從帳戶更改 WEB3J 中的 ganache 所有者帳戶000記賬111或帳戶222

我正在尋找一種方法來更改 java web3j 中智能合約的所有者，就像我們在 web3 javascript 中所做的那樣，使用from：

//using account for transaction in javascript
await contract.function(param1, param2, {from: account1, value: balance});
await contract.function(param1, param2, {from: account2, value: balance});

對於 java web3j 更改交易帳戶，我找不到任何解決方案。

contract.function(param1, param2).sendAsync();

它使用預設帳戶

$$ 0 $$對於所有交易。我想更改各種交易的所有者。如何用 {from: account2, value: balance})java編寫 很高興為 web3j 更改帳戶獲得合適的答案，謝謝。

我堅持的程式碼：

public class accessControl {
   Web3j web3j = Web3j.build(new HttpService("HTTP://127.0.0.1:9545"));
   private final static String PRIVATE_KEY = "*************************";
   private final static BigInteger GAS_LIMIT = valueOf(6721975L);
   private final static BigInteger GAS_PRICE = valueOf(20000000000L);
   String ownerID = web3j.ethAccounts().send().getAccounts().get(0);
   String manufacturerID =  web3j.ethAccounts().send().getAccounts().get(1);
   String wholesalerID = web3j.ethAccounts().send().getAccounts().get(2);
   String retailerID = web3j.ethAccounts().send().getAccounts().get(3);
   private final String CONTRACT_ADDRESS = deployContract(web3j, getCredentialsFromPrivateKey());
   public static void main(String[] args) {
       try {
           new accessControl();
       } catch (Exception e) {
           e.printStackTrace();
       }
   }

   private accessControl() throws Exception {

       printWeb3Version(web3j);

       System.out.println("<-------------------ACCOUNTS----------------------->");
       System.out.println("CONTRACT ADDRESS: " + CONTRACT_ADDRESS);
       System.out.println("Contract Owner: " + ownerID);
       System.out.println("Manufacturer ID: " + manufacturerID);
       System.out.println("Wholesaler ID: " + wholesalerID);
       System.out.println("Retailer ID: " + retailerID);

       //System.out.println("DA: "+deployAddress);

       SupplyChain supplychain= loadContract(CONTRACT_ADDRESS, web3j, getCredentialsFromPrivateKey());

       supplychain.addRetailer(retailerID).send();
       supplychain.addWholesaler(wholesalerID).send();
       supplychain.addManufacturer(manufacturerID).send();

       supplychain.produceItemByManufacturer(valueOf(1), "mullick", "milk", valueOf(1)).send();
       supplychain.packageItemByManufacturer(valueOf(1)).send();
       supplychain.sellItemByManufacturer(valueOf(1), valueOf(1)).send();
       supplychain.purchaseItemByWholesaler(valueOf(1), "mr. mullick", BigInteger.valueOf(1)).send();
       supplychain.shippedItemByManufacturer(valueOf(1)).send();
       supplychain.receivedItemByWholesaler(valueOf(1)).send();
       supplychain.sellItemByWholesaler(valueOf(1), BigInteger.valueOf(1)).send();
       supplychain.purchaseItemByRetailer(valueOf(1),"mrs. mullick", BigInteger.valueOf(1)).send();
       supplychain.shippedItemByWholesaler(valueOf(1)).send();
       supplychain.receivedItemByRetailer(valueOf(1)).send();
       supplychain.fetchItemBufferOne(valueOf(1)).send();
       supplychain.fetchItemBufferTwo(valueOf(1)).send();
       supplychain.fetchWholesaler(valueOf(1)).send();
       supplychain.fetchRetailer(valueOf(1)).send();
       supplychain.fetchitemHistory(valueOf(1)).send();

