1.6.0 (Dec 19, 2016)
Jun 3, 2013
Nov 24, 2021
David Ervideira (dvdme)
David Ervideira (dvdme)
Ashutosh Kumar Singh (akapribot)
Santiago Castro (bryant1410)
Sara Schertz (schertzs-amzn)
Duncan Jauncey (duncanj)
Joosep Simm (joosep-wm)
Marcos Tanaka (marcosatanaka)
Angel Muelas (Myolnir)
Martin Caslavsky (martiner)
Ashesh Singh (askmrsinh)
Source code

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A Java library for the API (previously The API is fully implemented except for callbacks. Further development will continue. A jar file with the dependencies is available under the jar/ folder for convenience. This jar file is not updated

Latest version is on maven central.

Developed with Java 1.7
There should be no trouble running this anywhere as long as there is Java support.

Maven dependency:

  • Versions 1.5.1 to 1.6.0 are on maven. Avoid using 1.5.3 and 1.5.4 because it was having issues building on graddle because of a not so well made jar file. I recommend using the latest.
  • If anyone wants to check the auto generated javadocs they are here:

Update (11-10-2016):

  • Changed api url from to

Update (16-01-2016):

  • Added proxy support

Update (12-03-2015):

  • Bug fix: No longer crashes with half hour timezones.
  • Code improvements.

Update (07-10-2014):

  • I converted the project to maven and it is now available in the repositories. I had to rename the package so now is com.github.dvdme.ForecastIOLib.
  • setUnits() and setLang() methods were simplified.
  • New getRawResponse() method to return the raw JSON response.

Update (27-09-2014):

  • Response headers that return api calls already made for a given api key and response time are read and available in a get method.
  • Javadocs slightly improved (again).

Update (26-09-2014):

  • Supported languages updated.
  • Javadocs slightly improved.
  • Flag metno-license supported.

Update (23-07-2014):

  • The language option is now supported. is available now in english, german, dutch, french, spanish and tetum. If some other is selected, english will be set. Please note that in some messages are hardcoded in english, this has nothing to do with the language option. (Also, the examples are update with the new option).

Update (15-12-2013):

  • Alerts are now supported.
  • Errors are now supported.
  • New properties in DataPoints are now supported.
  • The URL is now constructed with StringBulder().
  • Improved the internal httpGET method and it should not return truncated responses anymore. ( Suggestion by DragiPandeliev )
  • The request is now has Accept-Encoding: gzip added to the header, acording with the heartly recommendation of the documentation.
  • Improved flags class.
  • Other code improvements.

Update (29-06-2013):

  • Return null if the field is not defined rather than -1d where -1 might be an accurate value.( Contribution by matthew-cox )

Update (27-06-2013):

  • Fixed bug in timeURL in the internal url builder. ( Contribution by matthew-cox )
  • Fixed some typos in the

Update (22-06-2013):

  • Thanks to a contribution by brobzilla, ForecastIO-Lib-Java can be used with an external HTTP library. The request URL can be obtained by the getUrl method in the ForecastIO class. The ForecastIO method getForecast can now also be called with a JsonObject or with a String as parameter. Check the "Usage Examples" bellow to see how to use an external HTTP library.
  • Better error handling while using the internal HTTP method.

What is does:

  • It can read Data Points and Data blocks from the API.
    • This means it can read Currently, Minutely, Hourly and Daily data.
  • It reads all available fields.
  • It reads all the available flags except one - metno-license.
  • It reads all the available alerts.
  • It reads all the available errors.

What it does not:

  • It does not read alerts and errors (the confidence in the prediction provided by the API). Already implemented.
  • It does not implements the callback request option. Did not seamed relevant for this.

To Do:

  • Improve time zone support Kind of done.
  • Add support to errors (confidence in prediction) Done.
  • Add support to alerts Done.
  • (maybe) Add the ability to export data to CSV
  • (maybe) Add the ability of converting units of received data: (This would make sense if there were the need of displaying data in various units without having to make multiple queries.)

How it works:

The ForecastIO-Lib-Java currently has 9 classes (I'll probably add two more to deal with errors). The main class is ForecastIO: It handles the connection the gets the initial data from the API. The classes FIOCurrently, FIOMinutely, FIOHourly, FIODaily, FIOFlags and FIOAlerts contain the currently, minutely, hourly, daily, flags and alerts reports. The classes FIODataPoint, FIODataBlock handle the data in the previous reports (except for the flags). Most of the work is done by the FIODataPoint class.

Please refer to the API docs for better understanding of the data and for the API key. - You'll need a key to get it to work.

External Libraries:

  • minimal-json ForecastIO-Lib-Java uses the minimal-json for parsing the Json API response. I find this library to be great... This in not a dependency because I added the classes to my project. This is a dependency on pom.xml. Anyway there is still a file under jar/ with the dependencies.
About the package name

In case someone wonders, dme are just my initials. As there is no TLD .dme I decided to use them for the package. Because it is now available on maven, the package is com.github.dvdme.ForecastIOLib.

