Fixed NullPointerException in ModificationTracker
[hibernate4-maven-plugin] / src / main / java / de / juplo / plugins / hibernate / AbstractSchemaMojo.java
index 4135b61..e121f2a 100644 (file)
@@ -6,13 +6,13 @@ import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.net.MalformedURLException;
 import java.net.URL;
-import java.net.URLClassLoader;
 import java.security.NoSuchAlgorithmException;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.Iterator;
-import java.util.LinkedList;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
@@ -33,6 +33,8 @@ import org.apache.maven.project.MavenProject;
 import org.hibernate.boot.MetadataBuilder;
 import org.hibernate.boot.MetadataSources;
 import org.hibernate.boot.cfgxml.internal.ConfigLoader;
+import org.hibernate.boot.cfgxml.spi.LoadedConfig;
+import org.hibernate.boot.cfgxml.spi.MappingReference;
 import org.hibernate.boot.model.naming.ImplicitNamingStrategy;
 import org.hibernate.boot.model.naming.PhysicalNamingStrategy;
 import org.hibernate.boot.registry.BootstrapServiceRegistry;
@@ -40,13 +42,17 @@ import org.hibernate.boot.registry.BootstrapServiceRegistryBuilder;
 import org.hibernate.boot.registry.StandardServiceRegistry;
 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.selector.spi.StrategySelector;
 import org.hibernate.boot.spi.MetadataImplementor;
 import static org.hibernate.cfg.AvailableSettings.DIALECT;
 import static org.hibernate.cfg.AvailableSettings.DRIVER;
+import static org.hibernate.cfg.AvailableSettings.FORMAT_SQL;
+import static org.hibernate.cfg.AvailableSettings.HBM2DLL_CREATE_NAMESPACES;
 import static org.hibernate.cfg.AvailableSettings.IMPLICIT_NAMING_STRATEGY;
 import static org.hibernate.cfg.AvailableSettings.PASS;
 import static org.hibernate.cfg.AvailableSettings.PHYSICAL_NAMING_STRATEGY;
+import static org.hibernate.cfg.AvailableSettings.SHOW_SQL;
 import static org.hibernate.cfg.AvailableSettings.USER;
 import static org.hibernate.cfg.AvailableSettings.URL;
 import org.hibernate.engine.jdbc.connections.spi.ConnectionProvider;
@@ -70,10 +76,18 @@ import org.scannotation.AnnotationDB;
  */
 public abstract class AbstractSchemaMojo extends AbstractMojo
 {
-  public final static String EXPORT_SKIPPED_PROPERTY = "hibernate.export.skipped";
+  public final static String EXPORT = "hibernate.schema.export";
+  public final static String DELIMITER = "hibernate.schema.delimiter";
+  public final static String OUTPUTDIRECTORY = "project.build.outputDirectory";
+  public final static String SCAN_CLASSES = "hibernate.schema.scan.classes";
+  public final static String SCAN_DEPENDENCIES = "hibernate.schema.scan.dependencies";
+  public final static String SCAN_TESTCLASSES = "hibernate.schema.scan.test_classes";
+  public final static String TEST_OUTPUTDIRECTORY = "project.build.testOutputDirectory";
+  public final static String SKIPPED = "hibernate.schema.skipped";
 
   private final static Pattern SPLIT = Pattern.compile("[^,\\s]+");
 
+  private final Set<String> packages = new HashSet<String>();
 
   /**
    * The maven project.
@@ -97,27 +111,156 @@ public abstract class AbstractSchemaMojo extends AbstractMojo
    */
   String buildDirectory;
 
+
+  /** Parameters to configure the genaration of the SQL *********************/
+
   /**
-   * Classes-Directory to scan.
+   * Export the database-schma to the database.
+   * If set to <code>false</code>, only the SQL-script is created and the
+   * database is not touched.
    * <p>
-   * This parameter defaults to the maven build-output-directory for classes.
-   * Additionally, all dependencies are scanned for annotated classes.
+   * <strong>Important:</strong>
+   * This configuration value can only be configured through the
+   * <code>pom.xml</code>, or by the definition of a system-property, because
+   * it is not known by Hibernate nor JPA and, hence, not picked up from
+   * their configuration!
    *
-   * @parameter property="project.build.outputDirectory"
+   * @parameter property="hibernate.schema.export" default-value="true"
+   * @since 2.0
+   */
+  Boolean export;
+
+  /**
+   * Skip execution
+   * <p>
+   * If set to <code>true</code>, the execution is skipped.
+   * <p>
+   * A skipped execution is signaled via the maven-property
+   * <code>${hibernate.schema.skipped}</code>.
+   * <p>
+   * The execution is skipped automatically, if no modified or newly added
+   * annotated classes are found and the dialect was not changed.
+   * <p>
+   * <strong>Important:</strong>
+   * This configuration value can only be configured through the
+   * <code>pom.xml</code>, or by the definition of a system-property, because
+   * it is not known by Hibernate nor JPA and, hence, not picked up from
+   * their configuration!
+   *
+   * @parameter property="hibernate.schema.skip" default-value="${maven.test.skip}"
    * @since 1.0
    */
-  private String outputDirectory;
+  private boolean skip;
 
