Is there a generic way to simply take an ABI function, something like:
{
"name":"foo",
"inputs":{
"interalType":"uint256",
"name":"bar",
"type":"uint256"
},
"outputs":{
"interalType":"uint256",
"name":"baz",
"type":"uint256"
}
}
and have it encode the function signature in web3j? In web3js this seems to be incredibly simple, something like:
const eth = new Eth()
eth.abi.encodeFunctionSignature(myFunction)
Where myFunction is the section of the abi. Is there no way to do this in web3j? Or am I just missing something basic? I thought I might be able to do if I build up a Function object and then use the DefaultFunctionEncoder and then make a call to encodeFunction, but I don't see an easy way to do this on the fly. All examples I've see are using pre-built solidity contracts.
Is there a generic way to mimic what the javascript is doing?
Update:
I was able to 'mostly' do this by creating a horrible function containing a switch statement on the type and iterating through each potential type to generate a 'default version of the object. For instance return new Uint256(BigInteger.ZERO); sort of thing. It's hideous, and doesn't handle tuples (mostly because I haven't figured out how to handle those yet), but when I build my inputs that way for the function, when I encode it the value does match was web3js gives on that.
There 'has' to be a better way to handle this.
Update 2: Tuple types seem to be working now, but now I've discovered that working with byte32[] type, the signatures seem to differ from web3js and web3j. I'm having my object creator return Bytes32.DEFAULT as the Type in that case, but I'm not sure this is correct.