   }

   private void printWeb3Version(Web3j web3j) {
       Web3ClientVersion web3ClientVersion = null;
       try {
           web3ClientVersion = web3j.web3ClientVersion().send();
       } catch (IOException e) {
           e.printStackTrace();
       }
       assert web3ClientVersion != null;
       String web3ClientVersionString = web3ClientVersion.getWeb3ClientVersion();
       System.out.println("Web3j client version: " + web3ClientVersionString);
   }

   private Credentials getCredentialsFromPrivateKey() {
       return Credentials.create(PRIVATE_KEY);
   }

   private String deployContract(Web3j web3j, Credentials credentials) throws Exception {
       return SupplyChain.deploy(web3j, credentials, GAS_PRICE, GAS_LIMIT).send().getContractAddress();
   }

   private SupplyChain loadContract(String contractAddress, Web3j web3j, Credentials credentials) throws Exception {
       return SupplyChain.load(CONTRACT_ADDRESS, web3j, credentials, GAS_PRICE, GAS_LIMIT);
   }

}

當所有者從製造商（帳戶）更改時，我需要更改 ID

$$ 1 $$)-> 批發商(帳號$$ 2 $$) -> 零售商（帳戶$$ 3 $$)，與他們的 ID 相對應，因此付款會從他們的帳戶中扣除，而不是從帳戶中扣除$$ 0 $$每次

你用

getCredentialsFromPrivateKey()

在載入合約中，將私鑰更改為賬戶擁有的私鑰。您可以為每個您想要的帳戶創建一份契約。

編輯：

private Credentials getCredentialsFromPrivateKey(String private_key) {
       return Credentials.create(private_key);
}

比

private accessControl() throws Exception {
   ...
   SupplyChain supply_chain_account0= loadContract(CONTRACT_ADDRESS, web3j, getCredentialsFromPrivateKey(account0_privatekey));
   SupplyChain supply_chain_account1= loadContract(CONTRACT_ADDRESS, web3j, getCredentialsFromPrivateKey(account1_privatekey));
   SupplyChain supply_chain_account2= loadContract(CONTRACT_ADDRESS, web3j, getCredentialsFromPrivateKey(account2_privatekey));
   ...
}

正如你所展示的，我所做的改變，

private final static String account0_privatekey = "0**********";
private final static String account1_privatekey = "1**********";
private final static String account2_privatekey = "2**********";
private final static String account3_privatekey = "3**********";
//generate contract address
private final String CONTRACT_ADDRESS = deployContract(web3j, getCredentialsFromPrivateKey(account0_privatekey));

和，

   private accessControl() throws Exception {
....
       SupplyChain supply_chain_account0= loadContract(CONTRACT_ADDRESS, web3j, getCredentialsFromPrivateKey(account1_privatekey));
       SupplyChain supply_chain_account1= loadContract(CONTRACT_ADDRESS, web3j, getCredentialsFromPrivateKey(account1_privatekey));
       SupplyChain supply_chain_account2= loadContract(CONTRACT_ADDRESS, web3j, getCredentialsFromPrivateKey(account2_privatekey));
       SupplyChain supply_chain_account3= loadContract(CONTRACT_ADDRESS, web3j, getCredentialsFromPrivateKey(account3_privatekey));

       supply_chain_account0.addRetailer(retailerID).send();
       supply_chain_account0.addWholesaler(wholesalerID).send();
       supply_chain_account0.addManufacturer(manufacturerID).send();

       supply_chain_account1.produceItemByManufacturer(valueOf(1), "mullick", "milk", valueOf(1)).send();
       supply_chain_account1.packageItemByManufacturer(valueOf(1)).send();
       supply_chain_account1.sellItemByManufacturer(valueOf(1), valueOf(1)).send();
       supply_chain_account2.purchaseItemByWholesaler(valueOf(1), "mr. mullick", valueOf(1)).send();
       supply_chain_account1.shippedItemByManufacturer(valueOf(1)).send();
       supply_chain_account2.receivedItemByWholesaler(valueOf(1)).send();
       supply_chain_account2.sellItemByWholesaler(valueOf(1), valueOf(1)).send();
       supply_chain_account3.purchaseItemByRetailer(valueOf(1),"mrs. mullick", valueOf(1)).send();
       supply_chain_account2.shippedItemByWholesaler(valueOf(1)).send();
       supply_chain_account3.receivedItemByRetailer(valueOf(1)).send();
....
}

現在它根本不執行並拋出錯誤。非常感謝 :D

引用自：https://ethereum.stackexchange.com/questions/136907