Ontology Java SDK User Guide

Version 0.7.0

Digital assets

Data structure

address base58 encoded account address
label name of account
isDefaultindicates whether the account is a default one, whose default value is set as “false”
lock indicates whether the account is locked by client users, who cannot spend in locked account
algorithm name of encryption algorithm
parameters encryption parameters
curve elliptic curve
key NEP-2 private key, whose value can be null (in case of read-only or non-standard address)
contract smart contract, whose value can be null (in case of read-only address)
extra extra information stored by client developer, whose value can be null

public class Account {
    public String label = "";
    public String address = "";
    public boolean isDefault = false;
    public boolean lock = false;
    public String algorithm = "";
    public Map parameters = new HashMap() ;
    public String key = "";
    public Contract contract = new Contract();

Digital asset account management

Create digital asset account

String url = "http://127.0.0.1:20386";
OntSdk ontSdk = OntSdk.getInstance();
ontSdk.setRpcConnection(url);
ontSdk.openWalletFile("wallet.json");
Account acct = ontSdk.getWalletMgr().createAccount("password");
//any account or identity, once created, are stored in the memory only. A write api should be invoked when writing to a wallet file.
ontSdk.getWalletMgr().writeWallet();

Remove digital asset account

ontSdk.getWalletMgr().getWallet().removeAccount(address);
//write to wallet 
ontSdk.getWalletMgr().writeWallet();

Set default digital asset account

ontSdk.getWalletMgr().getWallet().setDefaultAccount(index);
ontSdk.getWalletMgr().getWallet().setDefaultAccount("address");

Note:
index: the account with such index number is set as the default account
address: the account with such address is set as the default account —-

Native digital asset(Token)

Use SDK Method

We suggest that you use SDK method directly to deal with native digital asset.

//step1:get sdk instance
OntSdk wm = OntSdk.getInstance();
wm.setRpcConnection(url);
wm.openWalletFile("OntAssetDemo.json");
//step2:get ontAssetTx instance
ontAssetTx = ontSdk.getOntAssetTx()
//step3:transfer 
ontSdk.getOntAssetTx().sendTransferToMany("ont",info1.address,"passwordtest",new String[]{info2.address,info3.address},new long[]{100L,200L});
ontSdk.getOntAssetTx().sendTransferFromMany("ont", new String[]{info1.address, info2.address}, new String[]{"passwordtest", "passwordtest"}, info3.address, new long[]{1L, 2L});
ontSdk.getOntAssetTx().sendOngTransferFrom(info1.address,"passwordtest",info2.address,100);

Use Smart Contract

You also use smart contract to deal with native digital asset.

Ontology smart contract ABI describes the functional interface of smart contract and supports parameter transfer:

{
    "hash":"0xceab719b8baa2310f232ee0d277c061704541cfb",
    "entrypoint":"Main",
    "functions":
    [
        {
            "name":"Main",
            "parameters":
            [
                {
                    "name":"operation",
                    "type":"String"
                },
                {
                    "name":"args",
                    "type":"Array"
                }
            ],
            "returntype":"Any"
        },
        {
            "name":"Transfer",
            "parameters":
            [
                {
                    "name":"from",
                    "type":"ByteArray"
                },
                {
                    "name":"to",
                    "type":"ByteArray"
                },
                {
                    "name":"value",
                    "type":"Integer"
                }
            ],
            "returntype":"Boolean"
        },
        {
            "name":"BalanceOf",
            "parameters":
            [
                {
                    "name":"address",
                    "type":"ByteArray"
                }
            ],
            "returntype":"Integer"
        }
    ],
    "events":
    [
    ]
}

How to transfer assets by invoking Ontology asset smart contract?

//step1: read smart contract ABI
InputStream is = new FileInputStream("C:\\NeoContract1.abi.json");
byte[] bys = new byte[is.available()];
is.read(bys);
is.close();
String abi = new String(bys);

//step2：parse ABI file
AbiInfo abiinfo = JSON.parseObject(abi, AbiInfo.class);

//step3：set smart contract codeAddress
ontSdk.setCodeAddress(abiinfo.getHash());

//step4：select a function and set parameter value
AbiFunction func = abiinfo.getFunction("Transfer");
System.out.println(func.getParameters());
func.setParamsValue(param0.getBytes(),param1.getBytes(),param2.getBytes());

//setp5：invoke contract
String hash = ontSdk.getSmartcodeTx().sendInvokeSmartCodeWithSign("passwordtest",addr,func);

What would be the AbiInfo structure?

public class AbiInfo {
    public String hash;
    public String entrypoint;
    public List<AbiFunction> functions;
    public List<AbiEvent> events;
}
public class AbiFunction {
    public String name;
    public String returntype;
    public List<Parameter> parameters;
}
public class Parameter {
    public String name;
    public String type;
    public String value;
}

instruction

What is codeaddress?

codeaddress is the unique identifier of smart contract.

Why do we need to pass the account and its password when invoking?

User's signature, which is generated by the private key, is neccesary in the process of invoking a smart contract. And the private key is encrypted and stored in the wallet, which needs the password to decrypt.

What is the pre-execution of smart contract when querying the assert and how to use it?

Operations of smart contract, such as get, do not need to go through any consensus node. They read data directly from the storage of smart contract, execute at current node, and return the result. 
We can call the pre-execution interface while sending transactions.。
String result = (String) sdk.getConnectMgr().sendRawTransactionPreExec(txHex);

How to view the push results when transferring funds？

See smart contract using websocket connection call contract method，detailssmartcontract。