Create a Data Access Object for OpenWeatherMap 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 OpenWeatherMap integrates connectivity to live OpenWeatherMap data in Java applications. By pairing these technologies, you gain simple, programmatic access to OpenWeatherMap data. This article explains how to build a basic Data Access Object (DAO) and the accompanying code to read OpenWeatherMap data.

Create a DAO for the OpenWeatherMap AccumulatedPrecipitation 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 MyAccumulatedPrecipitationDAO {
  //request specific data from OpenWeatherMap (String type is used for simplicity)
  @SqlQuery("SELECT  FROM AccumulatedPrecipitation WHERE Latitude = :latitude")
  String findByLatitude(@Bind("latitude") String latitude);

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

Open a Connection to OpenWeatherMap

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

Using API Key Authentication

To obtain an API key, sign up for a free account at https://openweathermap.org/api and navigate to the API keys section of your dashboard. Copy your API key for use in the connection configuration.

After setting the following connection properties, you are ready to connect:

• AuthScheme: Set this to APIKey.
• APIKey: Set this to your OpenWeatherMap API key.

Built-in Connection String Designer

For assistance in constructing the JDBC URL, use the connection string designer built into the OpenWeatherMap 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 OpenWeatherMap will typically look like the following:

jdbc:api:Profile=C:\path\to\OpenWeatherMap.apip;AuthScheme=APIKey;ProfileSettings="APIKey=your_openweathermap_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:\path\to\OpenWeatherMap.apip;AuthScheme=APIKey;ProfileSettings="APIKey=your_openweathermap_api_key";");
MyAccumulatedPrecipitationDAO dao = dbi.open(MyAccumulatedPrecipitationDAO.class);

//do stuff with the DAO

dao.close();

Read OpenWeatherMap Data

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

//disply the result of our 'find' method
String  = dao.findByLatitude("40.7128");
System.out.println();

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