#25 web harvest should be able to use external DB connection pool

[Piotr Dyraga]

It should be possible to integrate web harvest with some external connection pool (c3p0, dbcp, bonecp etc.)

[Piotr Dyraga]

Introduced 'jndi:database' plugin as an alternative for 'database' plugin (from 'core' namespace). Both plugins can be used in exactly the same way, except that 'jndi:database' accepts only one attribute - database hook JNDI name ('database' plugin accepts jdbc url, driver name, username and password).

'jndi:database' can be used only in the JNDI-enabled environment.

<config xmlns="http://web-harvest.sourceforge.net/schema/2.1/core"
               xmlns:jndi="http://web-harvest.sourceforge.net/schema/2.1/jndi">

  <set var="response">
    <jndi:database name="jdbc/czarny">
      select id, title, price from  products LIMIT 5;
    </jndi:database>
  </set>

</config>

Example JNDI hook:

<Resource auth="Container" description="example database" name="jdbc/czarny" 
           maxPoolSize="20" minPoolSize="5" acquireIncrement="5" driverClass="com.mysql.jdbc.Driver" 
           jdbcUrl="jdbc:mysql://localhost:3306/testdb" 
           user="myuser" password="mypassword" factory="org.apache.naming.factory.BeanFactory" type="com.mchange.v2.c3p0.ComboPooledDataSource"/>