chore: update java version of examples

java-hello-world/00-create-fund-account/build.gradle

@@ -11,14 +11,8 @@ repositories {
 }
 
 dependencies {
-    implementation 'com.hedera.hashgraph:sdk:2.32.0'
-    implementation 'org.bouncycastle:bcprov-jdk15on:1.68'
+    implementation 'com.hedera.hashgraph:sdk:2.33.0'
     implementation 'io.github.cdimascio:java-dotenv:5.2.2'
-    implementation 'org.web3j:core:4.8.7'
-    implementation 'org.json:json:20211205'
-    testImplementation 'junit:junit:4.13.1'
-}
-
-tasks.named('test') {
-    useJUnitPlatform()
+    implementation 'com.google.code.gson:gson:2.10.1'
+    implementation 'org.slf4j:slf4j-nop:2.0.13'
 }

java-hello-world/00-create-fund-account/src/main/java/createfundaccount/ScriptCreateFundAccount.java

@@ -1,24 +1,25 @@
 package createfundaccount;
 
+import com.google.gson.JsonArray;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParser;
+import com.hedera.hashgraph.sdk.Hbar;
+import com.hedera.hashgraph.sdk.Mnemonic;
 import com.hedera.hashgraph.sdk.PrivateKey;
-import org.bouncycastle.jce.provider.BouncyCastleProvider;
-import org.json.JSONArray;
-import org.json.JSONObject;
-import org.web3j.crypto.Bip32ECKeyPair;
-import org.web3j.crypto.Credentials;
-import org.web3j.crypto.MnemonicUtils;
+import com.hedera.hashgraph.sdk.PublicKey;
 import io.github.cdimascio.dotenv.Dotenv;
-
-import java.net.HttpURLConnection;
 import java.net.URI;
-import java.net.URL;
-import java.util.Scanner;
-import java.security.Security;
-import java.text.NumberFormat;
-import java.util.Locale;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
 
 public class ScriptCreateFundAccount {
     public static void main(String[] args) throws Exception {
+
+        // Generate seed phrase
+//        Mnemonic seedPhraseMnemonic = Mnemonic.generate12();
+//        System.out.println("Seed phrase: " + seedPhraseMnemonic.toString());
+
         // Load environment variables from .env file
         Dotenv dotenv = Dotenv.load();
 
@@ -27,76 +28,36 @@ public static void main(String[] args) throws Exception {
             throw new IllegalArgumentException("Please set required keys in .env file.");
         }
 
-        // Create an ECSDA secp256k1 private key based on a BIP-39 seed phrase,
-        // plus the default BIP-32/BIP-44 HD Wallet derivation path used by Metamask.
-        Security.addProvider(new BouncyCastleProvider());
-
-        // BIP-39 Generate seed from seed phrase
-        byte[] seed = MnemonicUtils.generateSeed(seedPhrase, null);
-
-        // BIP-32 Derive master key
-        Bip32ECKeyPair masterKeypair = Bip32ECKeyPair.generateKeyPair(seed);
-        final int[] path = {
-            44 | Bip32ECKeyPair.HARDENED_BIT,
-            60 | Bip32ECKeyPair.HARDENED_BIT,
-            0 | Bip32ECKeyPair.HARDENED_BIT,
-            0,
-            0
-        };
-
-        // BIP-44 Derive private key of single account from BIP-32 master key + BIP-44 HD path
-        // Using m/44'/60'/0'/0/0 for compatibility with Metamask hardcoded default
-        Bip32ECKeyPair derivedKeypair = Bip32ECKeyPair.deriveKeyPair(masterKeypair, path);
-        Credentials credentials = Credentials.create(derivedKeypair);
-        String privateKeyString = credentials.getEcKeyPair().getPrivateKey().toString(16);
-        final int privateKeyStringMissingCharCount = 64 - privateKeyString.length();
-        if (privateKeyStringMissingCharCount > 0) {
-            privateKeyString = ("0").repeat(privateKeyStringMissingCharCount) + privateKeyString;
-        }
-        PrivateKey privateKey = PrivateKey.fromStringECDSA(privateKeyString);
+        // Derive private key
+        PrivateKey privateKey = Mnemonic.fromString(seedPhrase).toStandardECDSAsecp256k1PrivateKey("", 0);
+        PublicKey publicKey = privateKey.getPublicKey();
 
