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Aware

Introduction​

The framework currently has no DI feature, so objects cannot be injected into properties of other objects directly. But it provides an Aware mechanism to support similar capabilities.

ExternalSettingAware​

When extending custom NettyHandlers, heartbeat hooks, or user hook interfaces, you can use Aware to obtain:

  • UserSessions: manager for all connected users.
  • Server external-server info.
  • ConvenientCommunication object.
public interface ExternalSettingAware {
    void setExternalSetting(ExternalSetting setting);
}

After implementing ExternalSettingAware, the framework automatically calls setExternalSetting.

How to Use​

User online/offline hook example

  • code 7: get UserSessions.
  • code 8: get ConvenientCommunication.
public final class MyUserHook implements UserHook,
    ExternalSettingAware
{
    UserSessions<?, ?> userSessions;
    ConvenientCommunication convenientCommunication;

    @Override
    public void setExternalSetting(ExternalSetting setting) {
        this.userSessions = setting.userSessions();
        this.convenientCommunication = setting.convenientCommunication();
    }
    ...
}

Custom NettyHandler

@ChannelHandler.Sharable
public final class YourNettyHandler extends ChannelInboundHandlerAdapter
        implements ExternalSettingAware
{

    SocketUserSessions userSessions;
    ...

    @Override
    public void setExternalSetting(ExternalSetting setting) {
        this.userSessions = setting.userSessions();
        this.convenientCommunication = setting.convenientCommunication();
    }
}

Add YourNettyHandler to external server.

private static ExternalServer ofExternalServer() {
    var externalServerBuilder = MyExternalServer.builder(ExternalGlobalConfig.externalPort, ExternalJoinEnum.WEBSOCKET);

    externalServerBuilder.setMicroBootstrapFlow(new WebSocketMicroBootstrapFlow(){
        @Override
        public void pipelineCustom(PipelineContext context) {
            super.pipelineCustom(context);
            context.addLast("YourNettyHandler", new YourNettyHandler());
        }
    });

    return externalServerBuilder.build();
}
warning

You must use context.addLast to add NettyHandler, otherwise Aware cannot inject.

More Examples​

Please refer to source code of implementation classes in built-in and optional Handlers.