Package org.drasyl.node

Class DrasylNode

java.lang.Object
org.drasyl.node.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();

  • Field Details

    • identity

      protected final Identity identity

    • bootstrap

      protected final io.netty.bootstrap.ServerBootstrap bootstrap

  • Constructor Details

    • DrasylNode

      protected DrasylNode(Identity identity, io.netty.bootstrap.ServerBootstrap bootstrap, io.netty.channel.ChannelFuture channelFuture)

    • 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() 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

  • Method Details

    • generateIdentity

      public static Identity generateIdentity(DrasylConfig config) throws DrasylException
      Generates an identity or uses the already generated identity from the given config.
      Parameters:
      config - custom configuration used for this identity
      Returns:
      generated or already present identity
      Throws:
      DrasylException

    • 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 CompletionStage<Void> send(@NonNull String recipient, @Nullable 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.

      Parameters:
      recipient - the recipient of a message as compressed public key
      payload - the payload of a message
      Returns:
      a completion stage if the message was successfully processed, otherwise an exceptionally completion stage
      Since:
      0.1.3
      See Also:

    • send

      @NonNull public CompletionStage<Void> send(@NonNull DrasylAddress recipient, @Nullable 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.

      Parameters:
      recipient - the recipient of a message
      payload - the payload of a message
      Returns:
      a completion stage if the message was successfully processed, otherwise an exceptionally completion stage
      Since:
      0.1.3
      See Also:

    • resolve

      @NonNull public CompletionStage<io.netty.channel.Channel> resolve(@NonNull DrasylAddress address)
      Creates a future containing a Channel for communication with address.

      Note: be aware that the returned channel can be closed on inactivity according to DrasylConfig.getChannelInactivityTimeout(). A closed channel can no longer be used. However, a new channel can be created via this method.

      Parameters:
      address - peer address used for Channel creation
      Returns:
      future containing Channel for address on completion

    • resolve

      @NonNull public CompletionStage<io.netty.channel.Channel> resolve(@NonNull String address)
      Creates a future containing a Channel for communication with address.

      Note: be aware that the returned channel can be closed on inactivity according to DrasylConfig.getChannelInactivityTimeout(). A closed channel can no longer be used. However, a new channel can be created via this method.

      Parameters:
      address - peer address used for Channel creation
      Returns:
      future containing Channel for address on completion

    • shutdown

      @NonNull public CompletionStage<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 DrasylNodeSharedEventLoopGroupHolder.shutdown() method.

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

    • start

      @NonNull public CompletionStage<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

      @Nullable public io.netty.channel.ChannelPipeline pipeline()
      Returns the ChannelPipeline 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