http://blog.knutwalker.de/forecast-io-scala/

Scala wrapper library for the v2 Forecast API provided by The Dark Sky Company, LLC.

Based on https://github.com/MartinSeeler/forecast-io-wrapper

The Scala wrapper runs on top of Akka.

The Forecast API lets you query for most locations on the globe, and returns:

• Current conditions
• Minute-by-minute forecasts out to 1 hour (where available)
• Hour-by-hour forecasts out to 48 hours
• Day-by-day forecasts out to 7 days

A simple request for the current temperature:

// specify your API key
val apiKey = "replace-with-your-key"
val forecastIO = ForecastIO(apiKey)

// coordinates for Dresden, Germany
val latitude = 51.0504
val longitude = 13.7373

// For asynchronous execution
import ForecastIO.executionContext

// retrieve the current forecast
val forecast = forecastIO(latitude, longitude)

// deal with the result when it is available
forecast.foreach { result =>
  println(s"Current temperature is ${result.currently.map(_.temperature)}")
  println(s"Apparent temperature is ${result.currently.map(_.apparentTemperature)")
}

ForecastIo.apply simply returns a Future[Forecast]. Forecast and other nested POJOs are all case classes, so you can pattern match all the way through:

// specify your API key
val apiKey = "replace-with-your-key"
val forecastIO = ForecastIO(apiKey)

// coordinates for Dresden, Germany
val latitude = 51.0504
val longitude = 13.7373

// For asynchronous execution
import ForecastIO.executionContext

// retrieve the current forecast
val forecast = forecastIO(latitude, longitude)

// deal with the result when it is available
forecast onComplete {

  case Success(Forecast(_, _, timezone, _, Some(HourlyDataPoint(_, _, temperature, _, _, _, _, _)), _, _, Some(DailyDataBlock(_, _, Vector(DailyDataPoint(_, sunset), _*))))) =>

    println(s"It is $temperature degrees in $timezone and the sun sets at $sunset")
}

forecast-io-scala also tries to provide a proper Java API, similar to forecast-io-wrappers.

// specify your API key
final String apiKey = "replace-with-your-key";
final ForecastIO forecastIO = new ForecastIO(apiKey);

// coordinates for Dresden, Germany
final double latitude = 51.0504d;
final double longitude = 13.7373d;

// retrieve the current forecast
final Forecast forecast = forecastIO.getForecast(latitude, longitude);

System.out.println("Current temperature is " + forecast.getCurrently().getTemperature());
System.out.println("Apparent temperature is " + forecast.getCurrently().getApparentTemperature());

That is teh traditional blocking API. In addition to that, forecast-io-scala also provides an asynchronous API for Java

// specify your API key
final String apiKey = "replace-with-your-key";
final ForecastIO forecastIO = new ForecastIO(apiKey);

// coordinates for Dresden, Germany
final double latitude = 51.0504d;
final double longitude = 13.7373d;

// retrieve the current forecast
forecastIO.asyncForecast(latitude, longitude, new Callback<Forecast>() {
    @Override
    public void onSuccess(Forecast result) {

        System.out.println("Current temperature is " + result.getCurrently().getTemperature());
        System.out.println("Apparent temperature is " + result.getCurrently().getApparentTemperature());
    }

    @Override
    public void onFailure(Throwable t) {}
});

forecast-io-scala runs on top of Akka and thus, needs to be shutdown properly. You can do so beu calling either the static or the instance method shutdown() on ForecastIO

If omit the shutdown, your JVM will not terminate and you have to kill it abruptly.

You'll only need sbt and a JDK 7. Scala, Akka, Spray and other dependencies are downloaded during the build process.

forecast-io-scala features a fatjar, that prints some simple information about some place. You can build the jar with sbt assembly and use it like so:

java -jar -Dforecast.apikey="your-api-key-here" target/scala-2.10/forecast-io-scala-0.1.0.jar 13.37 42

Scaladoc is available at http://blog.knutwalker.de/forecast-io-scala/current/