Settings in a hibernate.cfg.xml are read
[hibernate4-maven-plugin] / src / main / java / de / juplo / plugins / hibernate4 / Hbm2DdlMojo.java
index f73fa2b..3efa185 100644 (file)
@@ -30,16 +30,16 @@ import java.net.URL;
 import java.net.URLClassLoader;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
-import java.sql.Connection;
 import java.sql.Driver;
-import java.sql.DriverManager;
 import java.sql.DriverPropertyInfo;
 import java.sql.SQLException;
 import java.sql.SQLFeatureNotSupportedException;
+import java.util.Collections;
 import java.util.Comparator;
-import java.util.Enumeration;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.Iterator;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
@@ -52,15 +52,25 @@ 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.cfg.Configuration;
+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.mapping.PersistentClass;
 import org.hibernate.tool.hbm2ddl.SchemaExport;
 import org.hibernate.tool.hbm2ddl.SchemaExport.Type;
 import org.hibernate.tool.hbm2ddl.Target;
@@ -144,6 +154,9 @@ public class Hbm2DdlMojo extends AbstractMojo
    * 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.
@@ -245,13 +258,33 @@ public class Hbm2DdlMojo extends AbstractMojo
   private String hibernateNamingStrategy;
 
   /**
-   * Path to Hibernate configuration file.
+   * Path to Hibernate properties file.
    *
    * @parameter default-value="${project.build.outputDirectory}/hibernate.properties"
    * @since 1.0
    */
   private String hibernateProperties;
 
+  /**
+   * Path to Hibernate configuration file (.cfg.xml).
+   * Settings in this file will overwrite settings in the properties file.
+   *
+   * @parameter default-value="${project.build.outputDirectory}/hibernate.cfg.xml"
+   * @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.
+   *
+   * @since 1.1.0
+   */
+  private String persistenceUnit;
+
   /**
    * List of Hibernate-Mapping-Files (XML).
    * Multiple files can be separated with white-spaces and/or commas.
@@ -321,7 +354,7 @@ public class Hbm2DdlMojo extends AbstractMojo
   /**
    * Generate envers schema for auditing tables.
    *
-   * @parameter property="hibernate.export.envers" default-value="false"
+   * @parameter property="hibernate.export.envers" default-value="true"
    * @since 1.0.3
    */
   private boolean envers;
@@ -503,369 +536,372 @@ public class Hbm2DdlMojo extends AbstractMojo
       throw new MojoFailureException(e.getMessage());
     }
 
-    if (classes.isEmpty())
-    {
-      if (hibernateMapping == null || hibernateMapping.isEmpty())
-        throw new MojoFailureException("No annotated classes found in directory " + outputDirectory);
-    }
-    else
-    {
-      getLog().debug("Detected classes with mapping-annotations:");
-      for (Class<?> annotatedClass : classes)
-        getLog().debug("  " + annotatedClass.getName());
-    }
-
 
-    Properties properties = new Properties();
+    ValidationConfiguration config = new ValidationConfiguration();
+    // Clear unused system-properties
+    config.setProperties(new Properties());
 
-    /** Try to read configuration from properties-file */
+    ClassLoader contextClassLoader = Thread.currentThread().getContextClassLoader();
+    MavenLogAppender.startPluginLog(this);
     try
     {
-      File file = new File(hibernateProperties);
-      if (file.exists())
+      /** Try to read configuration from properties-file */
+      try
       {
-        getLog().info("Reading properties from file " + hibernateProperties + "...");
-        properties.load(new FileInputStream(file));
+        File file = new File(hibernateProperties);
+        if (file.exists())
+        {
+          getLog().info("Reading properties 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());
       }
-      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());
-    }
 
