Smart Contract Assets

Zetrix Smart Contract Assets Example

Overview

Zetrix smart contracts are written in JavaScript, conforming to the ECMAScript standard (ECMA-262). Each contract must define two key functions:

• init: The initialization function

• main: The execution entry point

Both functions accept a single input parameter, input, which is a string specified at the time of contract invocation.

Additional Resources

• For contract fundamentals, see Introduction to Smart Contract.

• For coding rules and standards, refer to Syntax in Smart Contract.

Java-based Development Scenarios

This section outlines three Java-integrated smart contract scenarios:

1. Scenario One: Implements contract creation

2. Scenario Two: Implements contract triggering

3. Scenario Three: Implements contract querying

Each scenario provides contract code examples aligned with real use cases.

'use strict';

let globalAttribute = {};
const globalAttributeKey = 'global_attribute';

function makeAllowanceKey(owner, spender){
    return 'allow_' + owner + '_to_' + spender;
}

function approve(spender, value){
    assert(addressCheck(spender) === true, 'Arg-spender is not a valid address.');
    assert(stoI64Check(value) === true, 'Arg-value must be alphanumeric.');
    assert(int64Compare(value, '0') > 0, 'Arg-value of spender ' + spender + ' must be greater than 0.');

    let key = makeAllowanceKey(sender, spender);
    storageStore(key, value);

    tlog('approve', sender, spender, value);

    return true;
}

function allowance(owner, spender){
    assert(addressCheck(owner) === true, 'Arg-owner is not a valid address.');
    assert(addressCheck(spender) === true, 'Arg-spender is not a valid address.');

    let key = makeAllowanceKey(owner, spender);
    let value = storageLoad(key);
    assert(value !== false, 'Failed to get the allowance given to ' + spender + ' by ' + owner + ' from metadata.');

    return value;
}

function transfer(to, value){
    assert(addressCheck(to) === true, 'Arg-to is not a valid address.');
    assert(stoI64Check(value) === true, 'Arg-value must be alphanumeric.');
    assert(int64Compare(value, '0') > 0, 'Arg-value must be greater than 0.');
    if(sender === to) {
        tlog('transfer', sender, to, value);  
        return true;
    }
    
    let senderValue = storageLoad(sender);
    assert(senderValue !== false, 'Failed to get the balance of ' + sender + ' from metadata.');
    assert(int64Compare(senderValue, value) >= 0, 'Balance:' + senderValue + ' of sender:' + sender + ' < transfer value:' + value + '.');

    let toValue = storageLoad(to);
    toValue = (toValue === false) ? value : int64Add(toValue, value); 
    storageStore(to, toValue);

    senderValue = int64Sub(senderValue, value);
    storageStore(sender, senderValue);

    tlog('transfer', sender, to, value);

    return true;
}

function transferFrom(from, to, value){
    assert(addressCheck(from) === true, 'Arg-from is not a valid address.');
    assert(addressCheck(to) === true, 'Arg-to is not a valid address.');
    assert(stoI64Check(value) === true, 'Arg-value must be alphanumeric.');
    assert(int64Compare(value, '0') > 0, 'Arg-value must be greater than 0.');
    
    if(from === to) {
        tlog('transferFrom', sender, from, to, value);
        return true;
    }
    
    let fromValue = storageLoad(from);
    assert(fromValue !== false, 'Failed to get the value, probably because ' + from + ' has no value.');
    assert(int64Compare(fromValue, value) >= 0, from + ' Balance:' + fromValue + ' < transfer value:' + value + '.');

    let allowValue = allowance(from, sender);
    assert(int64Compare(allowValue, value) >= 0, 'Allowance value:' + allowValue + ' < transfer value:' + value + ' from ' + from + ' to ' + to  + '.');

    let toValue = storageLoad(to);
    toValue = (toValue === false) ? value : int64Add(toValue, value); 
    storageStore(to, toValue);

    fromValue = int64Sub(fromValue, value);
    storageStore(from, fromValue);

    let allowKey = makeAllowanceKey(from, sender);
    allowValue   = int64Sub(allowValue, value);
    storageStore(allowKey, allowValue);

    tlog('transferFrom', sender, from, to, value);

    return true;
}

function balanceOf(address){
    assert(addressCheck(address) === true, 'Arg-address is not a valid address.');

    let value = storageLoad(address);
    assert(value !== false, 'Failed to get the balance of ' + address + ' from metadata.');
    return value;
}

function init(input_str){
    let params = JSON.parse(input_str).params;

    assert(stoI64Check(params.totalSupply) === true && params.totalSupply > 0 &&
           typeof params.name === 'string' && params.name.length > 0 &&
           typeof params.symbol === 'string' && params.symbol.length > 0 &&
           typeof params.decimals === 'number' && params.decimals >= 0, 
           'Failed to check args');
       