   /**
-   * Whether to scan test-classes too, or not.
+   * Force execution
    * <p>
-   * If this parameter is set to <code>true</code> the test-classes of the
-   * artifact will be scanned for hibernate-annotated classes additionally.
+   * 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>.
+   * <p>
+   * <strong>Important:</strong>
+   * This configuration value can only be configured through the
+   * <code>pom.xml</code>, or by the definition of a system-property, because
+   * it is not known by Hibernate nor JPA and, hence, not picked up from
+   * their configuration!
    *
-   * @parameter property="hibernate.export.scan_testclasses" default-value="false"
-   * @since 1.0.1
+   * @parameter property="hibernate.schema.force" default-value="false"
+   * @since 1.0
+   */
+  private boolean force;
+
+  /**
+   * Hibernate dialect.
+   *
+   * @parameter property="hibernate.dialect"
+   * @since 1.0
+   */
+  private String dialect;
+
+  /**
+   * Delimiter in output-file.
+   * <p>
+   * <strong>Important:</strong>
+   * This configuration value can only be configured through the
+   * <code>pom.xml</code>, or by the definition of a system-property, because
+   * it is not known by Hibernate nor JPA and, hence, not picked up from
+   * their configuration!
+   *
+   * @parameter property="hibernate.schema.delimiter" default-value=";"
+   * @since 1.0
+   */
+  String delimiter;
+
+  /**
+   * Show the generated SQL in the command-line output.
+   *
+   * @parameter property="hibernate.show_sql"
+   * @since 1.0
+   */
+  Boolean show;
+
+  /**
+   * Format output-file.
+   *
+   * @parameter property="hibernate.format_sql"
+   * @since 1.0
+   */
+  Boolean format;
+
+  /**
+   * Specifies whether to automatically create also the database schema/catalog.
+   *
+   * @parameter property="hibernate.hbm2dll.create_namespaces" default-value="false"
+   * @since 2.0
+   */
+  Boolean createNamespaces;
+
+  /**
+   * Implicit naming strategy
+   *
+   * @parameter property="hibernate.implicit_naming_strategy"
+   * @since 2.0
+   */
+  private String implicitNamingStrategy;
+
+  /**
+   * Physical naming strategy
+   *
+   * @parameter property="hibernate.physical_naming_strategy"
+   * @since 2.0
+   */
+  private String physicalNamingStrategy;
+
+  /**
+   * Wether the project should be scanned for annotated-classes, or not
+   * <p>
+   * This parameter is intended to allow overwriting of the parameter
+   * <code>exclude-unlisted-classes</code> of a <code>persistence-unit</code>.
+   * If not specified, it defaults to <code>true</code>
+   *
+   * @parameter property="hibernate.schema.scan.classes"
+   * @since 2.0
    */
-  private boolean scanTestClasses;
+  private Boolean scanClasses;
+
+  /**
+   * Classes-Directory to scan.
+   * <p>
+   * This parameter defaults to the maven build-output-directory for classes.
+   * Additionally, all dependencies are scanned for annotated classes.
+   * <p>
+   * <strong>Important:</strong>
+   * This configuration value can only be configured through the
+   * <code>pom.xml</code>, or by the definition of a system-property, because
+   * it is not known by Hibernate nor JPA and, hence, not picked up from
+   * their configuration!
+   *
+   * @parameter property="project.build.outputDirectory"
+   * @since 1.0
+   */
+  private String outputDirectory;
 
   /**
    * Dependency-Scopes, that should be scanned for annotated classes.
@@ -125,7 +268,7 @@ public abstract class AbstractSchemaMojo extends AbstractMojo
    * 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>md5s
+   * <p>
    * If you do not want any dependencies to be scanned for annotated
    * classes, set this parameter to <code>none</code>.
    * <p>
@@ -133,11 +276,29 @@ public abstract class AbstractSchemaMojo extends AbstractMojo
    * 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"
+   * @parameter property="hibernate.schema.scan.dependencies" default-value="compile"
    * @since 1.0.3
    */
   private String scanDependencies;
 
