != null)
         {
           getLog().info(
               URL +
               " is not set. Borrow setting from " +
               JPA_URL +
               ": " +
               url);
           config.setProperty(URL, url);
         }
       }
 
       if (username != null)
       {
         if (config.getProperties().containsKey(USERNAME))
           getLog().debug(
               "Overwriting property " +
               USERNAME + "=" + config.getProperty(USERNAME) +
               " with the value " + username
             );
         else
           getLog().debug("Using the value " + username);
         config.setProperty(USERNAME, username);
       }
       if (config.getProperty(USERNAME) == null)
       {
         String username = config.getProperty(JPA_USERNAME);
         if (username != null)
         {
           getLog().info(
               USERNAME +
               " is not set. Borrow setting from " +
               JPA_USERNAME +
               ": " +
               username);
           config.setProperty(USERNAME, username);
         }
       }
 
       if (password != null)
       {
         if (config.getProperties().containsKey(PASSWORD))
           getLog().debug(
               "Overwriting property " +
               PASSWORD + "=" + config.getProperty(PASSWORD) +
               " with value " + password
             );
         else
           getLog().debug("Using value " + password + " for property " + PASSWORD);
         config.setProperty(PASSWORD, password);
       }
       if (config.getProperty(PASSWORD) == null)
       {
         String password = config.getProperty(JPA_PASSWORD);
         if (password != null)
         {
           getLog().info(
               PASSWORD +
               " is not set. Borrow setting from " +
               JPA_PASSWORD +
               ": " +
               password);
           config.setProperty(PASSWORD, password);
         }
       }
 
       if (hibernateDialect != null)
       {
         if (config.getProperties().containsKey(DIALECT))
           getLog().debug(
               "Overwriting property " +
               DIALECT + "=" + config.getProperty(DIALECT) +
               " with value " + hibernateDialect
             );
         else
           getLog().debug(
               "Using value " + hibernateDialect + " for property " + DIALECT
               );
         config.setProperty(DIALECT, hibernateDialect);
       }
 
       if ( hibernateNamingStrategy != null )
       {
         if ( config.getProperties().contains(NAMING_STRATEGY))
           getLog().debug(
               "Overwriting property " +
               NAMING_STRATEGY + "=" + config.getProperty(NAMING_STRATEGY) +
               " with value " + hibernateNamingStrategy
              );
         else
           getLog().debug(
               "Using value " + hibernateNamingStrategy + " for property " +
               NAMING_STRATEGY
               );
         config.setProperty(NAMING_STRATEGY, hibernateNamingStrategy);
       }
 
       /** The generated SQL varies with the dialect! */
       if (md5s.containsKey(DIALECT))
       {
         String dialect = config.getProperty(DIALECT);
         if (md5s.get(DIALECT).equals(dialect))
           getLog().debug("SQL-dialect unchanged.");
         else
         {
           modified = true;
           if (dialect == null)
           {
             getLog().debug("SQL-dialect was unset.");
             md5s.remove(DIALECT);
           }
           else
           {
             getLog().debug("SQL-dialect changed: " + dialect);
             md5s.put(DIALECT, dialect);
           }
         }
       }
       else
       {
         String dialect = config.getProperty(DIALECT);
         if (dialect != null)
         {
           modified = true;
           md5s.put(DIALECT, config.getProperty(DIALECT));
         }
       }
 
       /** The generated SQL varies with the envers-configuration */
       if (md5s.get(ENVERS) != null)
       {
         if (md5s.get(ENVERS).equals(Boolean.toString(envers)))
           getLog().debug("Envers-Configuration unchanged. Enabled: " + envers);
         else
         {
           getLog().debug("Envers-Configuration changed. Enabled: " + envers);
           modified = true;
           md5s.put(ENVERS, Boolean.toString(envers));
         }
       }
       else
       {
         modified = true;
         md5s.put(ENVERS, Boolean.toString(envers));
       }
 
       if (config.getProperties().isEmpty())
       {
         getLog().error("No properties set!");
         throw new MojoFailureException("Hibernate configuration is missing!");
       }
 
