Java Code Examples for org.web3j.abi.FunctionEncoder#encode()

private String getContractTransfer() {
    int tokenDecimals = tokensManager.getTokenByCode(tokenCode).getDecimal();
    BigInteger tokenValue = Converter.toDecimals(new BigDecimal(amountToSend), tokenDecimals).toBigInteger();
    List<Type> inputParams = new ArrayList<>();

    Type address = new Address(walletNumber);
    inputParams.add(address);

    Type value = new Uint(tokenValue);
    inputParams.add(value);

    Function function = new Function(
            "transfer",
            inputParams,
            Collections.<TypeReference<?>>emptyList());

    return FunctionEncoder.encode(function);
}
 

private String callSmartContractFunction(
        Function function, String contractAddress, NetworkInfo network, Wallet wallet) throws Exception
{
    try
    {
        String encodedFunction = FunctionEncoder.encode(function);

        org.web3j.protocol.core.methods.request.Transaction transaction
                = createEthCallTransaction(wallet.address, contractAddress, encodedFunction);
        EthCall response = getService(network.chainId).ethCall(transaction, DefaultBlockParameterName.LATEST).send();

        return response.getValue();
    }
    catch (InterruptedIOException|UnknownHostException e)
    {
        //expected to happen when user switches wallets
        return "0x";
    }
}
 

public String signContractTransaction(String contractAddress,
                                      String to,
                                      BigInteger nonce,
                                      BigInteger gasPrice,
                                      BigInteger gasLimit,
                                      BigDecimal amount,
                                      BigDecimal decimal,
                                      WalletFile walletfile,
                                      String password) throws Exception {
    BigDecimal realValue = amount.multiply(decimal);
    Function function = new Function("transfer",
            Arrays.asList(new Address(to), new Uint256(realValue.toBigInteger())),
            Collections.emptyList());
    String data = FunctionEncoder.encode(function);
    RawTransaction rawTransaction = RawTransaction.createTransaction(
            nonce,
            gasPrice,
            gasLimit,
            contractAddress,
            data);
    return signData(rawTransaction, walletfile, password);
}
 

/**
 * Call smart contract function on custom network contract. This would be used for things like ENS lookup
 * Currently because it's tied to a mainnet contract address there's no circumstance it would work
 * outside of mainnet. Users may be confused if their namespace doesn't work, even if they're currently
 * using testnet.
 *
 * @param function
 * @param contractAddress
 * @param wallet
 * @return
 */
private String callCustomNetSmartContractFunction(
        Function function, String contractAddress, Wallet wallet, int chainId)  {
    String encodedFunction = FunctionEncoder.encode(function);

    try
    {
        org.web3j.protocol.core.methods.request.Transaction transaction
                = createEthCallTransaction(wallet.address, contractAddress, encodedFunction);
        EthCall response = getService(chainId).ethCall(transaction, DefaultBlockParameterName.LATEST).send();

        return response.getValue();
    }
    catch (Exception e)
    {
        e.printStackTrace();
        return null;
    }
}
 

private String execute(
        Credentials credentials, Function function, String contractAddress) throws Exception {
    BigInteger nonce = getNonce(credentials.getAddress());

    String encodedFunction = FunctionEncoder.encode(function);

    RawTransaction rawTransaction = RawTransaction.createTransaction(
            nonce,
            GAS_PRICE,
            GAS_LIMIT,
            contractAddress,
            encodedFunction);

    byte[] signedMessage = TransactionEncoder.signMessage(rawTransaction, credentials);
    String hexValue = Numeric.toHexString(signedMessage);

    EthSendTransaction transactionResponse = web3j.ethSendRawTransaction(hexValue)
            .sendAsync().get();

    return transactionResponse.getTransactionHash();
}
 

private String callSmartContractFunction(Function function, String contractAddress)
        throws Exception {

    String encodedFunction = FunctionEncoder.encode(function);

    org.web3j.protocol.core.methods.response.EthCall response =
            web3j.ethCall(
                            Transaction.createEthCallTransaction(
                                    ALICE.getAddress(), contractAddress, encodedFunction),
                            DefaultBlockParameterName.LATEST)
                    .sendAsync()
                    .get();

    return response.getValue();
}
 

private String callSmartContractFunction(Function function, String contractAddress)
        throws Exception {
    String encodedFunction = FunctionEncoder.encode(function);

    org.web3j.protocol.core.methods.response.EthCall response =
            web3j.ethCall(
                            Transaction.createEthCallTransaction(
                                    ALICE.getAddress(), contractAddress, encodedFunction),
                            DefaultBlockParameterName.LATEST)
                    .sendAsync()
                    .get();

    return response.getValue();
}
 

private EthCall ethCall(BigInteger value) throws java.io.IOException {
    final Function function =
            new Function(
                    Revert.FUNC_SET,
                    Collections.singletonList(new Uint256(value)),
                    Collections.emptyList());
    String encodedFunction = FunctionEncoder.encode(function);

    return web3j.ethCall(
                    Transaction.createEthCallTransaction(
                            ALICE.getAddress(), contract.getContractAddress(), encodedFunction),
                    DefaultBlockParameterName.LATEST)
            .send();
}
 

/**
 * Execute constant function call - i.e. a call that does not change state of the contract
 *
 * @param function to call
 * @return {@link List} of values returned by function call
 */
private List<Type> executeCall(
        Function function) throws IOException {
    String encodedFunction = FunctionEncoder.encode(function);
    org.web3j.protocol.core.methods.response.EthCall ethCall = web3j.ethCall(
            Transaction.createEthCallTransaction(
                    transactionManager.getFromAddress(), contractAddress, encodedFunction),
            defaultBlockParameter)
            .send();