+  /**
+   * Whether to scan the test-branch of the project for annotated classes, 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.
+   * <p>
+   * <strong>Important:</strong>
+   * This configuration value can only be configured through the
+   * <code>pom.xml</code>, or by the definition of a system-property, because
+   * it is not known by Hibernate nor JPA and, hence, not picked up from
+   * their configuration!
+   *
+   * @parameter property="hibernate.schema.scan.test_classes" default-value="false"
+   * @since 1.0.1
+   */
+  private Boolean scanTestClasses;
+
   /**
    * Test-Classes-Directory to scan.
    * <p>
@@ -146,40 +307,20 @@ public abstract class AbstractSchemaMojo extends AbstractMojo
    * <p>
    * This parameter is only used, when <code>scanTestClasses</code> is set
    * to <code>true</code>!
+   * <p>
+   * <strong>Important:</strong>
+   * This configuration value can only be configured through the
+   * <code>pom.xml</code>, or by the definition of a system-property, because
+   * it is not known by Hibernate nor JPA and, hence, not picked up from
+   * their configuration!
    *
    * @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;
+  /** Conection parameters *************************************************/
 
   /**
    * SQL-Driver name.
@@ -213,29 +354,8 @@ public abstract class AbstractSchemaMojo extends AbstractMojo
    */
   private String password;
 
-  /**
-   * Hibernate dialect.
-   *
-   * @parameter property="hibernate.dialect"
-   * @since 1.0
-   */
-  private String dialect;
-
-  /**
-   * Implicit naming strategy
-   *
-   * @parameter property=IMPLICIT_NAMING_STRATEGY
-   * @since 2.0
-   */
-  private String implicitNamingStrategy;
 
-  /**
-   * Physical naming strategy
-   *
-   * @parameter property=PHYSICAL_NAMING_STRATEGY
-   * @since 2.0
-   */
-  private String physicalNamingStrategy;
+  /** Parameters to locate configuration sources ****************************/
 
   /**
    * Path to a file or name of a ressource with hibernate properties.
@@ -302,8 +422,8 @@ public abstract class AbstractSchemaMojo extends AbstractMojo
   private String mappings;
 
 
-  @Override
-  public final void execute()
+
+  public final void execute(String filename)
     throws
       MojoFailureException,
       MojoExecutionException
@@ -311,14 +431,14 @@ public abstract class AbstractSchemaMojo extends AbstractMojo
     if (skip)
     {
       getLog().info("Execution of hibernate-maven-plugin was skipped!");
-      project.getProperties().setProperty(EXPORT_SKIPPED_PROPERTY, "true");
+      project.getProperties().setProperty(SKIPPED, "true");
       return;
     }
 
     ModificationTracker tracker;
     try
     {
-      tracker = new ModificationTracker(buildDirectory, getLog());
+      tracker = new ModificationTracker(buildDirectory, filename, getLog());
     }
     catch (NoSuchAlgorithmException e)
     {
@@ -336,10 +456,13 @@ public abstract class AbstractSchemaMojo extends AbstractMojo
       /** Load checksums for old mapping and configuration */
       tracker.load();
 
-      /** Create a BootstrapServiceRegistry with special ClassLoader */
+      /** Create the ClassLoader */
+      MutableClassLoader classLoader = createClassLoader();
+
+      /** Create a BootstrapServiceRegistry with the created ClassLoader */
       BootstrapServiceRegistry bootstrapServiceRegitry =
           new BootstrapServiceRegistryBuilder()
-              .applyClassLoader(createClassLoader())
+              .applyClassLoader(classLoader)
               .build();
       ClassLoaderService classLoaderService =
           bootstrapServiceRegitry.getService(ClassLoaderService.class);
@@ -349,14 +472,19 @@ public abstract class AbstractSchemaMojo extends AbstractMojo
 
       /** Loading and merging configuration */
       properties.putAll(loadProperties(configLoader));
-      properties.putAll(loadConfig(configLoader));
-      properties.putAll(loadPersistenceUnit(classLoaderService, properties));
+      LoadedConfig config = loadConfig(configLoader);
+      if (config != null)
+        properties.putAll(config.getConfigurationValues());
+      ParsedPersistenceXmlDescriptor unit =
+          loadPersistenceUnit(classLoaderService, properties);
+      if (unit != null)
+        properties.putAll(unit.getProperties());
 
