CaverExample.java

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.ObjectWriter;
import com.klaytn.caver.Caver;
import com.klaytn.caver.abi.datatypes.Type;
import com.klaytn.caver.contract.Contract;
import com.klaytn.caver.contract.SendOptions;
import com.klaytn.caver.methods.response.TransactionReceipt;
import com.klaytn.caver.wallet.keyring.SingleKeyring;
import io.github.cdimascio.dotenv.Dotenv;
import okhttp3.Credentials;
import org.web3j.protocol.http.HttpService;

import java.math.BigInteger;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.List;

/**
 * Example code about "Dynamic ABI Loader"
 * Related article - Korean: https://medium.com/klaytn/caver-java-dynamic-abi-loader-8ccef10e7e68
 * Related article - English: https://medium.com/klaytn/caver-java-dynamic-abi-loader-5b116c9db673
 */
public class CaverExample {
    // You can directly input values for the variables below, or you can enter values in the caver-java-examples/.env file.
    private static String nodeApiUrl = ""; // e.g. "https://node-api.klaytnapi.com/v1/klaytn";
    private static String accessKeyId = ""; // e.g. "KASK1LVNO498YT6KJQFUPY8S";
    private static String secretAccessKey = ""; // e.g. "aP/reVYHXqjw3EtQrMuJP4A3/hOb69TjnBT3ePKG";
    private static String chainId = ""; // e.g. "1001" or "8217";
    private static String deployerAddress = ""; // e.g. "0xf5d3322418f2f2257d9255ad4a7ff1d50312d438"
    private static String deployerPrivateKey = ""; // e.g. "0x42f6375b608c2572fadb2ed9fd78c5c456ca3aa860c43192ad910c3269727fc7"

    public static void main(String[] args) {
        try {
            loadEnv();
            run();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static String objectToString(Object value) throws JsonProcessingException {
        ObjectWriter ow = new ObjectMapper().writer().withDefaultPrettyPrinter();
        return ow.writeValueAsString(value);
    }

    public static void loadEnv() {
        Dotenv env;
        String workingDirectory = System.getProperty("user.dir");
        Path workingDirectoryPath = Paths.get(workingDirectory);
        String projectRootDirectory = "caver-java-examples";
        String currentDirectoryName = workingDirectoryPath.getName(workingDirectoryPath.getNameCount() - 1).toString();
        String envDirectory = currentDirectoryName.equals(projectRootDirectory) ?
                workingDirectoryPath.toString() :
                workingDirectoryPath.getParent().getParent().toString();

        // Read `/path/to/caver-java-examples/.env` file.
        env = Dotenv.configure().directory(envDirectory).load();

        nodeApiUrl = nodeApiUrl.equals("") ? env.get("NODE_API_URL") : nodeApiUrl;
        accessKeyId = accessKeyId.equals("") ? env.get("ACCESS_KEY_ID") : accessKeyId;
        secretAccessKey = secretAccessKey.equals("") ? env.get("SECRET_ACCESS_KEY") : secretAccessKey;
        chainId = chainId.equals("") ? env.get("CHAIN_ID") : chainId;
        deployerAddress = deployerAddress.equals("") ? env.get("DEPLOYER_ADDRESS") : deployerAddress;
        deployerPrivateKey = deployerPrivateKey.equals("") ? env.get("DEPLOYER_PRIVATE_KEY") : deployerPrivateKey;
    }

    public static void run() throws Exception {
        HttpService httpService = new HttpService(nodeApiUrl);
        httpService.addHeader("Authorization", Credentials.basic(accessKeyId, secretAccessKey));
        httpService.addHeader("x-chain-id", chainId);
        Caver caver = new Caver(httpService);

        // abi and byteCode are extracted by compiling caver-java-boilerplate/resources/KVstore.sol
        String abi = "[\n" +
                "  {\n" +
                "    \"constant\":true,\n" +
                "    \"inputs\":[\n" +
                "      {\n" +
                "        \"name\":\"key\",\n" +
                "        \"type\":\"string\"\n" +
                "      }\n" +
                "    ],\n" +
                "    \"name\":\"get\",\n" +
                "    \"outputs\":[\n" +
                "      {\n" +
                "        \"name\":\"\",\n" +
                "        \"type\":\"string\"\n" +
                "      }\n" +
                "    ],\n" +
                "    \"payable\":false,\n" +
                "    \"stateMutability\":\"view\",\n" +
                "    \"type\":\"function\"\n" +
                "  },\n" +
                "  {\n" +
                "    \"constant\":false,\n" +
                "    \"inputs\":[\n" +
                "      {\n" +
                "        \"name\":\"key\",\n" +
                "        \"type\":\"string\"\n" +
                "      },\n" +
                "      {\n" +
                "        \"name\":\"value\",\n" +
                "        \"type\":\"string\"\n" +
                "      }\n" +
                "    ],\n" +
                "    \"name\":\"set\",\n" +
                "    \"outputs\":[],\n" +
                "    \"payable\":false,\n" +
                "    \"stateMutability\":\"nonpayable\",\n" +
                "    \"type\":\"function\"\n" +
                "  },\n" +
                "  {\n" +
                "    \"inputs\":[\n" +
                "      {\n" +
                "        \"name\":\"key\",\n" +
                "        \"type\":\"string\"\n" +
                "      },\n" +
                "      {\n" +
                "        \"name\":\"value\",\n" +
                "        \"type\":\"string\"\n" +
                "      }\n" +
                "    ],\n" +
                "    \"payable\":false,\n" +
                "    \"stateMutability\":\"nonpayable\",\n" +
                "    \"type\":\"constructor\"\n" +
                "  }\n" +
                "]";
        String byteCode = "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";
        Contract contract = caver.contract.create(abi);
        contract.getMethods().forEach((name, method) ->{
            System.out.println(method.getType() + " " +  caver.abi.buildFunctionString(method));
        });

        SingleKeyring deployerKeyring = caver.wallet.keyring.create(deployerAddress, deployerPrivateKey);
        caver.wallet.add(deployerKeyring);

        SendOptions sendOptions = new SendOptions(deployerKeyring.getAddress(), BigInteger.valueOf(650000));
        Contract deployedContract = contract.deploy(sendOptions, byteCode, "Just", "Test");
        System.out.println("Deployed address of contract: " + deployedContract.getContractAddress());

        TransactionReceipt.TransactionReceiptData receiptData = deployedContract.send(sendOptions, "set", "Just", "Test");
        System.out.println(objectToString(receiptData));

        List<Type> returnedData = deployedContract.call("get", "Just");
        System.out.println(objectToString(returnedData));
    }
}