Web3j

EthChainId chainId = web3j.ethChainId().send();
System.out.println(chainId.getChainId());

현재 체인의 chain Id를 알 수 있다.

BigInteger blockNumber = web3j.ethBlockNumber().send().getBlockNumber();
System.out.println(blockNumber);

현재 블럭의 번호를 알 수 있다.

 

String contractAddress = "${contractAddress}";

Credentials cutromerCreds = Credentials.create("${privateKey}");
TransactionManager cutomerTokenTxManager = new RawTransactionManager(
        web3j, cutromerCreds, 80001);

Event eventContract = com.event.watcher.contract.Event.load(contractAddress, web3j, cutomerTokenTxManager, new DefaultGasProvider());
try {
    eventContract.test().send();
} catch (Exception e) {
    throw new RuntimeException(e);
}

WebSocketService wss = new WebSocketService("{RPC_URL}", false);
try {
    wss.connect();
} catch (ConnectException e) {
    throw new RuntimeException(e);
}
Web3j web3jWss = Web3j.build(wss);

EthFilter ethFilter = new EthFilter(DefaultBlockParameterName.LATEST, DefaultBlockParameterName.LATEST, "{contractAddress}");
org.web3j.abi.datatypes.Event event = new org.web3j.abi.datatypes.Event("Log", Arrays.asList(new TypeReference<Address>(true) {
}, new TypeReference<Utf8String>() {
}));
String topicData = EventEncoder.encode(event);
ethFilter.addSingleTopic(topicData);
web3j.ethLogFlowable(ethFilter).subscribe(e -> {
    System.out.println(e);
}, error -> {
    System.out.println(error);
});
try {
    Thread.sleep(10000000);
} catch (InterruptedException e) {
    throw new RuntimeException(e);
}