Create a Data Access Object for NASA Data using JDBI

JDBI is a SQL convenience library for Java that exposes two different style APIs, a fluent style and a SQL object style. The CData JDBC Driver for NASA integrates connectivity to live NASA data in Java applications. By pairing these technologies, you gain simple, programmatic access to NASA data. This article explains how to build a basic Data Access Object (DAO) and the accompanying code to read NASA data.

Create a DAO for the NASA AstronomyPictureOfDay Entity

The interface below declares the desired behavior for the SQL object to create a single method for each SQL statement to be implemented.

public interface MyAstronomyPictureOfDayDAO {
  //request specific data from NASA (String type is used for simplicity)
  @SqlQuery("SELECT  FROM AstronomyPictureOfDay WHERE StartDate = :startDate")
  String findByStartDate(@Bind("startDate") String startDate);

  /*
   * close with no args is used to close the connection
   */
  void close();
}

Open a Connection to NASA

Collect the necessary connection properties and construct the appropriate JDBC URL for connecting to NASA.

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.

A connection string for NASA will typically look like the following:

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

Use the configured JDBC URL to obtain an instance of the DAO interface. The particular method shown below will open a handle bound to the instance, so the instance needs to be closed explicitly to release the handle and the bound JDBC connection.

DBI dbi = new DBI("jdbc:api:Profile=C:\profiles\NASA.apip;AuthScheme=APIKey;APIKey=YOUR_NASA_API_KEY");
MyAstronomyPictureOfDayDAO dao = dbi.open(MyAstronomyPictureOfDayDAO.class);

//do stuff with the DAO

dao.close();

Read NASA Data

With the connection open to NASA, simply call the previously defined method to retrieve data from the AstronomyPictureOfDay entity in NASA.

//disply the result of our 'find' method
String  = dao.findByStartDate("2024-01-01");
System.out.println();

Since the JDBI library is able to work with JDBC connections, you can easily produce a SQL Object API for NASA by integrating with the CData JDBC Driver for NASA. Download a free trial and work with live NASA data in custom Java applications today.