How to check a bitcoin address for reality?

Question

Java

I need to use JAVA to check the bitcoin address for reality.
real is the one on which there were any transactions. The balance is not important.
Parsing and JSON is not suitable for some existing online services.

How to do this please tell me?

Answer 1

the one on which there were any transactions

a very difficult condition, for this you need to scan the blockchain.
You can do it yourself (bitcoin core cannot do this, you can make an index on transactions or control the specified list, when adding addresses, you will need to rescan the blockchain, sometimes it seems to me this is such a subtle mockery of developers) or take a ready-made client, for example btcd there is an option to create an index --addrindex and there will be a corresponding rpc request
ps if there was a requirement for a positive balance, for bitcoin core there is a UTXO list dump utility (not spent outputs) but this is a one-time operation, takes some time and prepares ( on current moment) 5 GB csv file.