         // At this point the account technically does not yet exist,
         // and will need to be created when it receives its first transaction (later).
         // Convert the private key to string format as well as an EVM address.
         String privateKeyHex = "0x" + privateKey.toStringRaw();
-        String evmAddress = credentials.getAddress();
+
+        // Derive EVM address
+        String evmAddress = "0x" + publicKey.toEvmAddress().toString();
         String accountExplorerUrl = "https://hashscan.io/testnet/account/" + evmAddress;
         String accountBalanceFetchApiUrl = "https://testnet.mirrornode.hedera.com/api/v1/balances?account.id=" + evmAddress + "&limit=1&order=asc";
 
         // Query account ID and balance using mirror node API
-        Long accountBalanceTinybar = null;
-        String accountBalanceHbar = null;
-        String accountId = null;
-        try {
-            URL url = URI.create(accountBalanceFetchApiUrl).toURL();
-            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
-            conn.setRequestMethod("GET");
-            conn.connect();
-            int responseCode = conn.getResponseCode();
-            if (responseCode < 200 || responseCode >= 400) {
-                throw new RuntimeException("HTTP response code: " + responseCode);
-            }
-            String inline = "";
-            Scanner scanner = new Scanner(url.openStream());
-            while (scanner.hasNext()) {
-                inline += scanner.nextLine();
-            }
-            scanner.close();
+        final HttpRequest httpRequest = HttpRequest.newBuilder()
+                .uri(URI.create(accountBalanceFetchApiUrl))
+                .build();
 
-            JSONObject jsonResponse = new JSONObject(inline);
-            JSONArray balancesArray = jsonResponse.getJSONArray("balances");
-            JSONObject balanceObject = balancesArray.getJSONObject(0);
-            accountId = balanceObject.getString("account");
-            accountBalanceTinybar = balanceObject.getLong("balance");
-        } catch (Exception e) {
-            // do nothing
-        }
+        final HttpClient httpClient = HttpClient.newHttpClient();
 
-        if (accountBalanceTinybar != null) {
-            accountBalanceHbar = NumberFormat
-                .getNumberInstance(Locale.UK)
-                .format(accountBalanceTinybar * Math.pow(10, -8));
-        }
+        final var mirrorNodeResponse = httpClient.send(httpRequest, HttpResponse.BodyHandlers.ofString()).body();
+
+        JsonObject jsonResponse = JsonParser.parseString(mirrorNodeResponse).getAsJsonObject();
+        JsonArray balancesArray = jsonResponse.getAsJsonArray("balances");
+        JsonObject balanceObject = balancesArray.get(0).getAsJsonObject();
+        String accountId = balanceObject.get("account").getAsString();
+        long accountBalanceTinybar = balanceObject.get("balance").getAsLong();
+
+        Hbar accountBalanceHbar = Hbar.fromTinybars(accountBalanceTinybar);
 
         // Output results
         System.out.println("privateKeyHex: " + privateKeyHex);

java-hello-world/01-hfs-files/build.gradle

@@ -11,14 +11,9 @@ repositories {
 }
 
 dependencies {
-    implementation 'com.hedera.hashgraph:sdk:2.32.0'
-    implementation 'io.github.cdimascio:dotenv-java:2.3.2'
+    implementation 'com.hedera.hashgraph:sdk:2.33.0'
     implementation 'io.grpc:grpc-netty-shaded:1.57.2'
-    implementation 'org.slf4j:slf4j-nop:2.0.9'
-    implementation 'com.google.code.gson:gson:2.8.8'
-    testRuntimeOnly 'org.junit.platform:junit-platform-launcher'
-}
-
-tasks.named('test') {
-    useJUnitPlatform()
+    implementation 'io.github.cdimascio:java-dotenv:5.2.2'
+    implementation 'com.google.code.gson:gson:2.10.1'
+    implementation 'org.slf4j:slf4j-nop:2.0.13'
 }

java-hello-world/01-hfs-files/src/main/java/hfsfiles/ScriptHfsFiles.java

@@ -1,11 +1,18 @@
 package hfsfiles;
 