    String value = ethCall.getValue();
    return FunctionReturnDecoder.decode(value, function.getOutputParameters());
}
 

private String callSmartContractFunction(
        Function function, String contractAddress) throws Exception {
    String encodedFunction = FunctionEncoder.encode(function);
    return makeEthCall(
            org.web3j.protocol.core.methods.request.Transaction
                    .createEthCallTransaction(null, contractAddress, encodedFunction));
}
 

private String callSmartContractFunction(
        Function function, String contractAddress) throws Exception {

    String encodedFunction = FunctionEncoder.encode(function);

    org.web3j.protocol.core.methods.response.EthCall response = web3j.ethCall(
            Transaction.createEthCallTransaction(
                    ALICE.getAddress(), contractAddress, encodedFunction),
            DefaultBlockParameterName.LATEST)
            .sendAsync().get();

    return response.getValue();
}
 

private String callSmartContractFunction(
        Function function, String contractAddress) throws Exception {
    String encodedFunction = FunctionEncoder.encode(function);

    org.web3j.protocol.core.methods.response.EthCall response = web3j.ethCall(
            Transaction.createEthCallTransaction(
                    ALICE.getAddress(), contractAddress, encodedFunction),
            DefaultBlockParameterName.LATEST)
            .sendAsync().get();

    return response.getValue();
}
 

public static String getEncodedFunction(String queryName,
                                        List<Type> queryInputTypes,
                                        List<TypeReference<?>> queryOutputTypes) {

    return FunctionEncoder.encode(getFunction(queryName,
                                              queryInputTypes,
                                              queryOutputTypes));
}
 

/**
 * Execute constant function call - i.e. a call that does not change state of the contract
 *
 * @param function to call
 * @return {@link List} of values returned by function call
 */
private List<Type> executeCall(Function function) throws IOException {
    String encodedFunction = FunctionEncoder.encode(function);

    String value = call(contractAddress, encodedFunction, defaultBlockParameter);

    return FunctionReturnDecoder.decode(value, function.getOutputParameters());
}
 

private String callSmartContractFunction(Function function, String contractAddress)
        throws Exception {

    String encodedFunction = FunctionEncoder.encode(function);

    org.web3j.protocol.core.methods.response.EthCall response =
            web3j.ethCall(
                            Transaction.createEthCallTransaction(
                                    ALICE.getAddress(), contractAddress, encodedFunction),
                            DefaultBlockParameterName.LATEST)
                    .sendAsync()
                    .get();

    return response.getValue();
}
 

private String callSmartContractFunction(
        Function function, String contractAddress) throws Exception {
    String encodedFunction = FunctionEncoder.encode(function);
    return makeEthCall(
            org.web3j.protocol.core.methods.request.Transaction
                    .createEthCallTransaction(null, contractAddress, encodedFunction));
}
 

public static byte[] createTicketTransferData(String to, List<BigInteger> tokenIndices, Token token) {
    Function function = token.getTransferFunction(to, tokenIndices);

    String encodedFunction = FunctionEncoder.encode(function);
    return Numeric.hexStringToByteArray(Numeric.cleanHexPrefix(encodedFunction));
}
 

@Test
public void testEventFilter() throws Exception {
    unlockAccount();

    Function function = createFibonacciFunction();
    String encodedFunction = FunctionEncoder.encode(function);

    BigInteger gas = estimateGas(encodedFunction);
    String transactionHash = sendTransaction(ALICE, CONTRACT_ADDRESS, gas, encodedFunction);

    TransactionReceipt transactionReceipt = waitForTransactionReceipt(transactionHash);

    assertFalse(gas.equals(transactionReceipt.getGasUsed()));

    List<Log> logs = transactionReceipt.getLogs();
    assertFalse(logs.isEmpty());

    Log log = logs.get(0);

    List<String> topics = log.getTopics();
    assertEquals(topics.size(), (1));

    Event event =
            new Event(
                    "Notify",
                    Arrays.asList(
                            new TypeReference<Uint256>() {}, new TypeReference<Uint256>() {}));

    // check function signature - we only have a single topic our event signature,
    // there are no indexed parameters in this example
    String encodedEventSignature = EventEncoder.encode(event);
    assertEquals(topics.get(0), (encodedEventSignature));

    // verify our two event parameters
    List<Type> results =
            FunctionReturnDecoder.decode(log.getData(), event.getNonIndexedParameters());
    assertEquals(
            results,
            (Arrays.asList(
                    new Uint256(BigInteger.valueOf(7)), new Uint256(BigInteger.valueOf(13)))));

    // finally check it shows up in the event filter
    List<EthLog.LogResult> filterLogs =
            createFilterForEvent(encodedEventSignature, CONTRACT_ADDRESS);
    assertFalse(filterLogs.isEmpty());
}
 

public static byte[] createTrade(Token token, BigInteger expiry, List<BigInteger> ticketIndices, int v, byte[] r, byte[] s)
{
    Function function = token.getTradeFunction(expiry, ticketIndices, v, r, s);
    String encodedFunction = FunctionEncoder.encode(function);
    return Numeric.hexStringToByteArray(Numeric.cleanHexPrefix(encodedFunction));
}
 

/**
 * return an encoded function, so it can be manually signed and transmitted
 *
 * @return the function call, encoded.
 */
public String encodeFunctionCall() {
    return FunctionEncoder.encode(function);
}