       getLog().info("Gathered hibernate-configuration (turn on debugging for details):");
       for (Entry<Object,Object> entry : config.getProperties().entrySet())
         getLog().info("  " + entry.getKey() + " = " + entry.getValue());
 
 
       getLog().debug("Adding explicitly configured mappings...");
       if (hibernateMapping != null)
       {
         try
         {
           MessageDigest digest = java.security.MessageDigest.getInstance("MD5");
           for (String filename : hibernateMapping.split("[\\s,]+"))
           {
             // First try the filename as absolute/relative path
             File file = new File(filename);
             if (!file.exists())
             {
               // If the file was not found, search for it in the resource-directories
               for (Resource resource : project.getResources())
               {
                 file = new File(resource.getDirectory() + File.separator + filename);
                 if (file.exists())
                   break;
               }
             }
             if (file != null && file.exists())
             {
               InputStream is = new FileInputStream(file);
               byte[] buffer = new byte[1024*4]; // copy data in 4MB-chunks
               int i;
               while((i = is.read(buffer)) > -1)
                 digest.update(buffer, 0, i);
               is.close();
               byte[] bytes = digest.digest();
               BigInteger bi = new BigInteger(1, bytes);
               String newMd5 = String.format("%0" + (bytes.length << 1) + "x", bi);
               String oldMd5 = !md5s.containsKey(filename) ? "" : md5s.get(filename);
               if (!newMd5.equals(oldMd5))
               {
                 getLog().debug("Found new or modified mapping-file: " + filename);
                 modified = true;
                 md5s.put(filename, newMd5);
               }
               else
               {
                 getLog().debug(oldMd5 + " -> mapping-file unchanged: " + filename);
               }
               getLog().debug("Adding mappings from XML-configurationfile: " + file);
               config.addFile(file);
             }
             else
               throw new MojoFailureException("File " + filename + " could not be found in any of the configured resource-directories!");
           }
         }
         catch (NoSuchAlgorithmException e)
         {
           throw new MojoFailureException("Cannot calculate MD5 sums!", e);
         }
         catch (FileNotFoundException e)
         {
           throw new MojoFailureException("Cannot calculate MD5 sums!", e);
         }
         catch (IOException e)
         {
           throw new MojoFailureException("Cannot calculate MD5 sums!", e);
         }
       }
 
       getLog().debug("Adding annotated classes to hibernate-mapping-configuration...");
       // build annotated packages
       Set<String> packages = new HashSet<String>();
       for (Class<?> annotatedClass : classes)
       {
         String packageName = annotatedClass.getPackage().getName();
         if (!packages.contains(packageName))
         {
           getLog().debug("Add package " + packageName);
           packages.add(packageName);
           config.addPackage(packageName);
           getLog().debug("type definintions" + config.getTypeDefs());
         }
         getLog().debug("Class " + annotatedClass);
         config.addAnnotatedClass(annotatedClass);
       }
 
       Target target = null;
       try
       {
         target = Target.valueOf(this.target.toUpperCase());
       }
       catch (IllegalArgumentException e)
       {
         getLog().error("Invalid value for configuration-option \"target\": " + this.target);
         getLog().error("Valid values are: NONE, SCRIPT, EXPORT, BOTH");
         throw new MojoExecutionException("Invalid value for configuration-option \"target\"");
       }
       Type type = null;
       try
       {
         type = Type.valueOf(this.type.toUpperCase());
       }
       catch (IllegalArgumentException e)
       {
         getLog().error("Invalid value for configuration-option \"type\": " + this.type);
         getLog().error("Valid values are: NONE, CREATE, DROP, BOTH");
         throw new MojoExecutionException("Invalid value for configuration-option \"type\"");
       }
 
 
       if (config.getProperty(DIALECT) == null)
         throw new MojoFailureException("hibernate-dialect must be set!");
 
 
       if (target.equals(Target.SCRIPT) || target.equals(Target.NONE))
       {
         project.getProperties().setProperty(EXPORT_SKIPPED_PROPERTY, "true");
       }
       if (
           !modified
           && !target.equals(Target.SCRIPT)
           && !target.equals(Target.NONE)
           && !force
         )
       {
         getLog().info("No modified annotated classes or mapping-files found and dialect unchanged.");
         getLog().info("Skipping schema generation!");
         project.getProperties().setProperty(EXPORT_SKIPPED_PROPERTY, "true");
         return;
       }
 