-import com.hedera.hashgraph.sdk.*;
+import com.hedera.hashgraph.sdk.AccountId;
+import com.hedera.hashgraph.sdk.Client;
+import com.hedera.hashgraph.sdk.FileContentsQuery;
+import com.hedera.hashgraph.sdk.FileCreateTransaction;
+import com.hedera.hashgraph.sdk.FileId;
+import com.hedera.hashgraph.sdk.PrivateKey;
+import com.hedera.hashgraph.sdk.TransactionId;
+import com.hedera.hashgraph.sdk.TransactionReceipt;
+import com.hedera.hashgraph.sdk.TransactionResponse;
 import io.github.cdimascio.dotenv.Dotenv;
-
-import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Paths;
+import java.util.Objects;
 
 public class ScriptHfsFiles {
     public static void main(String[] args) throws Exception {
@@ -26,9 +33,9 @@ public static void main(String[] args) throws Exception {
         Client client = Client.forTestnet().setOperator(accountId, accountKey);
 
         // Read file from disk
-        String localFileContents = new String(Files.readAllBytes(Paths.get("my-file.txt")), StandardCharsets.UTF_8);
+        String localFileContents = Files.readString(Paths.get("my-file.txt"));
 
-        // Write file onto Hedera Testnet, using HFS FileCreateTransaction
+        // Write file onto Hedera Testnet, using HFS FileCreateTransaction
         FileCreateTransaction fileCreateTx = new FileCreateTransaction()
             // NOTE: File create transaction
             // Step (1) in the accompanying tutorial
@@ -39,7 +46,7 @@ public static void main(String[] args) throws Exception {
         TransactionResponse fileCreateTxSubmitted = fileCreateTxSigned.execute(client);
         TransactionId fileCreateTxId = fileCreateTxSubmitted.transactionId;
         TransactionReceipt fileCreateTxReceipt = fileCreateTxSubmitted.getReceipt(client);
-        FileId fileId = fileCreateTxReceipt.fileId;
+        FileId fileId = Objects.requireNonNull(fileCreateTxReceipt.fileId);
 
         // Read file from Hedera Testnet, using HFS FileContentsQuery
         FileContentsQuery fileReadQuery = new FileContentsQuery()

java-hello-world/02-hscs-smart-contract-sdk/build.gradle

@@ -11,14 +11,9 @@ repositories {
 }
 
 dependencies {
-    implementation 'com.hedera.hashgraph:sdk:2.32.0'
-    implementation 'io.github.cdimascio:dotenv-java:2.3.2'
+    implementation 'com.hedera.hashgraph:sdk:2.33.0'
     implementation 'io.grpc:grpc-netty-shaded:1.57.2'
-    implementation 'org.slf4j:slf4j-nop:2.0.9'
-    implementation 'com.google.code.gson:gson:2.8.8'
-    testRuntimeOnly 'org.junit.platform:junit-platform-launcher'
-}
-
-tasks.named('test') {
-    useJUnitPlatform()
+    implementation 'io.github.cdimascio:java-dotenv:5.2.2'
+    implementation 'com.google.code.gson:gson:2.10.1'
+    implementation 'org.slf4j:slf4j-nop:2.0.13'
 }

java-hello-world/02-hscs-smart-contract-sdk/src/main/java/hscssmartcontract/ScriptHscsSmartContract.java

@@ -1,12 +1,23 @@
 package hscssmartcontract;
 
