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&property=P18&entity=Qxxx
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
回答2:
Took me a while to figure this one out. The hash sum that is being talked about is not the value at P18[0].mainsnak.hash.
You need to hashsum("Junior-Jaguar-Belize-Zoo.jpg"). The string that is the name, (after replacing whitespaces with "_". That will give you the 213B31EC141DAFEBE457E49BCD7F9329 hash sum which you can use to determine the url.
来源：https://stackoverflow.com/questions/34393884/how-to-get-image-url-property-from-wikidata-item-by-api