    globalAttribute.totalSupply = params.totalSupply;
    globalAttribute.name = params.name;
    globalAttribute.symbol = params.symbol;
    globalAttribute.version = 'Contract20';
    globalAttribute.decimals = params.decimals;
    
    storageStore(globalAttributeKey, JSON.stringify(globalAttribute));
    storageStore(sender, globalAttribute.totalSupply);
}

function main(input_str){
    let input = JSON.parse(input_str);

    if(input.method === 'transfer'){
        transfer(input.params.to, input.params.value);
    }
    else if(input.method === 'transferFrom'){
        transferFrom(input.params.from, input.params.to, input.params.value);
    }
    else if(input.method === 'approve'){
        approve(input.params.spender, input.params.value);
    }
    else{
        throw '<Main interface passes an invalid operation type>';
    }
}

function query(input_str){
    let result = {};
    let input  = JSON.parse(input_str);

    if(input.method === 'tokenInfo'){
        globalAttribute = JSON.parse(storageLoad(globalAttributeKey));
        result.tokenInfo = globalAttribute;
    }
    else if(input.method === 'allowance'){
        result.allowance = allowance(input.params.owner, input.params.spender);
    }
    else if(input.method === 'balanceOf'){
        result.balance = balanceOf(input.params.address);
    }
    else{
        throw '<Query interface passes an invalid operation type>';
    }
    return JSON.stringify(result);
}

Scenario One

An asset issuer issues smart contract assets, the total amount of which is 1 billion, the issuance code is CGO, and the name is Contract Global. The details are as follows:

Field	Required?	Example	Description
name	Yes	Contract Global	token name
symbol	Yes	CGO	token code
decimals	Yes	8	Precision
totalSupply	Yes	1000000000	total amount

The execution flow for this scenario consists of the following steps:

1. Compressing Text – Minify the smart contract code before deployment.

2. Creating SDK Instances – Initialize the SDK to interact with the Zetrix blockchain.

3. Creating the Asset Issuer Account – Generate the account that will issue digital assets.

4. Activating the Asset Issuer Account – Fund the account to make it active on-chain.

5. Obtaining the Serial Number (Nonce) – Retrieve the current nonce of the issuer account.

6. Assembling the Contract Account Creation and CGO Token Issuance – Prepare the transaction payload combining account creation and token issuance.

7. Serializing the Transaction – Convert the transaction into a byte stream format.

8. Signing the Transaction – Use the private key to sign the serialized transaction.

9. Sending the Transaction – Submit the signed transaction to the Zetrix network.

10. Querying Execution Status – Check whether the transaction was successfully processed.

Compressing Text

Open the online text compression page: tool from the third party , copy the verified smart contract code to the edit box on the page, then click the Compress button to copy the compressed string, as shown below:

Creating SDK Instances-1

Create an instance and set the url (the IP and port of a deployed node).

Environment description:

Network Environment	IP
Experience Zetrix	seed1-node.zetrix.com

Sample code

 String url = "http://seed1-node.zetrix.com"; 
 SDK sdk = SDK.getInstance(url); 

In the Zetrix network, each block is generated every 10 seconds, and each transaction requires only one confirmation to get the final state of the transaction.

Creating the Asset Issuer Account

The code to create the asset issuer account is as follows:

public static AccountCreateResult createAccount() { 
    AccountCreateResponse response = sdk.getAccountService().create(); 
    if (response.getErrorCode() != 0) { 
        return null; 
    } 
    return response.getResult(); 
}

Return value:

 AccountCreateResult 
   address: ztxShU1adq9TLLxfnua92oJkS5NPeEKbxy4iY 
   privateKey: privbyYK6NwBJbcgK9yGx6tQ7swXG45t4WT7fgS29Y8v8Cyd2NZeLKXG 
   publicKey: b001526ae8b7542c9c84583e926705ff4f27725e2c5ce63dce07e4d22186fb43304a02ab6fce

Note: An account created in this way is an account that is not activated.

Activating the Asset Issuer Account

When the account is not activated, it needs to be activated by an activated (chained) account. Please skip this section if your account has been activated.

Note: Use an activated account to transfer gas to an inactive account.