       /** Overwriting/Completing configuration */
-      configure(properties);
+      configure(properties, tracker);
 
       /** Check configuration for modifications */
-      if(tracker.check(properties))
+      if(tracker.track(properties))
         getLog().debug("Configuration has changed.");
       else
         getLog().debug("Configuration unchanged.");
@@ -367,10 +495,118 @@ public abstract class AbstractSchemaMojo extends AbstractMojo
               .applySettings(properties)
               .addService(ConnectionProvider.class, connectionProvider)
               .build();
-
-      /** Load Mappings */
       MetadataSources sources = new MetadataSources(serviceRegistry);
-      addAnnotatedClasses(sources, classLoaderService, tracker);
+
+      /** Add the remaining class-path-elements */
+      completeClassPath(classLoader);
+
+      /** Apply mappings from hibernate-configuration, if present */
+      if (config != null)
+      {
+        for (MappingReference mapping : config.getMappingReferences())
+          mapping.apply(sources);
+      }
+
+      Set<String> classes;
+      if (unit == null)
+      {
+        /** No persistent unit: default behaviour */
+        if (scanClasses == null)
+          scanClasses = true;
+        Set<URL> urls = new HashSet<URL>();
+        if (scanClasses)
+          addRoot(urls, outputDirectory);
+        if (scanTestClasses)
+          addRoot(urls, testOutputDirectory);
+        addDependencies(urls);
+        classes = scanUrls(urls);
+      }
+      else
+      {
+        /** Follow configuration in persisten unit */
+        if (scanClasses == null)
+          scanClasses = !unit.isExcludeUnlistedClasses();
+        Set<URL> urls = new HashSet<URL>();
+        if (scanClasses)
+        {
+          /**
+           * Scan the root of the persiten unit and configured jars for
+           * annotated classes
+           */
+          urls.add(unit.getPersistenceUnitRootUrl());
+          for (URL url : unit.getJarFileUrls())
+            urls.add(url);
+        }
+        if (scanTestClasses)
+          addRoot(urls, testOutputDirectory);
+        classes = scanUrls(urls);
+        for (String className : unit.getManagedClassNames())
+          classes.add(className);
+        /**
+         * Add mappings from the default mapping-file
+         * <code>META-INF/orm.xml</code>, if present
+         */
+        boolean error = false;
+        InputStream is;
+        is = classLoader.getResourceAsStream("META-INF/orm.xml");
+        if (is != null)
+        {
+          getLog().info("Adding default JPA-XML-mapping from META-INF/orm.xml");
+          try
+          {
+            tracker.track("META-INF/orm.xml", is);
+            sources.addResource("META-INF/orm.xml");
+          }
+          catch (IOException e)
+          {
+            getLog().error("cannot read META-INF/orm.xml: " + e);
+            error = true;
+          }
+        }
+        else
+        {
+          getLog().debug("no META-INF/orm.xml found");
+        }
+        /**
+         * Add mappings from files, that are explicitly configured in the
+         * persistence unit
+         */
+        for (String mapping : unit.getMappingFileNames())
+        {
+          getLog().info("Adding explicitly configured mapping from " + mapping);
+          is = classLoader.getResourceAsStream(mapping);
+          if (is != null)
+          {
+            try
+            {
+              tracker.track(mapping, is);
+              sources.addResource(mapping);
+            }
+            catch (IOException e)
+            {
+              getLog().info("cannot read mapping-file " + mapping + ": " + e);
+              error = true;
+            }
+          }
+          else
+          {
+            getLog().error("cannot find mapping-file " + mapping);
+            error = true;
+          }
+        }
+        if (error)
+          throw new MojoFailureException(
+              "error, while reading mappings configured in persistence-unit \"" +
+              unit.getName() +
+              "\""
+              );
+      }
+
+      /** Add the configured/collected annotated classes */
+      for (String className : classes)
+        addAnnotated(className, sources, classLoaderService, tracker);
+
+      /** Add explicitly configured classes */
       addMappings(sources, tracker);
 
       /** Skip execution, if mapping and configuration is unchanged */
@@ -384,7 +620,7 @@ public abstract class AbstractSchemaMojo extends AbstractMojo
         else
         {
           getLog().info("Skipping schema generation!");
-          project.getProperties().setProperty(EXPORT_SKIPPED_PROPERTY, "true");
+          project.getProperties().setProperty(SKIPPED, "true");
           return;
         }
       }
@@ -418,7 +654,37 @@ public abstract class AbstractSchemaMojo extends AbstractMojo
             );
       }
 