-    /** Overwrite values from properties-file or set, if given */
-    if (driverClassName != null)
-    {
-      if (properties.containsKey(DRIVER_CLASS))
-        getLog().debug(
-            "Overwriting property " +
-            DRIVER_CLASS + "=" + properties.getProperty(DRIVER_CLASS) +
-            " with the value " + driverClassName
-          );
-      else
-        getLog().debug("Using the value " + driverClassName);
-      properties.setProperty(DRIVER_CLASS, driverClassName);
-    }
-    if (url != null)
-    {
-      if (properties.containsKey(URL))
-        getLog().debug(
-            "Overwriting property " +
-            URL + "=" + properties.getProperty(URL) +
-            " with the value " + url
-          );
-      else
-        getLog().debug("Using the value " + url);
-      properties.setProperty(URL, url);
-    }
-    if (username != null)
-    {
-      if (properties.containsKey(USERNAME))
-        getLog().debug(
-            "Overwriting property " +
-            USERNAME + "=" + properties.getProperty(USERNAME) +
-            " with the value " + username
-          );
-      else
-        getLog().debug("Using the value " + username);
-      properties.setProperty(USERNAME, username);
-    }
-    if (password != null)
-    {
-      if (properties.containsKey(PASSWORD))
-        getLog().debug(
-            "Overwriting property " +
-            PASSWORD + "=" + properties.getProperty(PASSWORD) +
-            " with value " + password
-          );
-      else
-        getLog().debug("Using value " + password + " for property " + PASSWORD);
-      properties.setProperty(PASSWORD, password);
-    }
-    if (hibernateDialect != null)
-    {
-      if (properties.containsKey(DIALECT))
-        getLog().debug(
-            "Overwriting property " +
-            DIALECT + "=" + properties.getProperty(DIALECT) +
-            " with value " + hibernateDialect
-          );
-      else
-        getLog().debug(
-            "Using value " + hibernateDialect + " for property " + DIALECT
-            );
-      properties.setProperty(DIALECT, hibernateDialect);
-    }
-    if ( hibernateNamingStrategy != null )
-    {
-      if ( properties.contains(NAMING_STRATEGY))
-        getLog().debug(
-            "Overwriting property " +
-            NAMING_STRATEGY + "=" + properties.getProperty(NAMING_STRATEGY) +
-            " with value " + hibernateNamingStrategy
-           );
-      else
-        getLog().debug(
-            "Using value " + hibernateNamingStrategy + " for property " +
-            NAMING_STRATEGY
-            );
-      properties.setProperty(NAMING_STRATEGY, hibernateNamingStrategy);
-    }
+      /**
+       * Change class-loader of current thread, so that hibernate can
+       * see all dependencies!
+       */
+      Thread.currentThread().setContextClassLoader(classLoader);
 
-    /** The generated SQL varies with the dialect! */
-    if (md5s.containsKey(DIALECT))
-    {
-      String dialect = properties.getProperty(DIALECT);
-      if (md5s.get(DIALECT).equals(dialect))
-        getLog().debug("SQL-dialect unchanged.");
-      else
+      /** Try to read configuration from configuration-file */
+      try
       {
-        modified = true;
-        if (dialect == null)
+        File file = new File(hibernateConfig);
+        if (file.exists())
         {
-          getLog().debug("SQL-dialect was unset.");
-          md5s.remove(DIALECT);
+          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 (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 (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 (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 (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
         {
-          getLog().debug("SQL-dialect changed: " + dialect);
-          md5s.put(DIALECT, dialect);
+          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 = properties.getProperty(DIALECT);
-      if (dialect != null)
+      else
       {
-        modified = true;
-        md5s.put(DIALECT, properties.getProperty(DIALECT));
+        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);
+      /** 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
       {
-        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 (properties.isEmpty())
-    {
-      getLog().error("No properties set!");
-      throw new MojoFailureException("Hibernate configuration is missing!");
-    }
-
-    final Configuration config = new ValidationConfiguration(hibernateDialect);
-
-    config.setProperties(properties);
-
-    if ( properties.containsKey(NAMING_STRATEGY))
-    {
-      String namingStrategy = properties.getProperty(NAMING_STRATEGY);
-      getLog().debug("Explicitly set NamingStrategy: " + namingStrategy);
-      try
+      if (config.getProperties().isEmpty())
       {
-        @SuppressWarnings("unchecked")
-        Class<NamingStrategy> namingStrategyClass = (Class<NamingStrategy>) Class.forName(namingStrategy);
-        config.setNamingStrategy(namingStrategyClass.newInstance());
-      }
-      catch (Exception e)
-      {
-        getLog().error("Error setting NamingStrategy", e);
-        throw new MojoExecutionException(e.getMessage());
+        getLog().error("No properties set!");
+        throw new MojoFailureException("Hibernate configuration is missing!");
       }
-    }
 
