[Google Sheets] Import crypto data from Coingecko

DISCLAIMER: I do not recommend investing in crypto, all tokens you will see are used as sample and not provided as financial or investment advice.

We've already seen how to add custom functions to our Google Sheets projects, importing Yahoo Finance data. Now we expand this to import cryptocurrency data from Coingecko.

I could have picked any of the million sources, but this one has a simple free plan which for light usage works well.

After registering and getting your API key, RTFM to find that they provide a lot of stuff, what we care about is the pricing data in this example, you will need to find the ID of the currency you want (NOT the token) by querying the list and then you can get the data you want by calling (add your API key at the end):

"https://api.coingecko.com/api/v3/simple/price?ids=" + token + "&vs_currencies=usd&x_cg_demo_api_key="

You can put this in a Google Sheet function as well (you can extend input parameters to get quote in different currencies as well):

function getCoingeckoData(path) {
  var result = UrlFetchApp.fetch("https://api.coingecko.com/api/v3/simple/price?ids=" + path + "&vs_currencies=usd&x_cg_demo_api_key=YOUR_API_KEY");
  var response = result.getContentText();
  var json = JSON.parse(response);
  return json[path]['usd'];
}

[Java] Get type of elements in collection using reflection

Java type erasure logic means that at runtime some information is removed/replaced from generic declarations, which poses a minor challenge when trying to identify the actual parameter types using reflection at runtime.

Here is a way:

import java.lang.reflect.Field;
import java.lang.reflect.ParameterizedType;


//maybe you are looping over fields or have a field of type Field f
ParameterizedType collectionType = (ParameterizedType) f.getGenericType();
Class<?> actualClassOfElementInCollection = (Class<?>) collectionType.getActualTypeArguments()[0];