Configuring GDAS with a JDBC Connection

Below is an example of a <dataset_config> element configured to use the JDBC software.

  <dataset_config DatasetName="BC_forest_cover" 
                                   DatasetDomain="nfis.org">
    <parameter name="table_name" value="FIP_LAYER"/>            
    <parameter name="connParams" value="username=myUserName, 
          password=secretPassword, 
          conn_url=jdbc:oracle:thin:@db.nfis.org:1521:myDatabase, 
          jdbc_driver=oracle.jdbc.driver.OracleDriver"/>
    <geo_linkage_field_type value="string"/>
    <data_retriever_class data_retriever_class_name=
                "org.nfis.gdas.v091.JDBCDataRetriever"/>
  </dataset_config>

How to complete the JDBC <dataset_config> <parameter elements>

There are two <parameter> elements that are part of the JDBC configuration.

1. Table Name <parameter>

   One parameter element's attribute 'name' must have the value "table_name". The elements 'value' attribute has the name of the table that is to be queried or the name of the *.dbf file. Example:

   <parameter name="table_name" value="FIP_LAYER"/>

2. Connection <parameter>

   This parameter element defines what type of a connection is being used, single connection or connection pool. The 'name' attribute must have the value "connParams" when using a single connection or "connectionPoolParams" when connection pooling is used. This element has as its 'value' a comma delimited string which defines the connection parameters.

   • connParams

     If the parameter elements 'name' attribute's value is "connParams" this means you will be making a direct connection to the database. The comma delimited string of the 'value' attribute must contain the following key=value pairs:

     • username=loginName (Not required for .dbf files),

     • password=myPassword (Not required for .dbf files),
     • jdbc_url=connect string for the JDBC data source,

       *.dbf example: conn_url=jdbc:DBF:////data

       Oracle example: conn_url=jdbc:oracle:thin:@db.nfis.org:1521:myDatabase,

     • conn_driver=JDBC driver used to connect to data source

       Different data sources are accessed using specific JDBC drivers. The Oracle driver we use is: oracle.jdbc.driver.OracleDriver.

       Drivers included in this installation are:

       • OracleDriver: oracle.jdbc.driver.OracleDriver

         Oracle Driver Documentation

       • DBF Driver: com.hxtt.sql.dbf.DBFDriver

         DBF Driver Documentation

       If you need another driver, it must be put in the classpath for the application (for tomcat this is the TOMCAT_HOME/common/lib or the projects WEB-INF/lib directory) and its Java class name used as the value for the conn_driver key.

   • connectionPoolParams

     If the parameter element's 'name' attribute's value is 'connectionPoolParams' this means GDAS will look for a connection pool configured in the web container. The comma delimited string of the 'value' attribute must contain the following key=value pairs:

     • pool_name=name of the connection pool as configured in the J2EE web server (Tomcat),
     • naming_context=the context to look into for the pool_name connection pool as configured in the J2EE web server (Tomcat)

Values for the <geo_linkage_field_type> element

This field describes the datatype of the returned attribute and must be one of three values:

1. string
2. number
3. float

Values for the <data_retriever_class> element

For all JDBC connections the value for this element's data_retriever_class_name attribute is:

org.nfis.gdas.v091.JDBCDataRetriever