Obtaining the Serial Number of the Asset Issuer Account-1

Each account maintains its own serial number, which starts from 1 and is incremented. A serial number marks a transaction for that account. The code to obtain the serial number of the asset issuer account is as follows:

 public long getAccountNonce() {
 long nonce = 0;

    // Init request
    String accountAddress = [address of the asset issuer account];
    AccountGetNonceRequest request = new AccountGetNonceRequest();
    request.setAddress(accountAddress);
    
    // Call getNonce
    AccountGetNonceResponse response = sdk.getAccountService().getNonce(request);
    if (0 == response.getErrorCode()) {
        nonce = response.getResult().getNonce();
    } else {
        System.out.println("error: " + response.getErrorDesc());
 }
 return nonce;
 }

Return value:

 nonce: 6

Note: If an account is not queried, it means that the account is not activated.

Assembling the Creation of the Contract Account and the CGO Token Issuance

The code assigns the compressed contract code to the payload variable. The specific code is as follows:

 public BaseOperation[] buildOperations() { 
     // The account address to issue apt1.0 token 
     String createContractAddress = "ztxSXVGt5ujjAe4hr11VqhjWpJdKqn6QfDVUX"; 
     // Contract account initialization Gas，the unit is UGas，and 1 Gas = 10^8 UGas 
     Long initBalance = ToBaseUnit.ToUGas("0.01"); 
     // The token name 
     String name = "Contract Global"; 
     // The token code 
     String symbol = "CGO"; 
     // The token total supply, which includes the dicimals.
     // If decimals is 8 and you want to issue 10 assets now, the nowSupply must be 10 * 10 ^ 8, like below.
     String totalSupply = "1000000000";
     // The token decimals 
     Integer decimals = 8; 
     // Contract code 
     String payload = "'use strict';let globalAttribute={};const globalAttributeKey='global_attribute';function makeAllowanceKey(owner,spender){return'allow_'+owner+'_to_'+spender;}function approve(spender,value){assert(addressCheck(spender)===true,'Arg-spender is not a valid address.');assert(stoI64Check(value)===true,'Arg-value must be alphanumeric.');assert(int64Compare(value,'0')>0,'Arg-value of spender '+spender+' must be greater than 0.');let key=makeAllowanceKey(sender,spender);storageStore(key,value);tlog('approve',sender,spender,value);return true;}function allowance(owner,spender){assert(addressCheck(owner)===true,'Arg-owner is not a valid address.');assert(addressCheck(spender)===true,'Arg-spender is not a valid address.');let key=makeAllowanceKey(owner,spender);let value=storageLoad(key);assert(value!==false,'Failed to get the allowance given to '+spender+' by '+owner+' from metadata.');return value;}function transfer(to,value){assert(addressCheck(to)===true,'Arg-to is not a valid address.');assert(stoI64Check(value)===true,'Arg-value must be alphanumeric.');assert(int64Compare(value,'0')>0,'Arg-value must be greater than 0.');if(sender===to){tlog('transfer',sender,to,value);return true;}let senderValue=storageLoad(sender);assert(senderValue!==false,'Failed to get the balance of '+sender+' from metadata.');assert(int64Compare(senderValue,value)>=0,'Balance:'+senderValue+' of sender:'+sender+' < transfer value:'+value+'.');let toValue=storageLoad(to);toValue=(toValue===false)?value:int64Add(toValue,value);storageStore(to,toValue);senderValue=int64Sub(senderValue,value);storageStore(sender,senderValue);tlog('transfer',sender,to,value);return true;}function transferFrom(from,to,value){assert(addressCheck(from)===true,'Arg-from is not a valid address.');assert(addressCheck(to)===true,'Arg-to is not a valid address.');assert(stoI64Check(value)===true,'Arg-value must be alphanumeric.');assert(int64Compare(value,'0')>0,'Arg-value must be greater than 0.');if(from===to){tlog('transferFrom',sender,from,to,value);return true;}let fromValue=storageLoad(from);assert(fromValue!==false,'Failed to get the value, probably because '+from+' has no value.');assert(int64Compare(fromValue,value)>=0,from+' Balance:'+fromValue+' < transfer value:'+value+'.');let allowValue=allowance(from,sender);assert(int64Compare(allowValue,value)>=0,'Allowance value:'+allowValue+' < transfer value:'+value+' from '+from+' to '+to+'.');let toValue=storageLoad(to);toValue=(toValue===false)?value:int64Add(toValue,value);storageStore(to,toValue);fromValue=int64Sub(fromValue,value);storageStore(from,fromValue);let allowKey=makeAllowanceKey(from,sender);allowValue=int64Sub(allowValue,value);storageStore(allowKey,allowValue);tlog('transferFrom',sender,from,to,value);return true;}function balanceOf(address){assert(addressCheck(address)===true,'Arg-address is not a valid address.');let value=storageLoad(address);assert(value!==false,'Failed to get the balance of '+address+' from metadata.');return value;}function init(input_str){let params=JSON.parse(input_str).params;assert(stoI64Check(params.totalSupply)===true&&params.totalSupply>0&&typeof params.name==='string'&&params.name.length>0&&typeof params.symbol==='string'&&params.symbol.length>0&&typeof params.decimals==='number'&&params.decimals>=0,'Failed to check args');globalAttribute.totalSupply=params.totalSupply;globalAttribute.name=params.name;globalAttribute.symbol=params.symbol;globalAttribute.version='Contract20';globalAttribute.decimals=params.decimals;storageStore(globalAttributeKey,JSON.stringify(globalAttribute));storageStore(sender,globalAttribute.totalSupply);}function main(input_str){let input=JSON.parse(input_str);if(input.method==='transfer'){transfer(input.params.to,input.params.value);}else if(input.method==='transferFrom'){transferFrom(input.params.from,input.params.to,input.params.value);}else if(input.method==='approve'){approve(input.params.spender,input.params.value);}else{throw'<Main interface passes an invalid operation type>';}}function query(input_str){let result={};let input=JSON.parse(input_str);if(input.method==='tokenInfo'){globalAttribute=JSON.parse(storageLoad(globalAttributeKey));result.tokenInfo=globalAttribute;}else if(input.method==='allowance'){result.allowance=allowance(input.params.owner,input.params.spender);}else if(input.method==='balanceOf'){result.balance=balanceOf(input.params.address);}else{throw'<Query interface passes an invalid operation type>';}return JSON.stringify(result);}"; 

