Chapter 339. Weather Component

Available as of Camel version 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. It can also be used to query the weather api based on the parameters defined on the endpoint which is used as producer.

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>

339.1. URI format

weather://<unused name>[?options]

339.2. REMARK

Since the 9th of October, an Api Key is required to access the openweather service. This key is passed as parameter to the URI definition of the weather endpoint using the appid param !

339.3. Geolocation provider

Since July 2018 FreegeoIP is no longer available. The camel-weather component was using this API. We switch to IPstack so you’ll need to specify and Access Key and the IP from where you’re using the API now on.

339.4. Options

The Weather component supports 3 options, which are listed below.

NameDescriptionDefaultType

geolocationAccessKey (common)

The geolocation service now needs an accessKey to be used

 

String

geolocationRequestHost IP (common)

The geolocation service now needs to specify the IP associated to the accessKey you’re using

 

String

resolveProperty Placeholders (advanced)

Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders.

true

boolean

The Weather endpoint is configured using URI syntax:

weather:name

with the following path and query parameters:

339.4.1. Path Parameters (1 parameters):

NameDescriptionDefaultType

name

Required The name value is not used.

 

String

339.4.2. Query Parameters (45 parameters):

NameDescriptionDefaultType

appid (common)

Required APPID ID used to authenticate the user connected to the API Server

 

String

headerName (common)

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.

 

String

language (common)

Language of the response.

en

WeatherLanguage

mode (common)

The output format of the weather data.

JSON

WeatherMode

period (common)

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)

 

String

units (common)

The units for temperature measurement.

 

WeatherUnits

weatherApi (common)

The API to be use (current, forecast/3 hour, forecast daily, station)

 

WeatherApi

bridgeErrorHandler (consumer)

Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored.

false

boolean

sendEmptyMessageWhenIdle (consumer)

If the polling consumer did not poll any files, you can enable this option to send an empty message (no body) instead.

false

boolean

exceptionHandler (consumer)

To let the consumer use a custom ExceptionHandler. Notice if the option bridgeErrorHandler is enabled then this options is not in use. By default the consumer will deal with exceptions, that will be logged at WARN or ERROR level and ignored.

 

ExceptionHandler

exchangePattern (consumer)

Sets the exchange pattern when the consumer creates an exchange.

 

ExchangePattern

pollStrategy (consumer)

A pluggable org.apache.camel.PollingConsumerPollingStrategy allowing you to provide your custom implementation to control error handling usually occurred during the poll operation before an Exchange have been created and being routed in Camel.

 

PollingConsumerPoll Strategy

httpConnectionManager (advanced)

To use a custom HttpConnectionManager to manage connections

 

HttpConnectionManager

synchronous (advanced)

Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported).

false

boolean

backoffErrorThreshold (scheduler)

The number of subsequent error polls (failed due some error) that should happen before the backoffMultipler should kick-in.

 

int

backoffIdleThreshold (scheduler)

The number of subsequent idle polls that should happen before the backoffMultipler should kick-in.

 

int

backoffMultiplier (scheduler)

To let the scheduled polling consumer backoff if there has been a number of subsequent idles/errors in a row. The multiplier is then the number of polls that will be skipped before the next actual attempt is happening again. When this option is in use then backoffIdleThreshold and/or backoffErrorThreshold must also be configured.

 

int

delay (scheduler)

Milliseconds before the next poll. You can also specify time values using units, such as 60s (60 seconds), 5m30s (5 minutes and 30 seconds), and 1h (1 hour).

500

long

greedy (scheduler)

If greedy is enabled, then the ScheduledPollConsumer will run immediately again, if the previous run polled 1 or more messages.

false

boolean

initialDelay (scheduler)

Milliseconds before the first poll starts. You can also specify time values using units, such as 60s (60 seconds), 5m30s (5 minutes and 30 seconds), and 1h (1 hour).

1000

long

runLoggingLevel (scheduler)

The consumer logs a start/complete log line when it polls. This option allows you to configure the logging level for that.

TRACE

LoggingLevel

scheduledExecutorService (scheduler)

Allows for configuring a custom/shared thread pool to use for the consumer. By default each consumer has its own single threaded thread pool.

 

ScheduledExecutor Service

scheduler (scheduler)

To use a cron scheduler from either camel-spring or camel-quartz2 component

none

ScheduledPollConsumer Scheduler

schedulerProperties (scheduler)

To configure additional properties when using a custom scheduler or any of the Quartz2, Spring based scheduler.

 

Map

startScheduler (scheduler)

Whether the scheduler should be auto started.

true

boolean

timeUnit (scheduler)

Time unit for initialDelay and delay options.

MILLISECONDS

TimeUnit

useFixedDelay (scheduler)

Controls if fixed delay or fixed rate is used. See ScheduledExecutorService in JDK for details.

true

boolean

cnt (filter)

Number of results to be found

 

Integer

ids (filter)

List of id’s of city/stations. You can separate multiple ids by comma.

 

String

lat (filter)

Latitude of location. You can use lat and lon options instead of location. For boxed queries this is the bottom latitude.

 

String

location (filter)

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.

 

String

lon (filter)

Longitude of location. You can use lat and lon options instead of location. For boxed queries this is the left longtitude.

 

String

rightLon (filter)

For boxed queries this is the right longtitude. Needs to be used in combination with topLat and zoom.

 

String

topLat (filter)

For boxed queries this is the top latitude. Needs to be used in combination with rightLon and zoom.

 

String

zip (filter)

Zip-code, e.g. 94040,us

 

String

zoom (filter)

For boxed queries this is the zoom. Needs to be used in combination with rightLon and topLat.

 

Integer

proxyAuthDomain (proxy)

Domain for proxy NTLM authentication

 

String

proxyAuthHost (proxy)

Optional host for proxy NTLM authentication

 

String

proxyAuthMethod (proxy)

Authentication method for proxy, either as Basic, Digest or NTLM.

 

String

proxyAuthPassword (proxy)

Password for proxy authentication

 

String

proxyAuthUsername (proxy)

Username for proxy authentication

 

String

proxyHost (proxy)

The proxy host name

 

String

proxyPort (proxy)

The proxy port number

 

Integer

geolocationAccessKey (security)

Required The geolocation service now needs an accessKey to be used

 

String

geolocationRequestHostIP (security)

Required The geolocation service now needs to specify the IP associated to the accessKey you’re using

 

String

You can append query options to the URI in the following format, ?option=value&option=value&…​

339.5. Exchange data format

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

339.6. Message Headers

HeaderDescription

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.

339.7. Samples

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

from("weather:foo?location=Madrid,Spain&period=7 days&appid=APIKEY&geolocationAccessKey=IPSTACK_ACCESS_KEY&geolocationRequestHostIP=LOCAL_IP").to("jms:queue:weather");

To just find the current weather for your current location you can use this:

from("weather:foo?appid=APIKEY&geolocationAccessKey=IPSTACK_ACCESS_KEY&geolocationRequestHostIP=LOCAL_IP").to("jms:queue:weather");

And to find the weather using the producer we do:

from("direct:start")
  .to("weather:foo?location=Madrid,Spain&appid=APIKEY&geolocationAccessKey=IPSTACK_ACCESS_KEY&geolocationRequestHostIP=LOCAL_IP");

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&appid=APIKEY", String.class);

And to get the weather at the current location, then:

  String json = template.requestBodyAndHeader("direct:start", "", "CamelWeatherLocation", "current&appid=APIKEY", String.class);