Use the calldata returned by okxswapapi and combine it with your library to implement the token exchange problem

[dengxinrong]

private static final RpcClient client = new RpcClient(Cluster.MAINNET);
private static Account signer = new Account(Base58.decode(SOLANA_SECRET_KEY));

public static void main(String[] args) {
    try {
        // Retrieve the block hash
        String recentBlockHash = client.getApi().getLatestBlockhash().getValue().getBlockhash();
        if (recentBlockHash == null || recentBlockHash.isEmpty()) {
            throw new RuntimeException("Failed to fetch recent block hash");
        }

        // Specify the amount to swap (in wSOL)
        BigDecimal desiredAmount = new BigDecimal("0.2"); // Amount of wSOL to buy
        int wsolPrecision = 9; // wSOL precision
        BigDecimal adjustedAmount = adjustForPrecision(desiredAmount, wsolPrecision);

        // Prepare the parameters for the swap
        Map<String, String> swapParams = new HashMap<>();
        swapParams.put("chainId", chainId);
        swapParams.put("fromTokenAddress", FROM_TOKEN_ADDRESS);
        swapParams.put("toTokenAddress", TO_TOKEN_ADDRESS);
        swapParams.put("amount", adjustedAmount.toPlainString());
        swapParams.put("slippage", SLIPPAGE.toString());
        swapParams.put("userWalletAddress", "");

        // Get swap data from OKX
        JSONObject swapResponse = getSwapData(swapParams);

        System.out.println("OKX Swap Data: " + swapResponse);

        // Extract transaction data (assuming it's base58 encoded)
        String transactionData = swapResponse.getJSONArray("data").getJSONObject(0).getJSONObject("tx").getString("data");
        byte[] data = Base58.decode(transactionData); // Decode the tx data

        // Create the transaction instruction
        PublicKey programId = new PublicKey("6m2CDdhRgxpH4WjvdzxAYbGxwdGUz5MziiL5jek2kBma"); // DEX program ID
        List<AccountMeta> keys = Arrays.asList(
                new AccountMeta(signer.getPublicKey(), true, true) // Signer account
        );

        TransactionInstruction instruction = new TransactionInstruction(programId, keys, data);

        // Create the transaction
        Transaction transaction = new Transaction();
        transaction.addInstruction(instruction);
        transaction.setRecentBlockHash(recentBlockHash);

        // Sign the transaction
       // transaction.sign(signer);

        // Send the transaction
        String txid = client.getApi().sendTransaction(transaction, signer);

        System.out.println("Transaction ID: " + txid);

    } catch (Exception e) {
        e.printStackTrace();
    }
}

Transaction ID: Ztmi9PgirAM29NcfW3GPzEuAjv1ZLfDD1HtZoNEfmo61Ua6VJ2fS4pHLYJYTrGwHDQK2vZWBmALtx1V7R8uTqeu