     // Init initInput 
     JSONObject initInput = new JSONObject(); 
     JSONObject params = new JSONObject(); 
     params.put("name", name); 
     params.put("symbol", symbol); 
     params.put("decimals", decimals); 
     params.put("totalSupply", totalSupply);
     initInput.put("params", params);  

     // Build create contract operation 
     ContractCreateOperation contractCreateOperation = new ContractCreateOperation(); 
     contractCreateOperation.setSourceAddress(createContractAddress); 
     contractCreateOperation.setInitBalance(initBalance); 
     contractCreateOperation.setPayload(payload); 
     contractCreateOperation.setInitInput(initInput.toJSONString()); 
     contractCreateOperation.setMetadata("create contract"); 

     BaseOperation[] operations = { contractCreateOperation }; 
     return operations; 
 } 

Serializing the Transaction-1

Serializing transactions is for the convenience network transmission.

Note:

• feeLimit: the maximum transaction fee that the originator of this transaction will pay for this transaction. Please fill in 10.08Gas for the issuance of this asset.

• nonce: the transaction serial number of the originator of this transaction, which is obtained by adding 1 to the nonce value of the current account.

The specific code of serializing transactions is as follows. The parameter nonce in the example is the account serial number obtained by calling getAccountNonce, and the parameter operations is the asset issuance operation obtained by calling buildOperations.

 public String seralizeTransaction(Long nonce,  BaseOperation[] operations) { 
    String transactionBlob = null; 

    // The account address to create contracts and issue assets 
    String senderAddresss = "ztxSXVGt5ujjAe4hr11VqhjWpJdKqn6QfDVUX"; 
    // The gasPrice is fixed at 1000L, the unit is UGas 
    Long gasPrice = 1000L; 
    // Set up the maximum cost 10.08Gas 
    Long feeLimit = ToBaseUnit.ToUGas("10.08"); 
    // Nonce should add 1 
    nonce += 1; 

    // Build transaction  Blob 
    TransactionBuildBlobRequest transactionBuildBlobRequest = new TransactionBuildBlobRequest(); 
    transactionBuildBlobRequest.setSourceAddress(senderAddresss); 
    transactionBuildBlobRequest.setNonce(nonce); 
    transactionBuildBlobRequest.setFeeLimit(feeLimit); 
    transactionBuildBlobRequest.setGasPrice(gasPrice); 
    for (int i = 0; i < operations.length; i++) { 
        transactionBuildBlobRequest.addOperation(operations[i]); 
    } 
    TransactionBuildBlobResponse transactionBuildBlobResponse = sdk.getTransactionService().buildBlob(transactionBuildBlobRequest); 
    if (transactionBuildBlobResponse.getErrorCode() == 0) { 
    transactionBlob = transactionBuildBlobResponse. getResult().getTransactionBlob(); 
    } else { 
        System.out.println("error: " + transactionBuildBlobResponse.getErrorDesc()); 
    } 
    return transactionBlob; 
 } 

Return value:

 transactionBlob: 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

Signing the Transaction-1

All transactions need to be signed, and a transaction will not take effect until it is signed. The signature result includes signature data and a public key. The specific code for signing transactions is as follows. The parameter transactionBlob in the example is the serialized transaction string obtained by calling seralizeTransaction.

