Query Api¶

QueryApi provides high-level api for querying state from aergo node. It doesn’t need unlocked account.

Get Account State¶

Get account state.

// get account state
AccountAddress accountAddress = AccountAddress
    .of("AmNrsAqkXhQfE6sGxTutQkf9ekaYowaJFLekEm8qvDr1RB1AnsiM");
AccountState state = walletApi.with(client).query()
    .getAccountState(accountAddress);
System.out.println("Account state: " + state);

Get Name Owner¶

Get name owner.

At current block.

// get name owner
Name name = Name.of("namenamename");
AccountAddress nameOwner = walletApi.with(client).query().getNameOwner(name);
System.out.println("Name owner: " + nameOwner);

At specific block.

// get name owner at block 10
Name name = Name.of("namenamename");
AccountAddress nameOwner = walletApi.with(client).query().getNameOwner(name, 10);
System.out.println("Name owner: " + nameOwner);

Get Stake Info¶

Get stake info of an account.

// get stake info
AccountAddress accountAddress = AccountAddress
    .of("AmNrsAqkXhQfE6sGxTutQkf9ekaYowaJFLekEm8qvDr1RB1AnsiM");
StakeInfo stakeInfo = walletApi.with(client).query().getStakeInfo(accountAddress);
System.out.println("Stake info: " + stakeInfo);

List Elected Bps¶

Get elected block producers.

// list elected bps
List<ElectedCandidate> candidates = walletApi.with(client).query().listElectedBps(23);
System.out.println("Elected bps: " + candidates);

List Elected¶

Get elected candidates for vote id.

// list elected for "voteBP"
List<ElectedCandidate> candidates = walletApi.with(client).query()
    .listElected("voteBP", 23);
System.out.println("Elected candidates: " + candidates);

Get Vote Info¶

Get vote info of an account.

// get vote info
AccountAddress accountAddress = AccountAddress
    .of("AmNrsAqkXhQfE6sGxTutQkf9ekaYowaJFLekEm8qvDr1RB1AnsiM");
AccountTotalVote accountTotalVote = walletApi.with(client).query().getVotesOf(accountAddress);
System.out.println("Account total vote: " + accountTotalVote);

Get Best Block Hash¶

Get best block hash.

// get best block hash
BlockHash blockHash = walletApi.with(client).query().getBestBlockHash();
System.out.println("Best block hash: " + blockHash);

Get Best Block Height¶

Get best block height.

// get best block hash
long blockHeight = walletApi.with(client).query().getBestBlockHeight();
System.out.println("Best block height: " + blockHeight);

Get Chain Id Hash¶

Get chain id hash of blockchain.

// get chain id hash
ChainIdHash chainIdHash = walletApi.with(client).query().getChainIdHash();
System.out.println("Chain id hash: " + chainIdHash);

Get Blockchain Status¶

Get blockchain status.

// get blockchain status
BlockchainStatus blockchainStatus = walletApi.with(client).query().getBlockchainStatus();
System.out.println("Blockchain status: " + blockchainStatus);

Get Chain Info¶

Get chain info of current node.

// get chain info
ChainInfo chainInfo = walletApi.with(client).query().getChainInfo();
System.out.println("ChainInfo: " + chainInfo);

Get Chain Stats¶

Get chain statistics of current node.

// get chain stats
ChainStats chainStats = walletApi.with(client).query().getChainStats();
System.out.println("ChainStats: " + chainStats);

List Peers¶

List peers of current node.

Filtering hidden peers and itself.

// list peers
List<Peer> peers = walletApi.with(client).query().listPeers();
System.out.println("Peers: " + peers);

Not filtering hidden peers and itself.

// list peers
List<Peer> peers = walletApi.with(client).query().listPeers(true, true);
System.out.println("Peers: " + peers);

List Peer Metrics¶

List peers metrics of current node.

// list peer metrics
List<PeerMetric> peerMetrics = walletApi.with(client).query().listPeerMetrics();
System.out.println("Peer metrics: " + peerMetrics);

Get Server Info¶

Get server info of current node. Category is not implemented yet.

// get server info
List<String> categories = emptyList();
ServerInfo serverInfo = walletApi.with(client).query().getServerInfo(categories);
System.out.println("Server info: " + serverInfo);

Get Node Status¶

Get node status of current node.

// get node status
NodeStatus nodeStatus = walletApi.with(client).query().getNodeStatus();
System.out.println("Node status: " + nodeStatus);

Get Block Metadata¶

Get block metadata. It returns null if no corresponding one.

By hash.

// get block metadata
BlockHash blockHash = BlockHash.of("DN9TvryaThbJneSpzaXp5ZsS4gE3UMzKfaXC4x8L5qR1");
BlockMetadata blockMetadata = walletApi.with(client).query().getBlockMetadata(blockHash);
System.out.println("Block metadata by hash: " + blockMetadata);

By height.

// get block metadata
long height = 27_066_653L;
BlockMetadata blockMetadata = walletApi.with(client).query().getBlockMetadata(height);
System.out.println("Block metadata by height: " + blockMetadata);

List Block Metadata¶

Get block metadatas. Size maximum is 1000.

By hash.

// block metadatas by from hash to previous 100 block
BlockHash blockHash = BlockHash.of("DN9TvryaThbJneSpzaXp5ZsS4gE3UMzKfaXC4x8L5qR1");
List<BlockMetadata> blockMetadatas = walletApi.with(client).query()
    .listBlockMetadatas(blockHash, 100);
System.out.println("Block metadatas by hash: " + blockMetadatas);

By height.