-import com.hedera.hashgraph.sdk.*;
+import com.hedera.hashgraph.sdk.AccountId;
+import com.hedera.hashgraph.sdk.Client;
+import com.hedera.hashgraph.sdk.ContractCallQuery;
+import com.hedera.hashgraph.sdk.ContractCreateTransaction;
+import com.hedera.hashgraph.sdk.ContractExecuteTransaction;
+import com.hedera.hashgraph.sdk.ContractFunctionParameters;
+import com.hedera.hashgraph.sdk.ContractFunctionResult;
+import com.hedera.hashgraph.sdk.ContractId;
+import com.hedera.hashgraph.sdk.FileCreateTransaction;
+import com.hedera.hashgraph.sdk.FileId;
+import com.hedera.hashgraph.sdk.PrivateKey;
+import com.hedera.hashgraph.sdk.TransactionId;
+import com.hedera.hashgraph.sdk.TransactionReceipt;
+import com.hedera.hashgraph.sdk.TransactionResponse;
 import io.github.cdimascio.dotenv.Dotenv;
-
-import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Paths;
-import java.util.concurrent.TimeoutException;
+import java.util.Objects;
 
 public class ScriptHscsSmartContract {
     public static void main(String[] args) throws Exception {
@@ -37,15 +48,15 @@ public static void main(String[] args) throws Exception {
             .setContents(evmBytecode)
             .execute(client);
         TransactionReceipt fileReceipt = fileCreateTransaction.getReceipt(client);
-        FileId bytecodeFileId = fileReceipt.fileId;
+        FileId bytecodeFileId = Objects.requireNonNull(fileReceipt.fileId);
 
 	    // Deploy smart contract
         TransactionResponse contractCreateTransaction = new ContractCreateTransaction()
             .setBytecodeFileId(bytecodeFileId)
-            .setGas(100000)
+            .setGas(100_000)
             .execute(client);
         TransactionReceipt contractReceipt = contractCreateTransaction.getReceipt(client);
-        ContractId myContractId = contractReceipt.contractId;
+        ContractId myContractId = Objects.requireNonNull(contractReceipt.contractId);
         String myContractExplorerUrl = "https://hashscan.io/testnet/address/" + myContractId;
 
         // Write data to smart contract
@@ -54,7 +65,7 @@ public static void main(String[] args) throws Exception {
         // .setFunction("introduce", new ContractFunctionParameters().addString(/* ... */))
         TransactionResponse contractExecuteTransaction = new ContractExecuteTransaction()
             .setContractId(myContractId)
-            .setGas(100000)
+            .setGas(100_000)
             .setFunction("introduce", new ContractFunctionParameters().addString("bguiz"))
             .execute(client);
         TransactionReceipt executeReceipt = contractExecuteTransaction.getReceipt(client);
@@ -69,7 +80,7 @@ public static void main(String[] args) throws Exception {
         //  .setFunction(/* ... */);
         ContractCallQuery contractCallQuery = new ContractCallQuery()
             .setContractId(myContractId)
-            .setGas(100000)
+            .setGas(100_000)
             .setFunction("greet", new ContractFunctionParameters());
         ContractFunctionResult greetResult = contractCallQuery.execute(client);
         String myContractQueryResult = greetResult.getString(0);

java-hello-world/04-hts-ft/build.gradle

@@ -11,15 +11,9 @@ repositories {
 }
 
 dependencies {
-    implementation 'com.hedera.hashgraph:sdk:2.32.0'
-    implementation 'io.github.cdimascio:dotenv-java:2.3.2'
+    implementation 'com.hedera.hashgraph:sdk:2.33.0'
     implementation 'io.grpc:grpc-netty-shaded:1.57.2'
-    implementation 'org.slf4j:slf4j-nop:2.0.9'
-    implementation 'com.google.code.gson:gson:2.8.8'
-    implementation 'org.json:json:20211205'
-    testRuntimeOnly 'org.junit.platform:junit-platform-launcher'
-}
-
-tasks.named('test') {
-    useJUnitPlatform()
+    implementation 'io.github.cdimascio:java-dotenv:5.2.2'
+    implementation 'com.google.code.gson:gson:2.10.1'
+    implementation 'org.slf4j:slf4j-nop:2.0.13'
 }