-    getLog().debug("Adding annotated classes to hibernate-mapping-configuration...");
-    for (Class<?> annotatedClass : classes)
-    {
-      getLog().debug("Class " + annotatedClass);
-      config.addAnnotatedClass(annotatedClass);
-    }
+      getLog().info("Gathered hibernate-configuration (turn on debugging for details):");
+      for (Entry<Object,Object> entry : config.getProperties().entrySet())
+        getLog().info("  " + entry.getKey() + " = " + entry.getValue());
 
-    if (hibernateMapping != null)
-    {
-      try
+
+      getLog().debug("Adding explicitly configured mappings...");
+      if (hibernateMapping != null)
       {
-        MessageDigest digest = java.security.MessageDigest.getInstance("MD5");
-        for (String filename : hibernateMapping.split("[\\s,]+"))
+        try
         {
-          // First try the filename as absolute/relative path
-          File file = new File(filename);
-          if (!file.exists())
+          MessageDigest digest = java.security.MessageDigest.getInstance("MD5");
+          for (String filename : hibernateMapping.split("[\\s,]+"))
           {
-            // If the file was not found, search for it in the resource-directories
-            for (Resource resource : project.getResources())
+            // First try the filename as absolute/relative path
+            File file = new File(filename);
+            if (!file.exists())
             {
-              file = new File(resource.getDirectory() + File.separator + filename);
-              if (file.exists())
-                break;
+              // 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))
+            if (file != null && file.exists())
             {
-              getLog().debug("Found new or modified mapping-file: " + filename);
-              modified = true;
-              md5s.put(filename, newMd5);
+              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
-            {
-              getLog().debug(oldMd5 + " -> mapping-file unchanged: " + filename);
-            }
-            getLog().debug("Adding mappings from XML-configurationfile: " + file);
-            config.addFile(file);
+              throw new MojoFailureException("File " + filename + " could not be found in any of the configured resource-directories!");
           }
-          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);
       }
-      catch (NoSuchAlgorithmException e)
+
+      Target target = null;
+      try
       {
-        throw new MojoFailureException("Cannot calculate MD5 sums!", e);
+        target = Target.valueOf(this.target.toUpperCase());
       }
-      catch (FileNotFoundException e)
+      catch (IllegalArgumentException e)
       {
-        throw new MojoFailureException("Cannot calculate MD5 sums!", 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\"");
       }
-      catch (IOException e)
+      Type type = null;
+      try
       {
-        throw new MojoFailureException("Cannot calculate MD5 sums!", e);
+        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\"");
       }
-    }
 
-    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 (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;
-    }
+      Iterator<PersistentClass> it = config.getClassMappings();
+      if (!it.hasNext())
+      {
+        throw new MojoFailureException("No mapped classes found!");
+      }
+      else
+      {
+        getLog().info("Mapped classes:");
+        while (it.hasNext())
+        {
+          getLog().debug("  " + it.next().getClassName());
+        }
+      }
 
-    getLog().info("Gathered hibernate-configuration (turn on debugging for details):");
-    for (Entry<Object,Object> entry : properties.entrySet())
-      getLog().info("  " + entry.getKey() + " = " + entry.getValue());
+      if (config.getProperty(DIALECT) == null)
+        throw new MojoFailureException("hibernate-dialect must be set!");
 
