Package org.drasyl

Class DrasylNode

java.lang.Object

org.drasyl.DrasylNode

Direct Known Subclasses:

BehavioralDrasylNode

@Beta
public abstract class DrasylNode
extends Object

Represents a node in the drasyl Overlay Network. Applications that want to run on drasyl must implement this class.

Example usage:

 DrasylNode node = new DrasylNode() {
   @Override
   public void onEvent(Event event) {
     // handle incoming events (messages) here
     System.out.println("Event received: " + event);
   }
 };
 node.start();

 // wait till NodeOnlineEvent has been received

 // send message to another node
 node.send("0229041b273dd5ee1c2bef2d77ae17dbd00d2f0a2e939e22d42ef1c4bf05147ea9", "Hello World");

 // shutdown node
 node.shutdown();
 

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	DrasylNode()	Creates a new drasyl Node.
protected	DrasylNode(DrasylConfig config)	Creates a new drasyl Node with the given config.
protected	DrasylNode(DrasylConfig config, Identity identity, PeersManager peersManager, Pipeline pipeline, PluginManager pluginManager, AtomicReference<CompletableFuture<Void>> startFuture, AtomicReference<CompletableFuture<Void>> shutdownFuture, io.reactivex.rxjava3.core.Scheduler scheduler)

Method Summary

Modifier and Type	Method	Description
static String	getVersion()	Returns the version of the node.
Identity	identity()	Returns the Identity of this node.
static void	irrevocablyTerminate()	This method stops the shared threads (EventLoopGroups), but only if none DrasylNode is using them anymore.
abstract void	onEvent(Event event)	Sends event to the application and tells it information about the local node, other peers, connections or incoming messages.
Pipeline	pipeline()	Returns the Pipeline to allow users to add own handlers.
CompletableFuture<Void>	send(String recipient, Object payload)	Sends the content of payload to the identity recipient.
CompletableFuture<Void>	send(CompressedPublicKey recipient, Object payload)	Sends the content of payload to the identity recipient.
CompletableFuture<Void>	shutdown()	Shut the drasyl node down.
CompletableFuture<Void>	start()	Start the drasyl node.

Methods inherited from class java.lang.Object

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

Constructor Detail

DrasylNode

protected DrasylNode()
              throws DrasylException

Creates a new drasyl Node. The node is only being created, it neither connects to the Overlay Network, nor can send or receive messages. To do this you have to call start().

Note: This is a blocking method, because when a node is started for the first time, its identity must be created. This can take up to a minute because of the proof of work.

Throws:

DrasylException - if identity could not be loaded or created

DrasylConfigException - if config is invalid

DrasylNode

protected DrasylNode(DrasylConfig config)
              throws DrasylException

Creates a new drasyl Node with the given config. The node is only being created, it neither connects to the Overlay * Network, nor can send or receive messages. To do this you have to call start().

Note: This is a blocking method, because when a node is started for the first time, its identity must be created. This can take up to a minute because of the proof of work.

Parameters:

config - custom configuration used for this node

Throws:

NullPointerException - if config is null

DrasylException - if identity could not be loaded or created

DrasylNode

protected DrasylNode(DrasylConfig config,
                     Identity identity,
                     PeersManager peersManager,
                     Pipeline pipeline,
                     PluginManager pluginManager,
                     AtomicReference<CompletableFuture<Void>> startFuture,
                     AtomicReference<CompletableFuture<Void>> shutdownFuture,
                     io.reactivex.rxjava3.core.Scheduler scheduler)

Method Detail

getVersion

@Nullable
public static String getVersion()

Returns the version of the node. If the version could not be read, null is returned.

Returns:

the version of the node. If the version could not be read, null is returned

irrevocablyTerminate

public static void irrevocablyTerminate()

This method stops the shared threads (EventLoopGroups), but only if none DrasylNode is using them anymore.

This operation cannot be undone. After performing this operation, no new DrasylNodes can be created!

onEvent

public abstract void onEvent(@NonNull
                             Event event)

Sends event to the application and tells it information about the local node, other peers, connections or incoming messages.

Parameters:

event - the event

send

@NonNull
public CompletableFuture<Void> send(@NonNull
                                    String recipient,
                                    Object payload)

Sends the content of payload to the identity recipient. Returns a failed future with a IllegalStateException if the message could not be sent to the recipient or a super peer. Important: Just because the future did not fail does not automatically mean that the message could be delivered. Delivery confirmations must be implemented by the application.

Note: It is possible that the passed object cannot be serialized. In this case it is not sent and the future is fulfilled with an exception. Serializable objects can be added on start via the DrasylConfig or on demand via HandlerContext.inboundSerialization() or HandlerContext.outboundSerialization().

Parameters:

recipient - the recipient of a message as compressed public key

payload - the payload of a message

Returns:

a completed future if the message was successfully processed, otherwise an exceptionally future

Since:

0.1.3-SNAPSHOT

See Also:

Handler, MessageSerializer

send

@NonNull
public CompletableFuture<Void> send(@Nullable
                                    CompressedPublicKey recipient,
                                    Object payload)

Sends the content of payload to the identity recipient. Returns a failed future with a IllegalStateException if the message could not be sent to the recipient or a super peer. Important: Just because the future did not fail does not automatically mean that the message could be delivered. Delivery confirmations must be implemented by the application.

Note: It is possible that the passed object cannot be serialized. In this case it is not sent and the future is fulfilled with an exception. Serializable objects can be added on start via the DrasylConfig or on demand via HandlerContext.inboundSerialization() or HandlerContext.outboundSerialization().

Parameters:

recipient - the recipient of a message

payload - the payload of a message

Returns:

a completed future if the message was successfully processed, otherwise an exceptionally future

Since:

0.1.3-SNAPSHOT

See Also:

Handler, MessageSerializer

shutdown

@NonNull
public CompletableFuture<Void> shutdown()

Shut the drasyl node down.

If there is a connection to a Super Peer, our node will deregister from that Super Peer.

If the local server has been started, it will now be stopped.

This method does not stop the shared threads. To kill the shared threads, you have to call the irrevocablyTerminate() method.

Returns:

this method returns a future, which complements if all shutdown steps have been completed.

start

@NonNull
public CompletableFuture<Void> start()

Start the drasyl node.

First, the identity of the node is loaded. If none exists, a new one is generated.

If activated, a local server is started. This allows other nodes to discover our node.

If a super peer has been configured, a client is started which connects to this super peer. Our node uses the Super Peer to discover and communicate with other nodes.

Returns:

this method returns a future, which complements if all components necessary for the operation have been started.

pipeline

@NonNull
public Pipeline pipeline()

Returns the Pipeline to allow users to add own handlers.

Returns:

the pipeline

identity

@NonNull
public Identity identity()

Returns the Identity of this node.

Returns:

the Identity of this node