 public Signature[] signTransaction(String transactionBlob) { 
    Signature[] signatures = null; 
    // The account private key to create contract and issue token 
    String senderPrivateKey = "privbs4iBCugQeb2eiycU8RzqkPqd28eaAYrRJGwtJTG8FVHjwAyjiyC"; 

    // Sign transaction BLob 
    TransactionSignRequest transactionSignRequest = new TransactionSignRequest(); 
    transactionSignRequest.setBlob(transactionBlob); 
    transactionSignRequest.addPrivateKey(senderPrivateKey); 
    TransactionSignResponse transactionSignResponse = sdk.getTransactionService().sign(transactionSignRequest); 
    if (transactionSignResponse.getErrorCode() == 0) { 
        signatures = transactionSignResponse.getResult().getSignatures(); 
    } else { 
        System.out.println("error: " + transactionSignResponse.getErrorDesc()); 
    } 
    return signatures; 
 } 

Return value:

 signData: 37C3EEF6FDA7CBF9AFDFAA038EE9444886F37563E5897B65F719FEB3B216E485D11A5AD31255F3DFFE533C1AA16DE9F23C73E51CF94368FDF2C5638D25D23D07 
 publicKey: b00135e99d67a4c2e10527f766e08bc6afd4420951628149042fdad6584a5321c23c716a528b

Sending the Transaction-1

Send the serialized transaction and the signature to Zetrix. The specific code for sending the transaction is as follows. The parameter transactionBlob in the example is the serialized transaction string obtained by calling seralizeTransaction, and signatures is the signature data obtained by calling signTransaction.

 public String submitTransaction(String transactionBlob, Signature[] signatures) { 
    String  hash = null; 

    // Submit transaction 
    TransactionSubmitRequest transactionSubmitRequest = new TransactionSubmitRequest(); 
    transactionSubmitRequest.setTransactionBlob(transactionBlob); 
    transactionSubmitRequest.setSignatures(signatures); 
    TransactionSubmitResponse transactionSubmitResponse = sdk.getTransactionService().submit(transactionSubmitRequest); 
    if (0 == transactionSubmitResponse.getErrorCode()) { 
        hash = transactionSubmitResponse.getResult().getHash(); 
    } else { 
        System.out.println("error: " + transactionSubmitResponse.getErrorDesc()); 
    } 
    return  hash ; 
 } 

Return value:

 hash: ac296754120911c47fb0e83d0df0c0ae82e32e9822a4a92d910886d9303b015e

Querying Whether the Transaction Was Executed Successfully-1

The following code shows how to query by calling the interface. The parameter txHash in this example is the transaction hash (the unique identifier of the transaction) obtained by calling submitTransaction.

 public int checkTransactionStatus(String txHash) {
    // Init request
    TransactionGetInfoRequest request = new TransactionGetInfoRequest();
    request.setHash(txHash);

    // Call getInfo
    TransactionGetInfoResponse response = sdk.getTransactionService().getInfo(request);
    int errorCode = response.getErrorCode();
    if (errorCode == 0){
        TransactionHistory transactionHistory = response.getResult().getTransactions()[0];
        errorCode = transactionHistory.getErrorCode();
    }

    return errorCode;
 }

Return value: 0

Error code	Description
0	Successful operation
1	Inner service defect
2	Parameters error
3	Objects already exist, such as repeated transactions
4	Objects do not exist, such as null account, transactions and blocks etc.
5	Transactions expired. It means the transaction has been removed from the buffer, but it still has probability to be executed.
7	Math calculation is overflown
20	The expression returns false. It means the TX failed to be executed currently, but it still has probability to be executed in the following blocks .
21	The syntax of the expression returns are false. It means that the TX must fail.
90	Invalid public key
91	Invalid private key
92	Invalid assets
93	The weight of the signature does not match the threshold of the operation.
94	Invalid address
97	Absent operation of TX
98	Over 100 operations in a single transaction
99	Invalid sequence or nonce of TX
100	Low reserve in the account
101	Sender and receiver accounts are the same
102	The target account already exists
103	Accounts do not exist
104	Low reserve in the account
105	Amount of assets exceeds the limitation ( int64 )
106	Insufficient initial reserve for account creation
111	Low transaction fee
114	TX buffer is full
120	Invalid weight
121	Invalid threshold
144	Invalid data version of metadata
146	Exceeds upper limitation
151	Failure in contract execution
152	Failure in syntax analysis
153	The depth of contract recursion exceeds upper limitation
154	The TX submitted from the contract exceeds upper limitation
155	Contract expired
160	Fail to insert the TX into buffer
11060	BlockNumber must be bigger than 0
11007	Failed to connect to the network
12001	Request parameter cannot be null
20000	System error

Scenario Two

This example demonstrates the contract triggering function:

The asset issuer ztxSXVGt5ujjAe4hr11VqhjWpJdKqn6QfDVUX allocates 20,000 CGO to itself via smart contract account ztxSfaizkSkNovPtVCh5X2mwtd649R6pG9YS4 on Zetrix, and transfers 10,000 CGO to account ztxSqAo6moyR5bYyTnKQXgkrzyiSBKXSwKHu4.

