Android webj3 "insufficient funds for gas * price + value" exception

Question

I'm trying to send ether in my Android app between 2 addresses which were opened using Metamask.io There is a balance of 2 ethers in "from" account. Here the code

        Web3j web3 = Web3jFactory.build(new HttpService("https://rinkeby.infura.io/MY ACCOUNT"));


        Credentials credentials = Credentials.create(privateKeyRopsten);

        TransactionReceipt transactionReceipt = Transfer.sendFunds(
                web3, credentials, <TO ADDRESS>,
                BigDecimal.valueOf(1.0), Convert.Unit.ETHER).send();

When I run it I get

java.lang.RuntimeException: Error processing transaction request: insufficient funds for gas * price + value

Answer 1

It seems it was a problem with amount of ETHER.
When I changed Convert.Unit.ETHER to Convert.Unit.WEI it solved the problem

Answer 2

Well it seems, that your account/address (ie. account/address used in Metamask) have no sufficient amount (exactly what error message is telling you). You firstly tried to send 2 Eth, which you don't have - well you have it, but to send anything or call any smartcontract you have to pay transaction fees for that. So something more than 2 Eth. That's what "gas * price + value" part of exception message means. In second answer with Wei you are sending 1 Wei (the smallest amount of ethereum possible - see https://etherconverter.online/ or http://ethdocs.org/en/latest/ether.html).