Usage Examples

To use it add the jar file to your project build path or add the classes from com.github.dvdme.ForecastIOLib and com.eclipse.json ( minimal-json ) or add the dependency to pom:


Data is initialized and fetched by the ForecastIO class:

ForecastIO fio = new ForecastIO(your_api_key); //instantiate the class with the API key.
fio.setUnits(ForecastIO.UNITS_SI);             //sets the units as SI - optional
fio.setExcludeURL("hourly,minutely");             //excluded the minutely and hourly reports from the reply
fio.getForecast("38.7252993", "-9.1500364");   //sets the latitude and longitude - not optional
                                               //it will fail to get forecast if it is not set
                                               //this method should be called after the options were set

...or using an external http library:

ForecastIO fio = new ForecastIO(your_api_key); //instantiate the class with the API key.
fio.setUnits(ForecastIO.UNITS_SI);             //sets the units as SI - optional
fio.setExclude("hourly,minutely");             //excluded the minutely and hourly reports from the reply
String response = Some_External_Http_Library.GET(fio.getUrl("38.7252993", "-9.1500364")); //use the getUrl method to access the
                                                                                          //generated request URL.
//Parse the reply
//Option 1, (easiest):
//Option 2

If a proxy has to be used:

ForecastIO fio = new ForecastIO(your_api_key); //instantiate the class with the API key.
fio.setHTTPProxy(proxyhostname, proxyport);    //tell, which proxy to use

If proxyhostname equals the NullPointer, no proxy will be used.

Currently, minutely, hourly, daily and flags classes are all initialized in the same way, with a ForecastIO class as an argument:

FIOMinutely minutely = new FIOMinutely(fio);

Most data is accessed like this:

currently.get().temperature(); //gets the temperature data for the currently report
daily.getDay(3).humidity();       //gets the humidity data for day 4 in the daily report

The following examples print the data available in each class.

Forecast common data:

    ForecastIO fio = new ForecastIO(your_api_key);
 fio.getForecast("38.7252993", "-9.1500364");
 System.out.println("Latitude: "+fio.getLatitude());
 System.out.println("Longitude: "+fio.getLongitude());
 System.out.println("Timezone: "+fio.getTimezone());
 System.out.println("Offset: "+fio.getOffset());

Currently report:

    FIOCurrently currently = new FIOCurrently(fio);
    //Print currently data
 String [] f  = currently.get().getFieldsArray();
 for(int i = 0; i<f.length;i++)
  System.out.println(f[i]+": "+currently.get().getByKey(f[i]));

Minutely report:

    FIOMinutely minutely = new FIOMinutely(fio);
    //In case there is no minutely data available
  System.out.println("No minutely data.");
 //Print minutely data
 for(int i = 0; i<minutely.minutes(); i++){
  String [] m = minutely.getMinute(i).getFieldsArray();
  System.out.println("Minute #"+(i+1));
  for(int j=0; j<m.length; j++)
   System.out.println(m[j]+": "+minutely.getMinute(i).getByKey(m[j]));

Hourly report:

    FIOHourly hourly = new FIOHourly(fio);
    //In case there is no hourly data available
  System.out.println("No hourly data.");
 //Print hourly data
 for(int i = 0; i<hourly.hours(); i++){
  String [] h = hourly.getHour(i).getFieldsArray();
  System.out.println("Hour #"+(i+1));
  for(int j=0; j<h.length; j++)
   System.out.println(h[j]+": "+hourly.getHour(i).getByKey(h[j]));

Daily report:

    FIODaily daily = new FIODaily(fio);
    //In case there is no daily data available
  System.out.println("No daily data.");
 //Print daily data
 for(int i = 0; i<daily.days(); i++){
  String [] h = daily.getDay(i).getFieldsArray();
  System.out.println("Day #"+(i+1));
  for(int j=0; j<h.length; j++)
   System.out.println(h[j]+": "+daily.getDay(i).getByKey(h[j]));

Flag report:

    FIOFlags flags = new FIOFlags(fio);
    //Print information for metar stations
 for(int i=0; i<flags.metarStations().length; i++)
  System.out.println("Metar Stations: "+flags.metarStations()[i]);
 //Print all available flags
 for(int i=0; i<flags.availableFlags().length; i++)

Alerts report:

    FIOAlerts alerts = new FIOAlerts(fio);
 //Check if there are alerts
 if(alerts.NumberOfAlerts() <= 0){
  System.out.println("No alerts for this location.");
 //if there are alerts, print them.
 else {
  for(int i=0; i<alerts.NumberOfAlerts(); i++)


To report issues please do it in Github or send me an email.


I generated a javadoc based in the comments I made. It is included in the files under the javadoc/ folder and here but do not expect it to be best documentation ever.


I started writing this library for two main reasons: First, I wanted to make a serious open source library that was meant to used by anyone and not just by me for quite sometime. Second, I came across the API that I found to be functional with clear and good information. Also, I like the weather and weather data and weather prediction so this is going to be very useful for me to implement my crazy ideas about weather software.


  • Thanks to everyone that contribuited to make this software better.


The code is available under the terms of the Eclipse Public License.


Thanks to JetBrains for providing an open source license for IntelliJ IDEA.