The implementation steps include: Creating SDK instances, Retrieving asset issuer serial number, Assembling CGO allocation and transfer operations, Serializing, Signing, Sending the transaction, and Querying execution status.

Creating SDK Instances-2

Create an instance and set the url (the IP and port of a deployed node).

 String url = "http://seed1-node.zetrix.com";
 SDK sdk = SDK.getInstance(url);

In the Zetrix network, each block is generated every 10 seconds, and each transaction requires only one confirmation to get the final state of the transaction.

Environment description:

Network Environment	IP
Experience Zetrix	seed1-node.zetrix.com

Obtaining the Serial Number of the Asset Issuer Account-2

Each Zetrix account maintains a unique serial number (also known as a nonce) that starts at 1 and increments with every successful transaction. This serial number ensures proper transaction ordering and prevents replay attacks.

 public long getAccountNonce() {
    long nonce = 0;

    // Init request
    String accountAddress = [account address of asset issuer];
    AccountGetNonceRequest request = new AccountGetNonceRequest();
    request.setAddress(accountAddress);
    
    // Call getNonce
    AccountGetNonceResponse response = sdk.getAccountService().getNonce(request);
    if (0 == response.getErrorCode()) {
        nonce = response.getResult().getNonce();
    } else {
        System.out.println("error: " + response.getErrorDesc());
    }
    return nonce;
 }

Return value:

 nonce: 8

Assembling CGO Allocation and CGO Transfer

This section contains two operations: allocating CGO and transferring CGO. The following is the sample code:

 public BaseOperation[] buildOperations() 
 { // The account address to issue apt1.0 token 
 String invokeAddress = "ztxSXVGt5ujjAe4hr11VqhjWpJdKqn6QfDVUX"; 
 // The contract address 
 String contractAddress = "ztxSfaizkSkNovPtVCh5X2mwtd649R6pG9YS4"; 
 // The destination address 
 String destAddress = "ztxSqAo6moyR5bYyTnKQXgkrzyiSBKXSwKHu4"; 
 // The amount to be assigned 
 String assignAmount = "20000"; 
 // The amount to be transfered 
 String transferAmount = "10000";


 // build assign method input 
 JSONObject assignInput = new JSONObject(); 
 assignInput.put("method", "assign"); 
 JSONObject assignParams = new JSONObject(); 
 assignParams.put("to", invokeAddress); 
 assignParams.put("value", assignAmount); 
 assignInput.put("params", assignParams); 

 // build send gas operation to assign CGO 
 ContractInvokeByGasOperation assignOperation = new ContractInvokeByGasOperation(); 
 assignOperation.setSourceAddress(invokeAddress); 
 assignOperation.setContractAddress(contractAddress); 
 assignOperation.setGasAmount(0L); 
 assignOperation.setInput(assignInput.toJSONString());

 // build transfer method input 
 JSONObject transferInput = new JSONObject(); 
 transferInput.put("method", "transfer"); 
 JSONObject transferParams = new JSONObject(); 
 transferParams.put("to", destAddress); 
 transferParams.put("value", transferAmount); 
 transferInput.put("params", transferParams);

 // build send gas operation to transfer CGO 
 ContractInvokeByGasOperation transferOperation = new ContractInvokeByGasOperation(); 
 transferOperation.setSourceAddress(invokeAddress); 
 transferOperation.setContractAddress(contractAddress); 
 transferOperation.setGasAmount(0L); 
 transferOperation.setInput(transferInput.toJSONString()); 
 BaseOperation[] operations = { assignOperation, transferOperation }; 
 return operations; }

Serializing Transactions-2

Serializing transactions for the convenience of network transmission.

Note:

• feeLimit: the maximum transaction fee that the originator of this transaction will pay for this transaction.To create a contract account and issue token operation, please fill in 0.02 Gas.

• nonce: the transaction serial number of the originator of this transaction, which is obtained by adding 1 to the nonce value of the current account.

