SimpleConnectionProvider

+    package de.juplo.plugins.hibernate;
+
+    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.Properties;
+    import java.util.logging.Logger;
+    import org.apache.maven.plugin.MojoFailureException;
+    import org.apache.maven.plugin.logging.Log;
+    import static org.eclipse.aether.repository.AuthenticationContext.PASSWORD;
+    import static org.eclipse.aether.repository.AuthenticationContext.USERNAME;
+    import org.hibernate.boot.registry.classloading.spi.ClassLoaderService;
+    import static org.hibernate.cfg.AvailableSettings.DRIVER;
+    import static org.hibernate.cfg.AvailableSettings.PASS;
+    import static org.hibernate.cfg.AvailableSettings.URL;
+    import static org.hibernate.cfg.AvailableSettings.USER;
+    import org.hibernate.engine.jdbc.connections.spi.ConnectionProvider;
+    import static org.hibernate.jpa.AvailableSettings.JDBC_DRIVER;
+    import static org.hibernate.jpa.AvailableSettings.JDBC_PASSWORD;
+    import static org.hibernate.jpa.AvailableSettings.JDBC_URL;
+    import static org.hibernate.jpa.AvailableSettings.JDBC_USER;
+
+    /**
+     *
+     * @author Kai Moritz
+     */
+    class SimpleConnectionProvider implements ConnectionProvider
+    {
+      private final Log log;
+
+      private Connection connection;
+
+
+      SimpleConnectionProvider(Log log)
+      {
+        this.log = log;
+      }
+
+
+      void open(ClassLoaderService classLoaderService, Properties properties)
+          throws
+            MojoFailureException
+      {
+
+        String driver = (String)
+            (properties.containsKey(DRIVER)
+                ? properties.getProperty(DRIVER)
+                : properties.getProperty(JDBC_DRIVER)
+                );
+        String url = (String)
+            (properties.containsKey(URL)
+                ? properties.getProperty(URL)
+                : properties.getProperty(JDBC_URL)
+                );
+        String user = (String)
+            (properties.containsKey(USER)
+                ? properties.getProperty(USER)
+                : properties.getProperty(JDBC_USER)
+                );
+        String password = (String)
+            (properties.containsKey(PASS)
+                ? properties.getProperty(PASS)
+                : properties.getProperty(JDBC_PASSWORD)
+                );
+
+        if (driver == null || url == null || user == null)
+        {
+          log.info("No connection opened, because connection information is incomplete");
+          log.info("Driver-Class: " + driver);
+          log.info("URL: " + url);
+          log.info("User: " + user);
+          return;
+        }
+
+        try
+        {
+          Class driverClass = classLoaderService.classForName(driver);
+
+          log.debug("Registering JDBC-driver " + driverClass.getName());
+          DriverManager
+              .registerDriver(new DriverProxy((Driver) driverClass.newInstance()));
+
+          log.debug(
+              "Opening JDBC-connection to " + properties.getProperty(URL) +
+              " as " + properties.getProperty(USERNAME) +
+              " with password " + properties.getProperty(PASSWORD)
+              );
+
+          connection = DriverManager.getConnection(url, user, password);
+        }
+        catch (Exception e)
+        {
+          throw new MojoFailureException("Could not open the JDBC-connection", e);
+        }
+      }
+
+      void close()
+      {
+        if (connection == null)
+          return;
+
+        log.debug("Closing the JDBC-connection.");
+        try
+        {
+          connection.close();
+        }
+        catch (SQLException e)
+        {
+          log.error("Error while closing the JDBC-connection: " + e.getMessage());
+        }
+      }
+
+      @Override
+      public Connection getConnection() throws SQLException
+      {
+        log.debug("Connection aquired.");
+
+        if (connection == null)
+          throw new SQLException("No connection available, because of insufficient connection information!");
+
+        return connection;
+      }
+
+      @Override
+      public void closeConnection(Connection conn) throws SQLException
+      {
+        log.debug("Connection released");
+      }
+
+      @Override
+      public boolean supportsAggressiveRelease()
+      {
+        return false;
+      }
+
+      @Override
+      public boolean isUnwrappableAs(Class unwrapType)
+      {
+        return false;
+      }
+
+      @Override
+      public <T> T unwrap(Class<T> unwrapType)
+      {
+        throw new UnsupportedOperationException("Not supported.");
+      }
+
+      /**
+       * 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);
+        }
+      }
+    }
+