org.hyperledger.fabric.gateway

Interface Network

public interface Network

A Network object represents the set of peers in a Fabric network (channel). Applications should get a Network instance from a Gateway using the Gateway.getNetwork(String) method.

The Network object provides the ability for applications to:

• Obtain a specific smart contract deployed to the network using getContract(String), in order to submit and evaluate transactions for that smart contract.
• Listen to new block events using addBlockListener(Consumer).
• Replay previous block events using addBlockListener(long, Consumer).

See Also:

Developing Fabric Applications - Network Channel

Method Summary

Modifier and Type	Method and Description
Consumer<org.hyperledger.fabric.sdk.BlockEvent>	addBlockListener(Checkpointer checkpointer, Consumer<org.hyperledger.fabric.sdk.BlockEvent> listener) Add a listener to receive block events from the network with checkpointing.
Consumer<org.hyperledger.fabric.sdk.BlockEvent>	addBlockListener(Consumer<org.hyperledger.fabric.sdk.BlockEvent> listener) Add a listener to receive block events from the network.
Consumer<org.hyperledger.fabric.sdk.BlockEvent>	addBlockListener(long startBlock, Consumer<org.hyperledger.fabric.sdk.BlockEvent> listener) Add a listener to replay block events from the network.
CommitListener	addCommitListener(CommitListener listener, Collection<org.hyperledger.fabric.sdk.Peer> peers, String transactionId) Add a listener to receive transaction commit and peer disconnect events for a set of peers.
org.hyperledger.fabric.sdk.Channel	getChannel() Get the low-level chanel object associated with this network.
Contract	getContract(String chaincodeId) Get an instance of a contract on the current network.
Contract	getContract(String chaincodeId, String name) Get an instance of a contract on the current network.
Gateway	getGateway() Get a reference to the owning Gateway connection.
void	removeBlockListener(Consumer<org.hyperledger.fabric.sdk.BlockEvent> listener) Removes a previously added block listener.
void	removeCommitListener(CommitListener listener) Removes a previously added transaction commit listener.

Method Detail

getContract

Contract getContract(String chaincodeId)

Get an instance of a contract on the current network.

Parameters:

chaincodeId - The name of the chaincode that implements the smart contract.

Returns:

The contract object.

getContract

Contract getContract(String chaincodeId,
                     String name)

Get an instance of a contract on the current network. If the chaincode instance contains more than one smart contract class (available using the latest chaincode programming model), then an individual class can be selected.

Parameters:

chaincodeId - The name of the chaincode that implements the smart contract.

name - The class name of the smart contract within the chaincode.

Returns:

The contract object.

getGateway

Gateway getGateway()

Get a reference to the owning Gateway connection.

Returns:

The owning gateway.

getChannel

org.hyperledger.fabric.sdk.Channel getChannel()

Get the low-level chanel object associated with this network.

Returns:

A channel.

addBlockListener

Consumer<org.hyperledger.fabric.sdk.BlockEvent> addBlockListener(Consumer<org.hyperledger.fabric.sdk.BlockEvent> listener)

Add a listener to receive block events from the network. Events are received in order and without duplication.

Parameters:

listener - A block listener.

Returns:

The block listener argument.

addBlockListener

Consumer<org.hyperledger.fabric.sdk.BlockEvent> addBlockListener(Checkpointer checkpointer,
                                                                 Consumer<org.hyperledger.fabric.sdk.BlockEvent> listener)
                                                          throws IOException

Add a listener to receive block events from the network with checkpointing. Re-adding a listener with the same checkpointer on subsequent application invocations will resume listening from the previous block position. Events are received in order and without duplication.

Parameters:

checkpointer - Checkpointer to persist block position.

listener - A block listener.

Returns:

The block listener argument.

Throws:

IOException - if an error occurs establishing checkpointing.

GatewayRuntimeException - if an underlying infrastructure failure occurs.

addBlockListener

Consumer<org.hyperledger.fabric.sdk.BlockEvent> addBlockListener(long startBlock,
                                                                 Consumer<org.hyperledger.fabric.sdk.BlockEvent> listener)

Add a listener to replay block events from the network. Events are received in order and without duplication.

Parameters:

startBlock - The number of the block from which events should be replayed.

listener - A block listener.

Returns:

The block listener argument.

Throws:

GatewayRuntimeException - if an underlying infrastructure failure occurs.

removeBlockListener

void removeBlockListener(Consumer<org.hyperledger.fabric.sdk.BlockEvent> listener)

Removes a previously added block listener.

Parameters:

listener - A block listener.

addCommitListener

CommitListener addCommitListener(CommitListener listener,
                                 Collection<org.hyperledger.fabric.sdk.Peer> peers,
                                 String transactionId)

Add a listener to receive transaction commit and peer disconnect events for a set of peers.

Parameters:

listener - A transaction commit listener.

peers - The peers from which to receive events.

transactionId - A transaction ID.

Returns:

The transaction commit listener argument.

removeCommitListener

void removeCommitListener(CommitListener listener)

Removes a previously added transaction commit listener.

Parameters:

listener - A block listener.