java-vsystems

Java library for V Systems

Install

1. To use this SDK, we need Java 1.8. First of all, update the repository

   $ sudo apt-get update

   Install Java in your machine

   $ sudo apt-get install openjdk-8-jdk

   Check Java version (remove the old version Java if needed).

   $ java -version
   openjdk version "1.8.0_181"
   OpenJDK Runtime Environment (build 1.8.0_181-8u181-b13-0ubuntu0.16.04.1-b13)
   OpenJDK 64-Bit Server VM (build 25.181-b13, mixed mode)

2. clone this project

   $ git clone https://github.com/virtualeconomy/java-v-sdk.git

3. import GSON jar to your project. You can download gson.jar from Gson Release. If you are using Maven, you can add dependency looks like this:

   <dependency>
       <groupId>com.google.code.gson</groupId>
       <artifactId>gson</artifactId>
       <version>2.8.5</version>
   </dependency>
   

Usage

Create chain object

1. For testnet chain:

   import v.systems.Blockchain;
   import v.systems.type.NetworkType;
   
   Blockchain chain = new Blockchain(NetworkType.Testnet, "http://test.v.systems:9922");

2. For mainnet chain:

   import v.systems.Blockchain;
   import v.systems.type.NetworkType;
   
   Blockchain chain = new Blockchain(NetworkType.Mainnet, "https://wallet.v.systems/api");

3. Call node internal used API with API key (to avoid Provided API key is not correct error):

   import v.systems.Blockchain;
   import v.systems.type.NetworkType;
   
   Blockchain chain = new Blockchain(NetworkType.Testnet, "http://test.v.systems:9922", "<API_KEY>");
   List<Transaction> txList = chain.getActiveLeaseTransactions(testAddress);

Create address object

1. Create account by seed

   import v.systems.Account;
   import v.systems.type.NetworkType;
   
   Account acc = new Account(NetworkType.Testnet, "<your seed>", 0);

2. Create account by private key

   import v.systems.Account;
   import v.systems.type.NetworkType;
    
   Account acc = new Account(NetworkType.Testnet, "<base58 private key>");

3. Create account by public key

   import v.systems.Account;
   import v.systems.type.NetworkType;
    
   Account acc = new Account(NetworkType.Testnet, "<base58 public key>", null);

4. Create account by address

   import v.systems.Account;
   import v.systems.type.NetworkType;
    
   Account acc = new Account(NetworkType.Testnet, null, "<base58 address>");

Send transaction

1. Send Payment transaction

   Long amount = 1 * Blockchain.V_UNITY;  // Send 1.0 V coin
   PaymentTransaction tx = TransactionFactory.buildPaymentTx("<recipient address>", amount);
   String txId = tx.getId(); // get Tx ID offline
   
   // Usage 1: for hot wallet sending transaction
   Transaction result = acc.sendTransaction(chain, tx);
   
   // Usage 2: for cold wallet signing transaction
   String signature = acc.getSignature(tx);

2. Send Lease transaction

   Long amount = 1 * Blockchain.V_UNITY;  // Lease 1.0 V coin
   LeaseTransaction tx = TransactionFactory.buildLeaseTx("<recipient address>", amount);
   String txId = tx.getId(); // get Tx ID offline
   
   // Usage 1: for hot wallet sending transaction
   Transaction result = acc.sendTransaction(chain, tx);
   
   // Usage 2: for cold wallet signing transaction
   String signature = acc.getSignature(tx);

3. Send Token by executing contract function

   First of all, if we do not know any Token information, we could get information by tokenId

   ContractType tokenType = chain.getContractTypeByTokenId(tokenId);
   TokenInfo tokenInfo = chain.getTokenInfo(tokenId);
   Long tokenUnity = tokenInfo.getUnity();

   Then we send the token by executing contract function

   Long amount = 1 * tokenUnity;  // Send 1.0 Token
   ExecuteContractFunctionTransaction tx = TransactionFactory.buildSendTokenTx(tokenId, tokenType,"<recipient address>", amount);
   String txId = tx.getId(); // get Tx ID offline
   
   // Usage 1: for hot wallet sending transaction
   Transaction result = acc.sendTransaction(chain, tx);
   
   // Usage 2: for cold wallet signing transaction
   String signature = acc.getSignature(tx);