Class EvmRpc

java.lang.Object

com.codename1.crypto.rpc.JsonRpc

com.codename1.crypto.rpc.EvmRpc

public class EvmRpc
extends JsonRpc

An Ethereum JSON-RPC client, for any EVM chain: balances, nonces, fees, gas estimates, calls, broadcasting and receipts.

EvmRpc rpc = new EvmRpc(new NetworkTransport(), "https://ethereum-sepolia-rpc.publicnode.com");
Wallet wallet = Wallet.fromMnemonic(Mnemonic.generate(128), "");
EvmAddress me = wallet.getEvmAddress(0, 0);
EvmAddress to = EvmAddress.parse("0x5aAeb6053F3E94C9b9A09f33669435E7Ef1BeAed");
UInt256 value = UInt256.parseUnits("0.01", 18);
long nonce = rpc.getTransactionCount(me, "pending");
UInt256[] fees = rpc.suggestFees();
EvmTransaction tx = EvmTransaction.eip1559(rpc.chainId(), nonce, fees[0], fees[1], 21000, to, value, null);
String hash = rpc.sendRawTransaction(wallet.signEvmTransaction(tx, Wallet.evmPath(0, 0)));

Block tags are the node's: latest, pending, safe, finalized, or a quantity.

Constructor Summary

Constructors

Constructor	Description
EvmRpc(RpcTransport transport, String url)	A client for a node.

Method Summary

Modifier and Type	Method	Description
long	blockNumber()	eth_blockNumber.
byte[]	call(EvmAddress to, byte[] data)	eth_call at the latest block.
byte[]	call(EvmAddress to, byte[] data, String block)	eth_call at a block tag, answering the returned bytes.
long	chainId()	eth_chainId.
UInt256	erc20BalanceOf(EvmAddress token, EvmAddress owner)	An ERC-20 token balance in the token's base units.
long	estimateGas(EvmAddress from, EvmAddress to, UInt256 value, byte[] data)	eth_estimateGas for a call; to is null for a contract creation.
Map<?,?>	feeHistory(int blocks, String newestBlock, double[] rewardPercentiles)	eth_feeHistory, as the node answers it.
UInt256	gasPrice()	eth_gasPrice in wei.
UInt256	getBalance(EvmAddress address)	The latest balance in wei.
UInt256	getBalance(EvmAddress address, String block)	eth_getBalance in wei at a block tag.
List<?>	getLogs(Map<String,Object> filter)	eth_getLogs for a filter object (address, topics, fromBlock, toBlock).
long	getTransactionCount(EvmAddress address, String block)	eth_getTransactionCount: the next nonce at a block tag; pending counts what is queued in the node's pool.
Map<?,?>	getTransactionReceipt(String txHash)	eth_getTransactionReceipt: the receipt, or null while the transaction is unmined.
static boolean	isSuccess(Map<?,?> receipt)	Whether a mined receipt reports success (status 1).
UInt256	maxPriorityFeePerGas()	eth_maxPriorityFeePerGas in wei.
String	sendRawTransaction(EvmTransaction signed)	eth_sendRawTransaction, answering the transaction hash.
UInt256[]	suggestFees()	EIP-1559 fees for a transaction to be included soon: {maxPriorityFeePerGas, maxFeePerGas}, the priority fee the node suggests and a fee cap of twice the latest base fee plus it, which covers six full blocks of base-fee growth.

Methods inherited from class JsonRpc

asList, asLong, asMap, asString, call, callWith, getTransport, getUrl

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

EvmRpc

public EvmRpc(RpcTransport transport,
 String url)

A client for a node.

Method Details

chainId

public long chainId()
             throws IOException

eth_chainId.

Throws:

IOException

blockNumber

public long blockNumber()
                 throws IOException

eth_blockNumber.

Throws:

IOException

getBalance

public UInt256 getBalance(EvmAddress address,
 String block)
                   throws IOException

eth_getBalance in wei at a block tag.

Throws:

IOException

getBalance

public UInt256 getBalance(EvmAddress address)
                   throws IOException

The latest balance in wei.

Throws:

IOException

getTransactionCount

public long getTransactionCount(EvmAddress address,
 String block)
                         throws IOException

eth_getTransactionCount: the next nonce at a block tag; pending counts what is queued in the node's pool.

Throws:

IOException

gasPrice

public UInt256 gasPrice()
                 throws IOException

eth_gasPrice in wei.

Throws:

IOException

maxPriorityFeePerGas

public UInt256 maxPriorityFeePerGas()
                             throws IOException

eth_maxPriorityFeePerGas in wei.

Throws:

IOException

feeHistory

public Map<?,?> feeHistory(int blocks,
 String newestBlock,
 double[] rewardPercentiles)
                    throws IOException

eth_feeHistory, as the node answers it.

Throws:

IOException

suggestFees

public UInt256[] suggestFees()
                      throws IOException

EIP-1559 fees for a transaction to be included soon: {maxPriorityFeePerGas, maxFeePerGas}, the priority fee the node suggests and a fee cap of twice the latest base fee plus it, which covers six full blocks of base-fee growth.

Throws:

IOException

estimateGas

public long estimateGas(EvmAddress from,
 EvmAddress to,
 UInt256 value,
 byte[] data)
                 throws IOException

eth_estimateGas for a call; to is null for a contract creation.

Throws:

IOException

call

public byte[] call(EvmAddress to,
 byte[] data,
 String block)
            throws IOException

eth_call at a block tag, answering the returned bytes.

Throws:

IOException

call

public byte[] call(EvmAddress to,
 byte[] data)
            throws IOException

eth_call at the latest block.

Throws:

IOException

erc20BalanceOf

public UInt256 erc20BalanceOf(EvmAddress token,
 EvmAddress owner)
                       throws IOException

An ERC-20 token balance in the token's base units.

Throws:

IOException

sendRawTransaction

public String sendRawTransaction(EvmTransaction signed)
                          throws IOException

eth_sendRawTransaction, answering the transaction hash.

Throws:

IOException

getTransactionReceipt

public Map<?,?> getTransactionReceipt(String txHash)
                               throws IOException

eth_getTransactionReceipt: the receipt, or null while the transaction is unmined.

Throws:

IOException

isSuccess

public static boolean isSuccess(Map<?,?> receipt)

Whether a mined receipt reports success (status 1).

getLogs

public List<?> getLogs(Map<String,Object> filter)
                throws IOException

eth_getLogs for a filter object (address, topics, fromBlock, toBlock).

Throws:

IOException