Chapter 352. Yahoo Query Language Component
Available as of Camel version 2.21
The yql component is used for accessing the Yahoo Query Language platform.
The YQL (Yahoo! Query Language) platform enables you to query, filter, and combine data across the web through a single interface. It exposes a SQL-like syntax that is both familiar to developers and expressive enough for getting the right data.
Maven users will need to add the following dependency to their pom.xml for this component:
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-yql</artifactId>
<version>x.x.x</version>
<!-- use the same version as your Camel core version -->
</dependency>352.1. URI format
yql://query[?options]
Where query represents the YQL query.
352.2. Options
The Yahoo Query Language component supports 2 options which are listed below.
| Name | Description | Default | Type |
|---|---|---|---|
| connectionManager (producer) | To use a custom configured HttpClientConnectionManager. | HttpClientConnection Manager | |
| 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 Yahoo Query Language endpoint is configured using URI syntax:
yql:query
with the following path and query parameters:
352.2.1. Path Parameters (1 parameters):
| Name | Description | Default | Type |
|---|---|---|---|
| query | Required The YQL statement to execute. | String |
352.2.2. Query Parameters (10 parameters):
| Name | Description | Default | Type |
|---|---|---|---|
| callback (producer) | The name of the JavaScript callback function for JSONP format. If callback is set and if format=json, then the response format is JSON. For more information on using XML instead of JSON, see JSONP-X. https://developer.yahoo.com/yql/guide/response.html | String | |
| crossProduct (producer) | When given the value optimized, the projected fields in SELECT statements that may be returned in separate item elements in the response are optimized to be in a single item element instead. The only allowed value is optimized. More information https://developer.yahoo.com/yql/guide/response.htmlresponse-optimizing= | String | |
| debug (producer) | If true, and if diagnostic is set to true, debug data is returned with the response. More information: https://developer.yahoo.com/yql/guide/dev-external_tables.htmlodt-enable-logging= | false | boolean |
| diagnostics (producer) | If true, diagnostic information is returned with the response. | false | boolean |
| env (producer) | Allows you to use multiple Open Data Tables through a YQL environment file. More information https://developer.yahoo.com/yql/guide/yql_storage.htmlusing-records-env-files= | String | |
| format (producer) | The expected format. Allowed values: xml or json. | json | String |
| jsonCompat (producer) | Enables lossless JSON processing. The only allowed value is new. More information https://developer.yahoo.com/yql/guide/response.htmljson-to-json | String | |
| throwExceptionOnFailure (producer) | Option to disable throwing the YqlHttpException in case of failed responses from the remote server. This allows you to get all responses regardless of the HTTP status code. | true | boolean |
| synchronous (advanced) | Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported). | false | boolean |
| https (security) | Option to use HTTPS to communicate with YQL. | true | boolean |
352.3. Exchange data format
Camel will deliver the body as a JSON or XML formatted java.lang.String (see the format option above).
352.4. Message Headers
| Header | Description |
|---|---|
|
| Original HTTP request sent to YQL. |
|
| Status code from the response. |
352.5. Samples
352.5.1. Sample 1
In this example we query YQL to obtain the current wind and atmosphere data in Chicago:
from("direct:start")
.to("yql://select wind, atmosphere from weather.forecast where woeid in (select woeid from geo.places(1) where text='chicago, il'");Which will setup the body as:
{
"query":{
"count":1,
"created":"2017-11-01T19:37:26Z",
"lang":"en-US",
"results":{
"channel":{
"wind":{
"chill":"32",
"direction":"165",
"speed":"22"
},
"atmosphere":{
"humidity":"71",
"pressure":"994.0",
"rising":"0",
"visibility":"16.1"
}
}
}
}
}and the headers:
| Header | Value |
|---|---|
|
| |
|
| 200 |
352.5.2. Sample 2
In this example we query YQL to obtain the Google quote.
from("direct:start")
.to("yql://select symbol, Ask, Bid, AverageDailyVolume from yahoo.finance.quotes where symbol in ('GOOG')?env=store://datatables.org/alltableswithkeys&https=false&callback=yqlCallback");Which will setup the body as:
/**/yqlCallback({
"query":{
"count":1,
"created":"2017-11-01T19:48:17Z",
"lang":"en-US",
"results":{
"quote":{
"symbol":"GOOG",
"Bid":"1025.57",
"Ask":"1025.92",
"AverageDailyVolume":"1350640"AverageDailyVolume
}
}
}
});and the headers:
| Header | Value |
|---|---|
|
| |
|
| 200 |
352.5.3. Sample 3
In this example we query YQL to obtain one book written by Barack Obama
from("direct:start")
.to("yql://select * from google.books where q='barack obama' and maxResults=1?format=xml&crossProduct=optimized&env=store://datatables.org/alltableswithkeys");Which will setup the body as:
<?xml version="1.0" encoding="UTF-8"?>
<query xmlns:yahoo="http://www.yahooapis.com/v1/base.rng" yahoo:count="1" yahoo:created="2017-11-01T20:32:22Z" yahoo:lang="en-US">
<results>
<json>
<kind>books#volumes</kind>
<totalItems>1993</totalItems>
<items>
<kind>books#volume</kind>
<id>HRCHJp-V0QUC</id>
<etag>SeTJeSgFDzo</etag>
<selfLink>https://www.googleapis.com/books/v1/volumes/HRCHJp-V0QUC</selfLink>
<volumeInfo>
<title>Dreams from My Father</title>
<subtitle>A Story of Race and Inheritance</subtitle>
<authors>Barack Obama</authors>
<publisher>Broadway Books</publisher>
<publishedDate>2007-01-09</publishedDate>
...
</volumeInfo>
</items>
</json>
</results>
</query>
<!-- total: 646 -->and the headers:
| Header | Value |
|---|---|
|
| |
|
| 200 |