// block metadatas by from height to previous 100 block
long height = 27_066_653L;
List<BlockMetadata> blockMetadatas = walletApi.with(client).query()
    .listBlockMetadatas(height, 100);
System.out.println("Block metadatas by height: " + blockMetadatas);

Get Block¶

Get block. It returns null if no corresponding one.

By hash.

// get block by hash
BlockHash blockHash = BlockHash.of("DN9TvryaThbJneSpzaXp5ZsS4gE3UMzKfaXC4x8L5qR1");
Block block = walletApi.with(client).query().getBlock(blockHash);
System.out.println("Block by hash: " + block);

By height.

// get block by height
long height = 27_066_653L;
Block block = walletApi.with(client).query().getBlock(height);
System.out.println("Block by hash: " + block);

Block Metadata Subscription¶

Subscribe new generated block metadata.

// make a subscription
Subscription<BlockMetadata> metadataSubscription = walletApi.with(client).query()
    .subscribeBlockMetadata(new StreamObserver<BlockMetadata>() {
      @Override
      public void onNext(BlockMetadata value) {
        System.out.println("Next block metadata: " + value);
      }

      @Override
      public void onError(Throwable t) {

      }

      @Override
      public void onCompleted() {
      }
    });

// wait for a while
Thread.sleep(2000L);

// unsubscribe it
metadataSubscription.unsubscribe();

Block Subscription¶

Subscribe new generated block.

// make a subscription
Subscription<Block> subscription = walletApi.with(client).query()
    .subscribeBlock(new StreamObserver<Block>() {
      @Override
      public void onNext(Block value) {
        System.out.println("Next block: " + value);
      }

      @Override
      public void onError(Throwable t) {
      }

      @Override
      public void onCompleted() {
      }
    });

// wait for a while
Thread.sleep(2000L);

// unsubscribe it
subscription.unsubscribe();

Get Transaction¶

Get transaction info. It returns null if no corresponding one.

// get transaction
TxHash txHash = TxHash.of("39vLyMqsg1mTT9mF5NbADgNB2YUiRVsT6SUkDujBZme8");
Transaction transaction = walletApi.with(client).query().getTransaction(txHash);
System.out.println("Transaction: " + transaction);

Get Transaction Receipt¶

Get receipt of transaction. It returns null if no corresponding one.

// get tx receipt
TxHash txHash = TxHash.of("39vLyMqsg1mTT9mF5NbADgNB2YUiRVsT6SUkDujBZme8");
TxReceipt txReceipt = walletApi.with(client).query().getTxReceipt(txHash);
System.out.println("Transaction receipt: " + txReceipt);

Get Contract Tx Receipt¶

Get contract tx receipt. It returns null if no corresponding one.

// get contract tx receipt
TxHash txHash = TxHash.of("EGXNDgjY2vQ6uuP3UF3dNXud54dF4FNVY181kaeQ26H9");
ContractTxReceipt contractTxReceipt = walletApi.with(client).query()
    .getContractTxReceipt(txHash);
System.out.println("Contract tx receipt: " + contractTxReceipt);

Get Contract Interface¶

Get contract interface. It returns null if no corresponding one.

// get contract interface
ContractAddress contractAddress = ContractAddress
    .of("AmNrsAqkXhQfE6sGxTutQkf9ekaYowaJFLekEm8qvDr1RB1AnsiM");
ContractInterface contractInterface = walletApi.with(client).query()
    .getContractInterface(contractAddress);
System.out.println("ContractInterface: " + contractInterface);

Query Contract¶

Get state of contract. It can be binded to an java bean. For more about making contract invocation, see ContractInvocation.

// make a contract invocation
ContractInterface contractInterface = contractInterfaceKeep;
ContractInvocation query = contractInterface.newInvocationBuilder()
    .function("get")
    .args("key")
    .build();

// query contract
ContractResult queryResult = client.getContractOperation().query(query);
Data data = queryResult.bind(Data.class);
System.out.println("Raw contract result: " + queryResult);
System.out.println("Binded data: " + data);

List Event¶

Get event infos at some block. For more about making event filter, see EventFilter.

// list events with a filter
ContractAddress contractAddress = contractAddressKeep;
EventFilter eventFilter = EventFilter.newBuilder(contractAddress)
    .eventName("set")
    .args("key")
    .recentBlockCount(1000)
    .build();
List<Event> events = client.getContractOperation().listEvents(eventFilter);
System.out.println("Events: " + events);

Event Subscription¶

Subscribe new generated event of specific contract. For more about making event filter, see EventFilter.

// subscribe event
ContractAddress contractAddress = ContractAddress
    .of("AmNrsAqkXhQfE6sGxTutQkf9ekaYowaJFLekEm8qvDr1RB1AnsiM");
EventFilter eventFilter = EventFilter.newBuilder(contractAddress)
    .recentBlockCount(1000)
    .build();
Subscription<Event> subscription = client.getContractOperation()
    .subscribeEvent(eventFilter, new StreamObserver<Event>() {
      @Override
      public void onNext(Event value) {
        System.out.println("Next event: " + value);
      }

      @Override
      public void onError(Throwable t) {
      }

      @Override
      public void onCompleted() {
      }
    });

Thread.sleep(2200L);

// unsubscribe event
subscription.unsubscribe();