Fulltext search using elastiscsearch

Hello, i would like to have an application (c++.java, python) i dont mind wich language,
where u can upload pdf files or other text files and type som “key” word, for example “apple” and the result will show you which documents contains word apple and where, using elasticsearch, sometging like this, it can be desktop app or web app 

https://medium.com/analytics-vidhya/building-a-basic-search-engine-using-elasticsearch-fscrawler-97104c1ea220