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這是我在我的私人網絡web3j不與合同功能一起工作?
contract AB {
/* This creates an array with all balances */
mapping (address => uint256) public balanceOf;
/* Initializes contract with initial supply tokens to the creator of the contract */
function AB() {
balanceOf[msg.sender] = 1200; // Give the creator all initial tokens
}
/* Send coins */
function transfer(address _to, uint256 _value) {
if (balanceOf[msg.sender] < _value) throw; // Check if the sender has enough
if (balanceOf[_to] + _value < balanceOf[_to]) throw; // Check for overflows
balanceOf[msg.sender] -= _value; // Subtract from the sender
balanceOf[_to] += _value; // Add the same to the recipient
}
function gettokenBalance(address to)constant returns (uint256){
return balanceOf[to];
}
}
簡單的合同我已經使用web3J生成智能合同的包裝並沒有像
public Future<Uint256> gettokenBalance(Address to) {
Function function = new Function("gettokenBalance",
Arrays.<Type>asList(to),
Arrays.<TypeReference<?>>asList(new TypeReference<Uint256>() {}));
return executeCallSingleValueReturnAsync(function);
}
功能,當我試圖訪問我的合同之類的函數
AB newAB = AB.load(contractaddress, web3j, credentials, gasprice, gaslimit);
Future<Uint256> result = newAB.gettokenBalance(new Address(address));
LOGGER.info("result:::"+result.get());
它給了我一個例外,如
java.util.concurrent.ExecutionException: java.lang.IndexOutOfBoundsException: Index: 0
at java.util.concurrent.CompletableFuture.reportGet(CompletableFuture.java:357) ~[na:1.8.0_91]
at java.util.concurrent.CompletableFuture.get(CompletableFuture.java:1895) ~[na:1.8.0_91]
at com.belrium.service.UserWalletService.check(UserWalletService.java:197) ~[classes/:na]
at com.belrium.controller.UserController.check(UserController.java:119) ~[classes/:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_91]
請幫忙。
web3j使用常規期貨,因爲生成的智能合約包裝需要與Android 1.6兼容。我希望在未來的版本中提供類似JSON-RPC調用的sync/async選項。 –
@ConorSvensson看看Kotlin可能會很有趣 - 它支持Android,它可以定位舊的Java版本。它也有非常好看的異步支持,但我還沒有嘗試過。 – Jodiug