-      build((MetadataImplementor)metadataBuilder.build());
+      /**
+       * Change class-loader of current thread.
+       * This is necessary, because still not all parts of Hibernate 5 use
+       * the newly introduced ClassLoaderService and will fail otherwise!
+       */
+      Thread thread = Thread.currentThread();
+      ClassLoader contextClassLoader = thread.getContextClassLoader();
+      try
+      {
+        thread.setContextClassLoader(classLoader);
+        build((MetadataImplementor)metadataBuilder.build());
+      }
+      finally
+      {
+        thread.setContextClassLoader(contextClassLoader);
+      }
+    }
+    catch (MojoExecutionException e)
+    {
+      tracker.failed();
+      throw e;
+    }
+    catch (MojoFailureException e)
+    {
+      tracker.failed();
+      throw e;
+    }
+    catch (RuntimeException e)
+    {
+      tracker.failed();
+      throw e;
     }
     finally
     {
@@ -440,40 +706,56 @@ public abstract class AbstractSchemaMojo extends AbstractMojo
       MojoExecutionException;
 
 
-  private URLClassLoader createClassLoader() throws MojoExecutionException
+  private MutableClassLoader createClassLoader() throws MojoExecutionException
   {
     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>();
+      LinkedHashSet<URL> urls = new LinkedHashSet<URL>();
       File file;
+
       file = new File(testOutputDirectory);
       if (!file.exists())
       {
-        getLog().info("creating test-output-directory: " + testOutputDirectory);
+        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);
+        getLog().info("Creating output-directory: " + outputDirectory);
         file.mkdirs();
       }
       urls.add(file.toURI().toURL());
+
+      return new MutableClassLoader(urls, getLog());
+    }
+    catch (Exception e)
+    {
+      getLog().error("Error while creating ClassLoader!", e);
+      throw new MojoExecutionException(e.getMessage());
+    }
+  }
+
+  private void completeClassPath(MutableClassLoader classLoader)
+      throws
+        MojoExecutionException
+  {
+    try
+    {
+      getLog().debug("Completing class-paths of the ClassLoader for project-dependencies...");
+      List<String> classpathFiles = project.getCompileClasspathElements();
+      if (scanTestClasses)
+        classpathFiles.addAll(project.getTestClasspathElements());
+      LinkedHashSet<URL> urls = new LinkedHashSet<URL>();
       for (String pathElement : classpathFiles)
       {
         getLog().debug("Dependency: " + pathElement);
         urls.add(new File(pathElement).toURI().toURL());
       }
-      return
-          new URLClassLoader(
-              urls.toArray(new URL[urls.size()]),
-              getClass().getClassLoader()
-              );
+      classLoader.add(urls);
     }
     catch (Exception e)
     {
@@ -520,7 +802,7 @@ public abstract class AbstractSchemaMojo extends AbstractMojo
     }
   }
 
-  private Map loadConfig(ConfigLoader configLoader)
+  private LoadedConfig loadConfig(ConfigLoader configLoader)
       throws MojoExecutionException
   {
     /** Try to read configuration from configuration-file */
@@ -528,15 +810,12 @@ public abstract class AbstractSchemaMojo extends AbstractMojo
     {
       try
       {
-        return
-            configLoader
-                .loadConfigXmlResource("hibernate.cfg.xml")
-                .getConfigurationValues();
+        return configLoader.loadConfigXmlResource("hibernate.cfg.xml");
       }
       catch (ConfigurationException e)
       {
         getLog().debug(e.getMessage());
-        return Collections.EMPTY_MAP;
+        return null;
       }
     }
     else
@@ -547,13 +826,12 @@ public abstract class AbstractSchemaMojo extends AbstractMojo
         if (file.exists())
         {
           getLog().info("Reading configuration from file " + hibernateConfig + "...");
-          return configLoader.loadConfigXmlFile(file).getConfigurationValues();
+          return configLoader.loadConfigXmlFile(file);
         }
         else
-          return
-              configLoader
-                  .loadConfigXmlResource(hibernateConfig)
-                  .getConfigurationValues();
+        {
+          return configLoader.loadConfigXmlResource(hibernateConfig);
+        }
       }
       catch (ConfigurationException e)
       {
@@ -563,18 +841,50 @@ public abstract class AbstractSchemaMojo extends AbstractMojo
     }
   }
 
