How to get image URL property from Wikidata item b

问题:

I've made an android app that uses the JSON Google image search API to provide images but I have noticed that Google have stopped supporting it. I have also discovered that Wikidata sometimes provides a image property on some items, however I can't seem to get the URL location of the image using the Wikidata API.

Is there any way to get the image URL property from items in Wikidata?

回答1:

If some Wikidata item (with ID: Qxxx) has image (P18) property, you can access it by MediaWiki API:

https://www.wikidata.org/w/api.php?action=wbgetclaims&entity=Qxxx&property=P18

The response will include:

"claims": {
        "P18": [{ "mainsnak": { "datavalue": { "value": "img_name.ext" }}}]
}

where img_name.ext is the name of the image you are looking for (all whitespaces have to be replaced with _).

The final image URL will be: https://upload.wikimedia.org/wikipedia/commons/a/ab/img_name.ext, where a and b are the first and the second chars of md5sum of the img_name.ext.

For example, for item jaguar (Q35694) the API will returns image name "Junior-Jaguar-Belize-Zoo.jpg", which has md5sum: 213b31ec141dafebe457e49bcd7f9329, so a=2 and b=1, or the final image URL will be: https://upload.wikimedia.org/wikipedia/commons/2/21/Junior-Jaguar-Belize-Zoo.jpg