如何在 Android 中使用 web3j 使用现有合同

Question

First time I am using BlockChain (using web3j) in Android, I have existing smart contract's value like BINARY and ABI details like below

    private final String BINARY = "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";
    private final String ADDRESS = "0xaA3c4b900a96520e44444669350bf5302b90EbD9";
    private final String URL = "http://10.12.13.223:8545";
    private final String ABI = "[{\"constant\":false,\"inputs\":[{\"internalType\":\"address\",\"name\":\"owner\",\"type\":\"address\"},{\"internalType\":\"bytes32\",\"name\":\"claimid\",\"type\":\"bytes32\"},{\"internalType\":\"bytes32\",\"name\":\"claimhash\",\"type\":\"bytes32\"}],\"name\":\"addClaim\",\"outputs\":[],\"payable\":false,\"stateMutability\":\"nonpayable\",\"type\":\"function\"},{\"constant\":false,\"inputs\":[{\"internalType\":\"address\",\"name\":\"issuer\",\"type\":\"address\"},{\"internalType\":\"address\",\"name\":\"owner\",\"type\":\"address\"},{\"internalType\":\"bytes32\",\"name\":\"claimid\",\"type\":\"bytes32\"}],\"name\":\"removeClaim\",\"outputs\":[],\"payable\":false,\"stateMutability\":\"nonpayable\",\"type\":\"function\"},{\"constant\":true,\"inputs\":[{\"internalType\":\"address\",\"name\":\"issuer\",\"type\":\"address\"},{\"internalType\":\"address\",\"name\":\"owner\",\"type\":\"address\"},{\"internalType\":\"bytes32\",\"name\":\"claimid\",\"type\":\"bytes32\"}],\"name\":\"getClaim\",\"outputs\":[{\"internalType\":\"bytes32\",\"name\":\"\",\"type\":\"bytes32\"}],\"payable\":false,\"stateMutability\":\"view\",\"type\":\"function\"},{\"anonymous\":false,\"inputs\":[{\"indexed\":true,\"internalType\":\"address\",\"name\":\"sender\",\"type\":\"address\"},{\"indexed\":true,\"internalType\":\"address\",\"name\":\"owner\",\"type\":\"address\"},{\"indexed\":true,\"internalType\":\"bytes32\",\"name\":\"claimid\",\"type\":\"bytes32\"},{\"indexed\":false,\"internalType\":\"bytes32\",\"name\":\"claimhash\",\"type\":\"bytes32\"}],\"name\":\"ClaimAdded\",\"type\":\"event\"},{\"anonymous\":false,\"inputs\":[{\"indexed\":true,\"internalType\":\"address\",\"name\":\"sender\",\"type\":\"address\"},{\"indexed\":true,\"internalType\":\"address\",\"name\":\"owner\",\"type\":\"address\"},{\"indexed\":true,\"internalType\":\"bytes32\",\"name\":\"claimid\",\"type\":\"bytes32\"}],\"name\":\"ClaimRemoved\",\"type\":\"event\"}]";

Now as per document " If I have already the contract's binary and ABI, then I don't need to use web3j to generate it. Just get those values and create the classes "

I have already those values, but I don't know, how to use?

Like I just need to create class for ex.

class MyContract {
    private final String BINARY = "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";
    private final String ADDRESS = "0xaA3c4b900a96520e44444669350bf5302b90EbD9";
    private final String URL = "http://10.12.13.223:8545";
    private final String ABI = "[{\"constant\":false,\"inputs\":[{\"internalType\":\"address\",\"name\":\"owner\",\"type\":\"address\"},{\"internalType\":\"bytes32\",\"name\":\"claimid\",\"type\":\"bytes32\"},{\"internalType\":\"bytes32\",\"name\":\"claimhash\",\"type\":\"bytes32\"}],\"name\":\"addClaim\",\"outputs\":[],\"payable\":false,\"stateMutability\":\"nonpayable\",\"type\":\"function\"},{\"constant\":false,\"inputs\":[{\"internalType\":\"address\",\"name\":\"issuer\",\"type\":\"address\"},{\"internalType\":\"address\",\"name\":\"owner\",\"type\":\"address\"},{\"internalType\":\"bytes32\",\"name\":\"claimid\",\"type\":\"bytes32\"}],\"name\":\"removeClaim\",\"outputs\":[],\"payable\":false,\"stateMutability\":\"nonpayable\",\"type\":\"function\"},{\"constant\":true,\"inputs\":[{\"internalType\":\"address\",\"name\":\"issuer\",\"type\":\"address\"},{\"internalType\":\"address\",\"name\":\"owner\",\"type\":\"address\"},{\"internalType\":\"bytes32\",\"name\":\"claimid\",\"type\":\"bytes32\"}],\"name\":\"getClaim\",\"outputs\":[{\"internalType\":\"bytes32\",\"name\":\"\",\"type\":\"bytes32\"}],\"payable\":false,\"stateMutability\":\"view\",\"type\":\"function\"},{\"anonymous\":false,\"inputs\":[{\"indexed\":true,\"internalType\":\"address\",\"name\":\"sender\",\"type\":\"address\"},{\"indexed\":true,\"internalType\":\"address\",\"name\":\"owner\",\"type\":\"address\"},{\"indexed\":true,\"internalType\":\"bytes32\",\"name\":\"claimid\",\"type\":\"bytes32\"},{\"indexed\":false,\"internalType\":\"bytes32\",\"name\":\"claimhash\",\"type\":\"bytes32\"}],\"name\":\"ClaimAdded\",\"type\":\"event\"},{\"anonymous\":false,\"inputs\":[{\"indexed\":true,\"internalType\":\"address\",\"name\":\"sender\",\"type\":\"address\"},{\"indexed\":true,\"internalType\":\"address\",\"name\":\"owner\",\"type\":\"address\"},{\"indexed\":true,\"internalType\":\"bytes32\",\"name\":\"claimid\",\"type\":\"bytes32\"}],\"name\":\"ClaimRemoved\",\"type\":\"event\"}]";
}

Now how can I use this class for read or write value from Contract?

Answer 1

By trial and error, I found a solution. If I have an existing ABI and BINARY then it needs to be in two files:

for example

MyContract.abi -> In this file, I will paste ABI code
MyContract.bin -> In this file, I will paste BINARY code.

Then I will execute below command to generate the contract wrapper.

web3j solidity generate -b /path/to/<smart-contract>.bin -a /path/to/<smart-contract>.abi -o /path/to/src/main/java -p com.your.organisation.name