-  private void configure(Properties properties)
+  private void configure(Properties properties, ModificationTracker tracker)
       throws MojoFailureException
   {
-    /** Overwrite values from properties-file or set, if given */
+    /**
+     * Special treatment for the configuration-value "export": if it is
+     * switched to "true", the genearation fo the schema should be forced!
+     */
+    if (tracker.check(EXPORT, export.toString()) && export)
+      tracker.touch();
+
+    /**
+     * Configure the generation of the SQL.
+     * Overwrite values from properties-file if the configuration parameter is
+     * known to Hibernate.
+     */
+    dialect = configure(properties, dialect, DIALECT);
+    tracker.track(DELIMITER, delimiter); // << not reflected in hibernate configuration!
+    format = configure(properties, format, FORMAT_SQL);
+    createNamespaces = configure(properties, createNamespaces, HBM2DLL_CREATE_NAMESPACES);
+    implicitNamingStrategy = configure(properties, implicitNamingStrategy, IMPLICIT_NAMING_STRATEGY);
+    physicalNamingStrategy = configure(properties, physicalNamingStrategy, PHYSICAL_NAMING_STRATEGY);
+    tracker.track(OUTPUTDIRECTORY, outputDirectory); // << not reflected in hibernate configuration!
+    tracker.track(SCAN_DEPENDENCIES, scanDependencies); // << not reflected in hibernate configuration!
+    tracker.track(SCAN_TESTCLASSES, scanTestClasses.toString()); // << not reflected in hibernate configuration!
+    tracker.track(TEST_OUTPUTDIRECTORY, testOutputDirectory); // << not reflected in hibernate configuration!
+
+    /**
+     * Special treatment for the configuration-value "show": a change of its
+     * configured value should not lead to a regeneration of the database
+     * schama!
+     */
+    if (show == null)
+      show = Boolean.valueOf(properties.getProperty(SHOW_SQL));
+    else
+      properties.setProperty(SHOW_SQL, show.toString());
 
-    configure(properties, driver, DRIVER, JDBC_DRIVER);
-    configure(properties, url, URL, JDBC_URL);
-    configure(properties, username, USER, JDBC_USER);
-    configure(properties, password, PASS, JDBC_PASSWORD);
-    configure(properties, dialect, DIALECT);
-    configure(properties, implicitNamingStrategy, IMPLICIT_NAMING_STRATEGY);
-    configure(properties, physicalNamingStrategy, PHYSICAL_NAMING_STRATEGY);
+    /**
+     * Configure the connection parameters.
+     * Overwrite values from properties-file.
+     */
+    driver = configure(properties, driver, DRIVER, JDBC_DRIVER);
+    url = configure(properties, url, URL, JDBC_URL);
+    username = configure(properties, username, USER, JDBC_USER);
+    password = configure(properties, password, PASS, JDBC_PASSWORD);
 
     if (properties.isEmpty())
     {
@@ -587,26 +897,30 @@ public abstract class AbstractSchemaMojo extends AbstractMojo
       getLog().info("  " + entry.getKey() + " = " + entry.getValue());
   }
 
-  private void configure(
+  private String configure(
       Properties properties,
       String value,
       String key,
       String alternativeKey
       )
   {
-    configure(properties, value, key);
-    if (properties.containsKey(key) && properties.containsKey(alternativeKey))
+    value = configure(properties, value, key);
+    if (value == null)
+      return properties.getProperty(alternativeKey);
+
+    if (properties.containsKey(alternativeKey))
     {
       getLog().warn(
           "Ignoring property " + alternativeKey + "=" +
           properties.getProperty(alternativeKey) + " in favour for property " +
           key + "=" + properties.getProperty(key)
           );
-      properties.remove(JDBC_DRIVER);
+      properties.remove(alternativeKey);
     }
+    return properties.getProperty(alternativeKey);
   }
 
-  private void configure(Properties properties, String value, String key)
+  private String configure(Properties properties, String value, String key)
   {
     if (value != null)
     {
@@ -619,6 +933,23 @@ public abstract class AbstractSchemaMojo extends AbstractMojo
         getLog().debug("Using the value " + value + " for property " + key);
       properties.setProperty(key, value);
     }
+    return properties.getProperty(key);
+  }
+
+  private boolean configure(Properties properties, Boolean value, String key)
+  {
+    if (value != null)
+    {
+      if (properties.containsKey(key))
+        getLog().debug(
+            "Overwriting property " + key + "=" + properties.getProperty(key) +
+            " with the value " + value
+            );
+      else
+        getLog().debug("Using the value " + value + " for property " + key);
+      properties.setProperty(key, value.toString());
+    }
+    return Boolean.valueOf(properties.getProperty(key));
   }
 
