查询余额

java使⽤web3J进⾏代币转账、余额查询

commons-io

commons-io

2.5

3j

core

3.2.0

3j

geth

3.2.0

3j

web3j-spring-boot-starter

1.6.0

publicstaticvoidmain(String[]args){

/*(,args);

("启动成功");*/

//转出地址

Stringfrom="0x9175F9EcBbddC078e40C5e037AD31F4abf36628a";

//转⼊地址

Stringto="0xa7B049d3A19796B195B0e976ec43EB7a12f07Bf9";

//转⼊数量

Stringvalue="5";

//转出地址私钥

StringprivateKey="";

//合约地址

StringcontractAddress="0x57E0297510fA155eF165646c208C495E563B3342";

//位数，根据合约⾥⾯的来

intdecimal=4;

tokenDeal(from,to,value,privateKey,contractAddress,decimal);

}

publicstaticStringtokenDeal(Stringfrom,Stringto,Stringvalue,StringprivateKey,StringcontractAddress,intdecimal){

Web3jweb3j=(newHttpService("/v3/9aa3d95b3bc440fa88ea12eaa4456161"));

try{

//转账的凭证，需要传⼊私钥

Credentialscredentials=(privateKey);

//获取交易笔数

BigIntegernonce;

EthGetTransactionCountethGetTransactionCount=TransactionCount(from,G).nd();

if(ethGetTransactionCount==null){

returnnull;

}

nonce=nsactionCount();

//⼿续费

BigIntegergasPrice;

EthGasPriceethGasPrice=Price().ndAsync().get();

if(ethGasPrice==null){

returnnull;

returnnull;

}

gasPrice=Price();

//注意⼿续费的设置，这块很容易遇到问题

BigIntegergasLimit=f(60000L);

BigIntegerval=newBigDecimal(value).multiply(newBigDecimal("10").pow(decimal)).toBigInteger();//单位换算

Functionfunction=newFunction(

"transfer",

(newAddress(to),newUint256(val)),

tonList(newTypeReference(){

}));

//创建交易对象

StringencodedFunction=(function);

RawTransactionrawTransaction=Transaction(nonce,gasPrice,gasLimit,

contractAddress,encodedFunction);

//进⾏签名操作

byte[]signMessage=ssage(rawTransaction,credentials);

StringhexValue=tring(signMessage);

//发起交易

EthSendTransactionethSendTransaction=dRawTransaction(hexValue).ndAsync().get();

Stringhash=nsactionHash();

if(hash!=null){

//执⾏业务

("执⾏成功："+hash);

returnhash;

}

}catch(Exceptionex){

//报错应进⾏错误处理

tackTrace();

}

returnnull;

}

查询余额

publicstaticvoidmain(String[]args){

//查询的钱包地址

Stringfrom="0x9175F9EcBbddC078e40C5e037AD31F4abf36628a";

//合约地址

StringcontractAddress="0x57E0297510fA155eF165646c208C495E563B3342";

//合约部署节点

Web3jweb3j=(newHttpService("/v3/9aa3d95b3bc440fa88ea12eaa4456161"));

try{

Stringcode=getERC20Balance(web3j,from,contractAddress);

("查询出来的余额："+code);

}catch(ExecutionExceptione){

tackTrace();

}catch(InterruptedExceptione){

tackTrace();

}

}

privatestaticfinalBigDecimalWEI=newBigDecimal(10000);

/**

*获取ERC-20token指定地址余额

*

*@paramaddress查询地址

*@paramcontractAddress合约地址

*@return

*@throwsExecutionException

*@throwsInterruptedException

*/

publicstaticStringgetERC20Balance(Web3jweb3j,Stringaddress,StringcontractAddress)throwsExecutionException,InterruptedException{

StringmethodName="balanceOf";

ListinputParameters=newArrayList<>();

List>outputParameters=newArrayList<>();

AddressfromAddress=newAddress(address);

(fromAddress);

TypeReferencetypeReference=newTypeReference(){

};

(typeReference);

Functionfunction=newFunction(methodName,inputParameters,outputParameters);

Stringdata=(function);

Transactiontransaction=EthCallTransaction(address,contractAddress,data);

EthCallethCall;

BigDecimalbalanceValue=;

try{

ethCall=l(transaction,).nd();

Listresults=(ue(),putParameters());

Integervalue=0;

if(results!=null&&()>0){

value=nt(f((0).getValue()));

}

balanceValue=newBigDecimal(value).divide(WEI,6,_DOWN);

}catch(IOExceptione){

tackTrace();

}

ng();

}