Hello Roberto
try this:
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>hibernate3-maven-plugin</artifactId>
<configuration>
<components>
<component>
<name>hbm2ddl</name>
<outputDirectory>res/db</outputDirectory>
</component>
</components>
<componentProperties>
<configurationfile>/res/db/hibernate.cfg.xml</configurationfile>
<propertyfile>/res/db/hsqldb.properties</propertyfile>
<outputfilename>hsqldb-schema.sql</outputfilename>
<export>false</export>
<jdk5>true</jdk5>
<format>true</format>
</componentProperties>
</configuration>
<executions>
<execution>
<phase>generate-test-resources</phase>
<id>hsqldb-schema.sql</id>
<goals>
<goal>hbm2ddl</goal>
</goals>
</execution>
</executions>
<dependencies>
<dependency>
<groupId>hsqldb</groupId>
<artifactId>hsqldb</artifactId>
<version>1.8.0.7</version>
</dependency>
</dependencies>
</plugin>
Regards
Johann Reyes