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h2. Weather Component

The *weather:* component is used for polling weather information from [Open Weather Map|http://openweathermap.org] - a site that provides free global weather and forecast information. The information is returned as a json String object.

Camel will poll for updates to the current weather and forecasts once per hour by default.

Maven users will need to add the following dependency to their {{pom.xml}} for this component:
{code:xml}
<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-weather</artifactId>
    <version>x.x.x</version>
    <!-- use the same version as your Camel core version -->
</dependency>
{code}

h3. URI format

{code}
weather://<unused name>[?options]
{code}


h3. Options
{div:class=confluenceTableSmall}
|| Property || Default || Description ||
| {{location}} | {{null}} |  If null Camel will try and determine your current location using the geolocation of your ip address, else specify the city,country. For well known city names, Open Weather Map will determine the best fit, but multiple results may be returned. Hence specifying and country as well will return more accurate data. If you specify "current" as the location then the component will try to get the current latitude and longitude and use that to get the weather details. |
| {{period}} | {{null}} | If null, the current weather will be returned, else use values of 5, 7, 14 days. Only the numeric value for the forecast period is actually parsed, so spelling, capitalisation of the time period is up to you (its ignored) | 
| {{mode}} | {{JSON}} | The output format of the weather data. The possible values are {{HTML}}, {{JSON}} or {{XML}} | 
| {{units}} | {{METRIC}} | The units for temperature measurement. The possible values are {{IMPERIAL}} or {{METRIC}} | 
| {{consumer.delay}} | {{3600000}} | Delay in millis between each poll (default is 1 hour) |
| {{consumer.initialDelay}} | {{1000}} | Millis before polling starts. |
| {{consumer.userFixedDelay}} | {{false}} | If {{true}}, use fixed delay between polls, otherwise fixed rate is used. See [ScheduledExecutorService|http://java.sun.com/j2se/1.5.0/docs/api/java/util/concurrent/ScheduledExecutorService.html] in JDK for details. |
{div}

You can append query options to the URI in the following format, {{?option=value&option=value&...}}

h3. Exchange data format

Camel will deliver the body as a json formatted java.lang.String (see the {{mode}} option above).


h3. Message Headers
{div:class=confluenceTableSmall}
|| Header || Description ||
| {{CamelWeatherQuery}} | The original query URL sent to the Open Weather Map site |
| {{CamelWeatherLocation}} | Used by the producer to override the endpoint location and use the location from this header instead. |
{div}

h3. Samples
In this sample we find the 7 day weather forecast for Madrid, Spain:

{code}
from("weather:foo?location=Madrid,Spain&period=7 days").to("jms:queue:weather");
{code}

To just find the current weather for your current location you can use this:
{code}
from("weather:foo").to("jms:queue:weather");
{code}

And to find the weather using the producer we do:
{code}
from("direct:start")
  .to("weather:foo?location=Madrid,Spain");
{code}

And we can send in a message with a header to get the weather for any location as shown:
{code}
  String json = template.requestBodyAndHeader("direct:start", "", "CamelWeatherLocation", "Paris,France", String.class);
{code}

And to get the weather at the current location, then:
{code}
  String json = template.requestBodyAndHeader("direct:start", "", "CamelWeatherLocation", "current", String.class);
{code}