web3j - TypeReference for event with string parameter

Question

Let's say that I have the following event in my Solidity smart contract:

event Buy(address buyer, string itemName);

I am trying to construct the corresponding event in web3j Java library. This is what I have done:

public static final Event BUY = new Event(
  "Buy", Arrays.<TypeReference<?>>asList(
    new TypeReference<Address>(false) {}, // address buyer
    new TypeReference<String>(false) {}, // string itemName
  )
);  

But, it is giving me error:

Bound mismatch: The type String is not a valid substitute for the bounded parameter <T extends Type> of the type TypeReference<T>

Which type should I use instead of String?

Answer 1

Replace the String return type with Utf8String. This will resolve the issue.