The specific code of serializing the transaction is as follows. The parameter nonce in the example is the account serial number obtained by calling getAccountNonce, and the parameter operations is the asset issuance operation obtained by calling buildOperations. The following is the sample code for serializing the transaction:

 public String seralizeTransaction(Long nonce,  BaseOperation[] operations) { 
    String transactionBlob = null; 

    // The account address to create contract and issue token 
    String senderAddresss = "ztxSXVGt5ujjAe4hr11VqhjWpJdKqn6QfDVUX"; 
    // The gasPrice is fixed at 1000L, the unit is UGas 
    Long gasPrice = 1000L; 
    // Set up the maximum cost 10.08Gas 
    Long feeLimit = ToBaseUnit.ToUGas("0.02"); 
    // Nonce should add 1 
    nonce += 1; 
    
    // Build transaction  Blob 
    TransactionBuildBlobRequest transactionBuildBlobRequest = new TransactionBuildBlobRequest(); 
    transactionBuildBlobRequest.setSourceAddress(senderAddresss); 
    transactionBuildBlobRequest.setNonce(nonce); 
    transactionBuildBlobRequest.setFeeLimit(feeLimit); 
    transactionBuildBlobRequest.setGasPrice(gasPrice); 
    for (int i = 0; i < operations.length; i++) { 
        transactionBuildBlobRequest.addOperation(operations[i]); 
    } 
    TransactionBuildBlobResponse transactionBuildBlobResponse = sdk.getTransactionService().buildBlob(transactionBuildBlobRequest); 
    if (transactionBuildBlobResponse.getErrorCode() == 0) { 
        transactionBlob = transactionBuildBlobResponse. getResult().getTransactionBlob(); 
    } else { 
        System.out.println("error: " + transactionBuildBlobResponse.getErrorDesc()); 
    } 
    return transactionBlob; 
 } 

Return value:

 transactionBlob: 0A24627551594C745271346A336571626A564E47596B4B596F33734C4271573354514832784810091880B8D3E00320E8073AAF0108071224627551594C745271346A336571626A564E47596B4B596F33734C427157335451483278485284010A246275515A4C38706666744E416562573853626A5237376D453579747977574E3532486E751A5C7B226D6574686F64223A227472616E73666572222C22706172616D73223A7B22746F223A22627551585065546A543137336B61675A376A384E5741504A41674A43704A484664796337222C2276616C7565223A223130303030227D7D

Signing Transactions-2

All transactions need to be signed, and a transaction will not take effect until it is signed. The signature result includes signature data and a public key. The specific code for signing transactions is as follows. The parameter transactionBlob in the example is the serialized transaction string obtained by calling seralizeTransaction.

 public Signature[] signTransaction(String transactionBlob) { 
     Signature[] signatures = null; 
     // The account private key to create contract and issue token 
     String senderPrivateKey = "privbs4iBCugQeb2eiycU8RzqkPqd28eaAYrRJGwtJTG8FVHjwAyjiyC"; 

    // Sign transaction BLob 
    TransactionSignRequest transactionSignRequest = new TransactionSignRequest(); 
    transactionSignRequest.setBlob(transactionBlob); 
    transactionSignRequest.addPrivateKey(senderPrivateKey); 
    TransactionSignResponse transactionSignResponse = sdk.getTransactionService().sign(transactionSignRequest); 
    if (transactionSignResponse.getErrorCode() == 0) { 
        signatures = transactionSignResponse.getResult().getSignatures(); 
    } else { 
        System.out.println("error: " + transactionSignResponse.getErrorDesc()); 
    } 
    return signatures; 
 } 

Return value:

 signData: 244D230BD01EBE1EDFC73382ECBBF6AF7639BDC4FA95C362EC39D776FB53FEFE20D699F20EE3082F90E8E66D16484EE44D1525AD311BB333006D32AE1E2D9501
 publicKey: b00135e99d67a4c2e10527f766e08bc6afd4420951628149042fdad6584a5321c23c716a528b

Sending Transactions-2

Send the serialized transaction and signature to Zetrix. The specific code for sending transactions is as follows. The parameter transactionBlob in the example is the serialized transaction string obtained by calling seralizeTransaction, and the parameter signatures is the signature data obtained by calling signTransaction.

 public String submitTransaction(String transactionBlob, Signature[] signatures) { 
    String  hash = null; 

    // Submit transaction 
    TransactionSubmitRequest transactionSubmitRequest = new TransactionSubmitRequest(); 
    transactionSubmitRequest.setTransactionBlob(transactionBlob); 
    transactionSubmitRequest.setSignatures(signatures); 
    TransactionSubmitResponse transactionSubmitResponse = sdk.getTransactionService().submit(transactionSubmitRequest); 
    if (0 == transactionSubmitResponse.getErrorCode()) { 
        hash = transactionSubmitResponse.getResult().getHash(); 
    } else { 
        System.out.println("error: " + transactionSubmitResponse.getErrorDesc()); 
    } 
    return  hash ; 
 } 