   private void addMappings(MetadataSources sources, ModificationTracker tracker)
@@ -648,10 +979,10 @@ public abstract class AbstractSchemaMojo extends AbstractMojo
             if (file.isDirectory())
               // TODO: add support to read all mappings under a directory
               throw new MojoFailureException(file.getAbsolutePath() + " is a directory");
-            if (tracker.check(filename, new FileInputStream(file)))
+            if (tracker.track(filename, new FileInputStream(file)))
               getLog().debug("Found new or modified mapping-file: " + filename);
             else
-              getLog().debug("mapping-file unchanged: " + filename);
+              getLog().debug("Mapping-file unchanged: " + filename);
 
             sources.addFile(file);
           }
@@ -666,60 +997,65 @@ public abstract class AbstractSchemaMojo extends AbstractMojo
     }
   }
 
-  private void addAnnotatedClasses(
-      MetadataSources sources,
-      ClassLoaderService classLoaderService,
-      ModificationTracker tracker
-      )
-      throws
-        MojoFailureException,
-        MojoExecutionException
-
+  private void addRoot(Set<URL> urls, String path) throws MojoFailureException
   {
     try
     {
-      AnnotationDB db = new AnnotationDB();
-      File dir;
-
-      dir = new File(outputDirectory);
+      File dir = new File(outputDirectory);
       if (dir.exists())
       {
-        getLog().info("Scanning directory " + dir.getAbsolutePath() + " for annotated classes...");
-        URL dirUrl = dir.toURI().toURL();
-        db.scanArchives(dirUrl);
-      }
-
-      if (scanTestClasses)
-      {
-        dir = new File(testOutputDirectory);
-        if (dir.exists())
-        {
-          getLog().info("Scanning directory " + dir.getAbsolutePath() + " for annotated classes...");
-          URL dirUrl = dir.toURI().toURL();
-          db.scanArchives(dirUrl);
-        }
+        getLog().info("Adding " + dir.getAbsolutePath() + " to the list of roots to scan...");
+        urls.add(dir.toURI().toURL());
       }
+    }
+    catch (MalformedURLException e)
+    {
+      getLog().error("error while adding the project-root to the list of roots to scan!", e);
+      throw new MojoFailureException(e.getMessage());
+    }
+  }
 
+  private void addDependencies(Set<URL> urls) throws MojoFailureException
+  {
+    try
+    {
       if (scanDependencies != null)
       {
         Matcher matcher = SPLIT.matcher(scanDependencies);
         while (matcher.find())
         {
-          getLog().info("Scanning dependencies for scope " + matcher.group());
+          getLog().info("Adding dependencies from scope " + matcher.group() + " to the list of roots to scan");
           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!");
+              getLog().warn("Cannot add dependency " + artifact.getId() + ": no JAR-file available!");
               continue;
             }
-            getLog().info("Scanning dependency " + artifact.getId() + " for annotated classes...");
-            db.scanArchives(artifact.getFile().toURI().toURL());
+            getLog().info("Adding dependencies from scope " + artifact.getId() + " to the list of roots to scan");
+            urls.add(artifact.getFile().toURI().toURL());
           }
         }
       }
+    }
+    catch (MalformedURLException e)
+    {
+      getLog().error("Error while adding dependencies to the list of roots to scan!", e);
+      throw new MojoFailureException(e.getMessage());
+    }
+  }
+
+  private Set<String> scanUrls(Set<URL> scanRoots)
+      throws
+        MojoFailureException
+  {
+    try
+    {
+      AnnotationDB db = new AnnotationDB();
+      for (URL root : scanRoots)
+        db.scanArchives(root);
 
       Set<String> classes = new HashSet<String>();
       if (db.getAnnotationIndex().containsKey(Entity.class.getName()))
@@ -729,57 +1065,101 @@ public abstract class AbstractSchemaMojo extends AbstractMojo
       if (db.getAnnotationIndex().containsKey(Embeddable.class.getName()))
         classes.addAll(db.getAnnotationIndex().get(Embeddable.class.getName()));
 
