CreateTokenDemo.java

import com.hedera.hashgraph.sdk.*;
import java.net.http.*;
import java.net.URI;
import com.google.gson.*;

public class CreateTokenDemo {
    public static void main(String[] args ) throws Exception {
        // .env-provided
        AccountId operatorId = AccountId.fromString(System.getenv("OPERATOR_ID"));
        PrivateKey operatorKey = PrivateKey.fromStringECDSA(System.getenv("OPERATOR_KEY"));
        String network = System.getenv().getOrDefault("HEDERA_NETWORK", "local"); // "local" for Solo
        String mirrorNode = System.getenv().getOrDefault(
            "MIRROR_NODE_URL",
            "http://localhost:38081/api/v1" 
        );

        if (operatorId == null || operatorKey == null) {
            throw new IllegalStateException("OPERATOR_ID / OPERATOR_KEY not set");
        }

        Client client =
            "local".equalsIgnoreCase(network)
                ? Client.forNetwork(java.util.Map.of("127.0.0.1:50211", new AccountId(3))) // Solo default node + node account (adjust if needed)
                : Client.forTestnet();

        client.setOperator(operatorId, operatorKey);
        System.out.println(operatorId);

        // generate token keys
        PrivateKey supplyKey = PrivateKey.generateECDSA();
        PrivateKey adminKey = supplyKey;

        // build & execute the token creation transaction
        TokenCreateTransaction transaction = new TokenCreateTransaction()
            .setTokenName("Demo Token")
            .setTokenSymbol("DEMO")
            .setDecimals(2)
            .setInitialSupply(100_000)
            .setSupplyType(TokenSupplyType.FINITE)
            .setMaxSupply(100_000)
            .setTreasuryAccountId(operatorId)
            .setAdminKey(adminKey.getPublicKey())
            .setSupplyKey(supplyKey.getPublicKey())
            .setTokenMemo("Created via tutorial")
            .freezeWith(client);

        TokenCreateTransaction signedTx = transaction.sign(adminKey);
        TransactionResponse txResponse = signedTx.execute(client);
        TransactionReceipt receipt = txResponse.getReceipt(client);
        TokenId tokenId = receipt.tokenId;

        System.out.println("\nFungible token created: " + tokenId );

        // Wait for Mirror Node to populate data
        System.out.println("\nWaiting for Mirror Node to update...");
        Thread.sleep(10000);

        // query balance using Mirror Node
        String mirrorNodeUrl = String.format(
        "%s/accounts/%s/tokens?token.id=%s",
        mirrorNode, operatorId, tokenId
        );
        
        HttpClient httpClient = HttpClient.newHttpClient( );
        HttpRequest request = HttpRequest.newBuilder().uri(URI.create(mirrorNodeUrl)).build();
        HttpResponse<String> response = httpClient.send(request, HttpResponse.BodyHandlers.ofString( ));

        try {
            if (response.statusCode() != 200) {
                System.out.println("Mirror Node returned status " + response.statusCode() + ". Skipping balance read.");
            } else {
                JsonObject data = new Gson().fromJson(response.body(), JsonObject.class);
                JsonArray tokens = (data != null) ? data.getAsJsonArray("tokens") : null;

                if (tokens != null && tokens.size() > 0) {
                    long balance = tokens.get(0).getAsJsonObject().get("balance").getAsLong();
                    System.out.println("\nTreasury holds: " + balance + " DEMO\n");
                } else {
                    System.out.println("Token balance not yet available in Mirror Node");
                }
            }
        } catch (Exception e) {
            System.out.println("Error reading token balance from Mirror Node: " + e.getMessage());
            // continue without failing
        }

        client.close();
    }
}