 
       if ( config.getProperties().containsKey(NAMING_STRATEGY))
       {
         String namingStrategy = config.getProperty(NAMING_STRATEGY);
         getLog().debug("Explicitly set NamingStrategy: " + namingStrategy);
         try
         {
           List runtimeClasspathElements = project.getRuntimeClasspathElements();
           URL[] runtimeUrls = new URL[runtimeClasspathElements.size()];
           for (int i = 0; i < runtimeClasspathElements.size(); i++)
           {
             String element = (String) runtimeClasspathElements.get(i);
             runtimeUrls[i] = new File(element).toURI().toURL();
           }
           URLClassLoader newLoader = new URLClassLoader(
               runtimeUrls,
               Thread.currentThread().getContextClassLoader()
               );
           @SuppressWarnings("unchecked")
           Class<NamingStrategy> namingStrategyClass =
               (Class<NamingStrategy>) newLoader.loadClass(namingStrategy);
           config.setNamingStrategy(namingStrategyClass.newInstance());
         }
         catch (Exception e)
         {
           getLog().error("Error setting NamingStrategy", e);
           throw new MojoExecutionException(e.getMessage());
         }
       }
 
 
       Environment.verifyProperties(config.getProperties());
       ConfigurationHelper.resolvePlaceHolders(config.getProperties());
       registry =
           (StandardServiceRegistryImpl)
           new StandardServiceRegistryBuilder()
               .applySettings(config.getProperties())
               .build();
 
       config.buildMappings();
 
       if (envers)
       {
         getLog().info("Automatic auditing via hibernate-envers enabled!");
         AuditConfiguration.getFor(config);
       }
 
       SchemaExport export = new SchemaExport(registry, config);
       export.setDelimiter(delimiter);
       export.setFormat(format);
 
       File outF = new File(outputFile);
 
       if (!outF.isAbsolute())
       {
         // Interpret relative file path relative to build directory
         outF = new File(buildDirectory, outputFile);
         getLog().info("Adjusted relative path, resulting path is " + outF.getPath());
       }
 
       // Ensure that directory path for specified file exists
       File outFileParentDir = outF.getParentFile();
       if (null != outFileParentDir && !outFileParentDir.exists())
       {
         try
         {
           getLog().info("Creating directory path for output file:" + outFileParentDir.getPath());
           outFileParentDir.mkdirs();
         }
         catch (Exception e)
         {
           getLog().error("Error creating directory path for output file: " + e.getLocalizedMessage());
         }
       }
 
       export.setOutputFile(outF.getPath());
       export.execute(target, type);
 
       for (Object exception : export.getExceptions())
         getLog().debug(exception.toString());
     }
     finally
     {
       /** Stop Log-Capturing */
       MavenLogAppender.endPluginLog(this);
 
       /** Restore the old class-loader (TODO: is this really necessary?) */
       Thread.currentThread().setContextClassLoader(contextClassLoader);
 
       if (registry != null)
         registry.destroy();
     }
 
     /** Write md5-sums for annotated classes to file */
     try
     {
       FileOutputStream fos = new FileOutputStream(saved);
       ObjectOutputStream oos = new ObjectOutputStream(fos);
       oos.writeObject(md5s);
       oos.close();
       fos.close();
     }
     catch (Exception e)
     {
       getLog().error("Cannot write md5-sums to file: " + e);
     }
   }
 
   private ParsedPersistenceXmlDescriptor getPersistenceUnitDescriptor(
       String name,
       Properties properties,
       ClassLoaderService loader
       )
       throws
         MojoFailureException
   {
     PersistenceXmlParser parser =
         new PersistenceXmlParser(
             loader,
             PersistenceUnitTransactionType.RESOURCE_LOCAL
              );
 