Return value:

 hash: 7783bca41e08a14629e8ce2e12ac8580d2a287343b657f47eb7fc828ca9edb8d

Querying whether the Transaction Was Executed Successfully-2

The following code shows how to query by calling the interface. The parameter txHash in this example is the transaction hash (the unique identifier of the transaction) obtained by calling submitTransaction.

 public int checkTransactionStatus(String txHash) {
    // Init request
    TransactionGetInfoRequest request = new TransactionGetInfoRequest();
    request.setHash(txHash);

    // Call getInfo
    TransactionGetInfoResponse response = sdk.getTransactionService().getInfo(request);
    int errorCode = response.getErrorCode();
    if (errorCode == 0){
        TransactionHistory transactionHistory = response.getResult().getTransactions()[0];
        errorCode = transactionHistory.getErrorCode();
    }

    return errorCode;
 }

Return value: 0

Error code	Description
0	Successful operation
1	Inner service defect
2	Parameters error
3	Objects already exist, such as repeated transactions
4	Objects do not exist, such as null account, transactions and blocks etc.
5	Transactions expired. It means the transaction has been removed from the buffer, but it still has probability to be executed.
7	Math calculation is overflown
20	The expression returns false. It means the TX failed to be executed currently, but it still has probability to be executed in the following blocks .
21	The syntax of the expression returns are false. It means that the TX must fail.
90	Invalid public key
91	Invalid private key
92	Invalid assets
93	The weight of the signature does not match the threshold of the operation.
94	Invalid address
97	Absent operation of TX
98	Over 100 operations in a single transaction
99	Invalid sequence or nonce of TX
100	Low reserve in the account
101	Sender and receiver accounts are the same
102	The target account already exists
103	Accounts do not exist
104	Low reserve in the account
105	Amount of assets exceeds the limitation ( int64 )
106	Insufficient initial reserve for account creation
111	Low transaction fee
114	TX buffer is full
120	Invalid weight
121	Invalid threshold
144	Invalid data version of metadata
146	Exceeds upper limitation
151	Failure in contract execution
152	Failure in syntax analysis
153	The depth of contract recursion exceeds upper limitation
154	The TX submitted from the contract exceeds upper limitation
155	Contract expired
160	Fail to insert the TX into buffer
11060	BlockNumber must be bigger than 0
11007	Failed to connect to the network
12001	Request parameter cannot be null
20000	System error

Scenario Three

This example mainly implements contract query function.

Check the CGO balance of the account ztxSfaizkSkNovPtVCh5X2mwtd649R6pG9YS4 via the smart contract account ztxSqAo6moyR5bYyTnKQXgkrzyiSBKXSwKHu4 on Zetrix.

This section mainly introduces Creating SDK Instances and Querying Balance.

Creating SDK Instances-3

Create an instance and set the url (the IP and port of a deployed node).

 String url = "http://seed1-node.zetrix.com";
 SDK sdk = SDK.getInstance(url);

In the Zetrix network, each block is generated every 10 seconds, and each transaction requires only one confirmation to get the final state of the transaction. Environment description:

Network Environment	IP
Experience Zetrix	seed1-node.zetrix.com

Querying Balance

The sample code for querying the balance is as follows:

 public String queryContract() { 
    // Init variable 
    // Contract address 
    String contractAddress = "ztxSfaizkSkNovPtVCh5X2mwtd649R6pG9YS4"; 
    // TokenOwner address 
    String tokenOwner = "ztxSqAo6moyR5bYyTnKQXgkrzyiSBKXSwKHu4"; 

    // Init input 
    JSONObject input = new JSONObject(); 
    input.put("method", "balanceOf"); 
    JSONObject params = new JSONObject(); 
    params.put("address", tokenOwner); 
    input.put("params", params); 
    // Init request 
    ContractCallRequest request = new ContractCallRequest(); 
    request.setContractAddress(contractAddress); 
    request.setFeeLimit(10000000000L); 
    request.setOptType(2); 
    request.setInput(input.toJSONString()); 

    // Call call 
    String result = null; 
    ContractCallResponse response = sdk.getContractService().call(request); 
    if (response.getErrorCode() == 0) { 
        result = JSON.toJSONString(response.getResult().getQueryRets().getJSONObject(0)); 
    } else { 
        System.out.println("error: " + response.getErrorDesc()); 
    } 
    return result; 
    } 

Return value:

 {
     "result":{
         "type":"string",
         "value":"{\"balance\":\"10000\"}"
     }
 }