...  
  <!-- Add the Sonar Task -->
  <taskdef uri="antlib:org.sonar.ant" resource="org/sonar/ant/antlib.xml">
    <classpath path="path/to/sonar/ant/task/lib" /> 
    <!-- This sonar Ant task library can also be put in the ${ANT_HOME\}/lib directory-->
    <!-- In such case this classpath node is no more mandatory -->
  </taskdef>

  <!-- Out-of-the-box those parameters are optional -->
  <!-- EXAMPLE FOR MYSQL -->
  <property name="sonar.jdbc.url"
            value="jdbc:mysql://localhost:3306/sonar?useUnicode=true&amp;characterEncoding=utf8" />
  <property name="sonar.jdbc.driverClassName" value="com.mysql.jdbc.Driver" />
  <property name="sonar.jdbc.username" value="sonar" />
  <property name="sonar.jdbc.password" value="sonar" />

  <!-- SERVER ON A REMOTE HOST -->
  <property name="sonar.host.url" value="http://myserver:1234" />
...