     List<ParsedPersistenceXmlDescriptor> units = parser.doResolve(properties);
 
     if (name == null)
     {
       switch (units.size())
       {
         case 0:
           getLog().info("Found no META-INF/persistence.xml.");
           return null;
         case 1:
           getLog().info("Using persistence-unit " + units.get(0).getName());
           return units.get(0);
         default:
           getLog().warn("No name provided and multiple persistence units found:");
           for (ParsedPersistenceXmlDescriptor unit : units)
             getLog().warn(" - " + unit.getName());
           return null;
       }
 
     }
 
     for (ParsedPersistenceXmlDescriptor unit : units)
     {
       getLog().debug("Found persistence-unit " + unit.getName());
       if (!unit.getName().equals(name))
         continue;
 
       // See if we (Hibernate) are the persistence provider
       if (!ProviderChecker.isProvider(unit, properties))
       {
         getLog().debug("Wrong provider: " + unit.getProviderClassName());
         continue;
       }
 
       getLog().info("Using persistence-unit " + unit.getName());
       return unit;
     }
 
     throw new MojoFailureException("Could not find persistence-unit " + name);
   }
 
 
   static final class MavenProjectClassLoaderService implements ClassLoaderService
   {
     final private ClassLoader loader;
 
 
     public MavenProjectClassLoaderService(ClassLoader loader)
     {
       this.loader = loader;
     }
 
 
     @Override
     public <T> Class<T> classForName(String name)
     {
       try
       {
         return (Class<T>)loader.loadClass(name);
       }
       catch (ClassNotFoundException e)
       {
         throw new ClassLoadingException( "Unable to load class [" + name + "]", e );
       }
     }
 
     @Override
     public URL locateResource(String name)
     {
       return loader.getResource(name);
     }
 
     @Override
     public InputStream locateResourceStream(String name)
     {
       return loader.getResourceAsStream(name);
     }
 
     @Override
     public List<URL> locateResources(String name)
     {
       try
       {
         return Collections.list(loader.getResources(name));
       }
       catch (IOException e)
       {
         return Collections.EMPTY_LIST;
       }
     }
 
     @Override
     public <S> LinkedHashSet<S> loadJavaServices(Class<S> serviceContract)
     {
       throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
     }
 
     @Override
     public void stop() { }
 
   }
 
 
   /**
    * Needed, because DriverManager won't pick up drivers, that were not
    * loaded by the system-classloader!
    * See:
    * http://stackoverflow.com/questions/288828/how-to-use-a-jdbc-driver-fromodifiedm-an-arbitrary-location
    */
   static final class DriverProxy implements Driver
   {
     private final Driver target;
 
     DriverProxy(Driver target)
     {
       if (target == null)
         throw new NullPointerException();
       this.target = target;
     }
 
     public java.sql.Driver getTarget()
     {
       return target;
     }
 
     @Override
     public boolean acceptsURL(String url) throws SQLException
     {
       return target.acceptsURL(url);
     }
 
     @Override
     public java.sql.Connection connect(
         String url,
         java.util.Properties info
       )
       throws
         SQLException
     {
       return target.connect(url, info);
     }
 
     @Override
     public int getMajorVersion()
     {
       return target.getMajorVersion();
     }
 
     @Override
     public int getMinorVersion()
     {
       return target.getMinorVersion();
     }
 
     @Override
     public DriverPropertyInfo[] getPropertyInfo(
         String url,
         Properties info
       )
       throws
         SQLException
     {
       return target.getPropertyInfo(url, info);
     }
 
     @Override
     public boolean jdbcCompliant()
     {
       return target.jdbcCompliant();
     }
 
     /**
      * This Method cannot be annotated with @Override, becaus the plugin
      * will not compile then under Java 1.6!
      */
     public Logger getParentLogger() throws SQLFeatureNotSupportedException
     {
       throw new SQLFeatureNotSupportedException("Not supported, for backward-compatibility with Java 1.6");
     }
 
     @Override
     public String toString()
     {
       return "Proxy: " + target;
     }
 
     @Override
     public int hashCode()
     {
       return target.hashCode();
     }
 
     @Override
     public boolean equals(Object obj)
     {
       if (!(obj instanceof DriverProxy))
         return false;
       DriverProxy other = (DriverProxy) obj;
       return this.target.equals(other.target);
     }
   }
 }