Chapter 158. Weather
Weather Component
Available as of Camel 2.12
The weather: component is used for polling weather information from Open Weather Map - 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:
<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>
URI format
weather://<unused name>[?options]
Options
| 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. You can use lat and lon options instead of location. |
lat
|
null
|
Latitude of location. You can use lat and lon options instead of location. |
lon
|
null
|
Longitude of location. You can use lat and lon options instead of location. |
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) |
headerName
|
null
|
To store the weather result in this header instead of the message body. This is useable if you want to keep current message body as-is. |
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 in JDK for details.
|
You can append query options to the URI in the following format,
?option=value&option=value&...
Exchange data format
Camel will deliver the body as a json formatted java.lang.String (see the
mode option above).
Message Headers
| 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. |
Samples
In this sample we find the 7 day weather forecast for Madrid, Spain:
from("weather:foo?location=Madrid,Spain&period=7 days").to("jms:queue:weather");
To just find the current weather for your current location you can use this:
from("weather:foo").to("jms:queue:weather");
And to find the weather using the producer we do:
from("direct:start")
.to("weather:foo?location=Madrid,Spain");
And we can send in a message with a header to get the weather for any location as shown:
String json = template.requestBodyAndHeader("direct:start", "", "CamelWeatherLocation", "Paris,France", String.class);
And to get the weather at the current location, then:
String json = template.requestBodyAndHeader("direct:start", "", "CamelWeatherLocation", "current", String.class);