-      Set<String> packages = new HashSet<String>();
+      return classes;
+    }
+    catch (Exception e)
+    {
+      getLog().error("Error while scanning!", e);
+      throw new MojoFailureException(e.getMessage());
+    }
+  }
+
+  private void addAnnotated(
+      String name,
+      MetadataSources sources,
+      ClassLoaderService classLoaderService,
+      ModificationTracker tracker
+      )
+      throws
+        MojoFailureException,
+        MojoExecutionException
+  {
+    try
+    {
+      getLog().info("Adding annotated resource: " + name);
+      String packageName = null;
 
-      for (String name : classes)
+      boolean error = false;
+      try
       {
         Class<?> annotatedClass = classLoaderService.classForName(name);
-        String packageName = annotatedClass.getPackage().getName();
-        if (!packages.contains(packageName))
-        {
-          InputStream is =
-              annotatedClass.getResourceAsStream("package-info.class");
-          if (is == null)
-          {
-            // No compiled package-info available: no package-level annotations!
-            getLog().debug("Package " + packageName + " is not annotated.");
-          }
-          else
-          {
-            if (tracker.check(packageName, is))
-              getLog().debug("New or modified package: " + packageName);
-            else
-              getLog().debug("Unchanged package: " + packageName);
-            getLog().info("Adding annotated package " + packageName);
-            sources.addPackage(packageName);
-          }
-          packages.add(packageName);
-        }
         String resourceName = annotatedClass.getName();
         resourceName =
             resourceName.substring(
                 resourceName.lastIndexOf(".") + 1,
                 resourceName.length()
                 ) + ".class";
-        InputStream is =
-            annotatedClass
-                .getResourceAsStream(resourceName);
-        if (tracker.check(name, is))
-          getLog().debug("New or modified class: " + name);
+        InputStream is = annotatedClass.getResourceAsStream(resourceName);
+        if (is != null)
+        {
+          if (tracker.track(name, is))
+            getLog().debug("New or modified class: " + name);
+          else
+            getLog().debug("Unchanged class: " + name);
+          sources.addAnnotatedClass(annotatedClass);
+          packageName = annotatedClass.getPackage().getName();
+        }
+        else
+        {
+          getLog().error("cannot find ressource " + resourceName + " for class " + name);
+          error = true;
+        }
+      }
+      catch(ClassLoadingException e)
+      {
+        packageName = name;
+      }
+      if (error)
+      {
+        throw new MojoExecutionException("error while inspecting annotated class " + name);
+      }
+
+      while (packageName != null)
+      {
+        if (packages.contains(packageName))
+          return;
+        String resource = packageName.replace('.', '/') + "/package-info.class";
+        InputStream is = classLoaderService.locateResourceStream(resource);
+        if (is == null)
+        {
+          // No compiled package-info available: no package-level annotations!
+          getLog().debug("Package " + packageName + " is not annotated.");
+        }
         else
-          getLog().debug("Unchanged class: " + name);
-        getLog().info("Adding annotated class " + annotatedClass);
-        sources.addAnnotatedClass(annotatedClass);
+        {
+          if (tracker.track(packageName, is))
+            getLog().debug("New or modified package: " + packageName);
+          else
+           getLog().debug("Unchanged package: " + packageName);
+          getLog().info("Adding annotations from package " + packageName);
+          sources.addPackage(packageName);
+        }
+        packages.add(packageName);
+        int i = packageName.lastIndexOf('.');
+        if (i < 0)
+          packageName = null;
+        else
+          packageName = packageName.substring(0,i);
       }
     }
     catch (Exception e)
     {
-      getLog().error("Error while scanning!", e);
+      getLog().error("Error while adding the annotated class " + name, e);
       throw new MojoFailureException(e.getMessage());
     }
   }
 
-  private Properties loadPersistenceUnit(
+  private ParsedPersistenceXmlDescriptor loadPersistenceUnit(
       ClassLoaderService classLoaderService,
       Properties properties
       )
@@ -800,10 +1180,10 @@ public abstract class AbstractSchemaMojo extends AbstractMojo
       {
         case 0:
           getLog().info("Found no META-INF/persistence.xml.");
-          return new Properties();
+          return null;
         case 1:
           getLog().info("Using persistence-unit " + units.get(0).getName());
-          return units.get(0).getProperties();
+          return units.get(0);
         default:
           StringBuilder builder = new StringBuilder();
           builder.append("No name provided and multiple persistence units found: ");
@@ -833,7 +1213,7 @@ public abstract class AbstractSchemaMojo extends AbstractMojo
       }
 
       getLog().info("Using persistence-unit " + unit.getName());
-      return unit.getProperties();
+      return unit;
     }
 
     throw new MojoFailureException("Could not find persistence-unit " + persistenceUnit);