Configure the CData JDBC Driver for NASA in a Connection Pool in Tomcat

The CData JDBC Drivers support standard JDBC interfaces to integrate with Web applications running on the JVM. This article details how to connect to NASA data from a connection pool in Tomcat.

Connect to NASA Data through a Connection Pool in Tomcat

1. Copy the CData JAR and CData .lic file to $CATALINA_HOME/lib. The CData JAR is located in the lib subfolder of the installation directory.
2. Add a definition of the resource to the context. Specify the JDBC URL here.

   Using API Key Authentication

   Most NASA API endpoints (APOD, NeoWS, DONKI, TechTransfer) require a NASA API key. Register for a free key at https://api.nasa.gov. The default DEMO_KEY provides limited access (30 requests/hour, 50 requests/day); a registered key allows 1,000 requests/hour.

   The following endpoints do not require an API key and work without authentication: EONET (Earth Observatory Natural Event Tracker), EPIC (Earth Polychromatic Imaging Camera), NASA Image and Video Library, and TechPort.

   After obtaining your API key, set the following connection properties:

   • AuthScheme: Set this to APIKey.
   • APIKey: Set this to your NASA API key. Use DEMO_KEY for limited testing.

   Example Connection String

   Profile=C:\profiles\NASA.apip;AuthScheme=APIKey;APIKey=YOUR_NASA_API_KEY
   

   Connecting to NASA

   Once the authentication is configured, you can connect to NASA and query data from any of the available tables such as AstronomyPictureOfDay, NearEarthObjectFeed, EonetEvents, and NasaImageLibrary.

   Built-in Connection String Designer

   For assistance in constructing the JDBC URL, use the connection string designer built into the NASA JDBC Driver. Either double-click the JAR file or execute the jar file from the command-line.

   java -jar cdata.jdbc.api.jar
   

   Fill in the connection properties and copy the connection string to the clipboard.

   

   You can see the JDBC URL specified in the resource definition below.

   
   <Resource name="jdbc/api"   auth="Container" type="javax.sql.DataSource" driverClassName="cdata.jdbc.api.APIDriver" factory="org.apache.tomcat.jdbc.pool.DataSourceFactory" url="jdbc:api:Profile=C:\profiles\NASA.apip;AuthScheme=APIKey;APIKey=YOUR_NASA_API_KEY" maxActive="20" maxIdle="10" maxWait="-1" />
   

   To allow a single application to access NASA data, add the code above to the context.xml in the application's META-INF directory.

   For a shared resource configuration, add the code above to the context.xml located in $CATALINA_BASE/conf. A shared resource configuration provides connectivity to NASA for all applications.

3. Add a reference to the resource to the web.xml for the application.

   
     NASA data JSP
     jdbc/API
     javax.sql.DataSource
     Container
   
   

4. Initialize connections from the connection pool:

   Context initContext = new InitialContext();
   Context envContext  = (Context)initContext.lookup("java:/comp/env");
   DataSource ds = (DataSource)envContext.lookup("jdbc/API");
   Connection conn = ds.getConnection();
     

More Tomcat Integration

The steps above show how to connect to NASA data in a simple connection pooling scenario. For more use cases and information, see the JNDI Datasource How-To in the Tomcat documentation.