-    Connection connection = null;
-    try
-    {
-      /**
-       * The connection must be established outside of hibernate, because
-       * hibernate does not use the context-classloader of the current
-       * thread and, hence, would not be able to resolve the driver-class!
-       */
-      getLog().debug("Target: " + target + ", Type: " + type);
-      switch (target)
+
+      if (target.equals(Target.SCRIPT) || target.equals(Target.NONE))
       {
-        case EXPORT:
-        case BOTH:
-          switch (type)
-          {
-            case CREATE:
-            case DROP:
-            case BOTH:
-              Class driverClass = classLoader.loadClass(properties.getProperty(DRIVER_CLASS));
-              getLog().debug("Registering JDBC-driver " + driverClass.getName());
-              DriverManager.registerDriver(new DriverProxy((Driver)driverClass.newInstance()));
-              getLog().debug(
-                  "Opening JDBC-connection to "
-                  + properties.getProperty(URL)
-                  + " as "
-                  + properties.getProperty(USERNAME)
-                  + " with password "
-                  + properties.getProperty(PASSWORD)
-                  );
-              connection = DriverManager.getConnection(
-                  properties.getProperty(URL),
-                  properties.getProperty(USERNAME),
-                  properties.getProperty(PASSWORD)
-                  );
-          }
+        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;
       }
-    }
-    catch (ClassNotFoundException e)
-    {
-      getLog().error("Dependency for driver-class " + properties.getProperty(DRIVER_CLASS) + " is missing!");
-      throw new MojoExecutionException(e.getMessage());
-    }
-    catch (Exception e)
-    {
-      getLog().error("Cannot establish connection to database!");
-      Enumeration<Driver> drivers = DriverManager.getDrivers();
-      if (!drivers.hasMoreElements())
-        getLog().error("No drivers registered!");
-      while (drivers.hasMoreElements())
-        getLog().debug("Driver: " + drivers.nextElement());
-      throw new MojoExecutionException(e.getMessage());
-    }
 
-    ClassLoader contextClassLoader = Thread.currentThread().getContextClassLoader();
-    MavenLogAppender.startPluginLog(this);
-    try
-    {
-      /**
-       * Change class-loader of current thread, so that hibernate can
-       * see all dependencies!
-       */
-      Thread.currentThread().setContextClassLoader(classLoader);
+
+      if ( config.getProperties().containsKey(NAMING_STRATEGY))
+      {
+        String namingStrategy = config.getProperty(NAMING_STRATEGY);
+        getLog().debug("Explicitly set NamingStrategy: " + namingStrategy);
+        try
+        {
+          @SuppressWarnings("unchecked")
+          Class<NamingStrategy> namingStrategyClass = (Class<NamingStrategy>) Class.forName(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());
+      StandardServiceRegistryImpl registry =
+          (StandardServiceRegistryImpl)
+          new StandardServiceRegistryBuilder()
+              .applySettings(config.getProperties())
+              .build();
 
       config.buildMappings();
 
@@ -875,7 +911,7 @@ public class Hbm2DdlMojo extends AbstractMojo
         AuditConfiguration.getFor(config);
       }
 
-      SchemaExport export = new SchemaExport(config, connection);
+      SchemaExport export = new SchemaExport(registry, config);
       export.setDelimiter(delimiter);
       export.setFormat(format);
 
@@ -916,17 +952,6 @@ public class Hbm2DdlMojo extends AbstractMojo
 
       /** Restore the old class-loader (TODO: is this really necessary?) */
       Thread.currentThread().setContextClassLoader(contextClassLoader);
-
-      /** Close the connection */
-      try
-      {
-        if (connection != null)
-          connection.close();
-      }
-      catch (SQLException e)
-      {
-        getLog().error("Error while closing connection: " + e.getMessage());
-      }
     }
 
     /** Write md5-sums for annotated classes to file */
@@ -944,6 +969,123 @@ public class Hbm2DdlMojo extends AbstractMojo
     }
   }
 
+  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!