Lightstreamer / Lightstreamer-example-Messenger-adapter-java

This project shows the Messenger Demo Data and Metadata Adapters and how they can be plugged into Lightstreamer Server

Lightstreamer - Basic Messenger Demo - Java Adapter

The Basic Messenger Demo is a very simple instant messenger application based on Lightstreamer for its real-time communication needs.

This project shows the Data Adapter and Metadata Adapters for the Basic Messenger Demo and how they can be plugged into Lightstreamer Server.

As an example of a client using this adapter, you may refer to the Lightstreamer - Basic Messenger Demo - HTML Client and view the corresponding Live Demo.

Details

Dig The Code

The project is comprised of source code and a deployment example. The source code is divided into two folders.

Messenger DataAdapter

Contains the source code for the Messenger Data Adapter. This Data Adapter provides a basic round-trip support for client-originated messages to client-specific Items.

Messenger MetadataAdapter

Contains the source code for a Metadata Adapter to be associated with the Messenger Demo Data Adapter. This Metadata Adapter inherits from the reusable LiteralBasedProvider in Lightstreamer Java In-Process Adapter SDK and just adds a simple support for message submission.
It should not be used as a reference for a real case of client-originated message handling, as no guaranteed delivery and no clustering support is shown.

The Adapter Set Configuration

This Adapter Set Name is configured and will be referenced by the clients as MESSENGER.

The adapters.xml file for this demo should look like:

<?xml version="1.0"?>
  <adapters_conf id="MESSENGER">

    <metadata_adapter_initialised_first>Y</metadata_adapter_initialised_first>
  
      <metadata_provider>

          <adapter_class>com.lightstreamer.examples.messenger_demo.adapters.IMMetadataAdapter</adapter_class>

          <!-- Optional, managed by the inherited LiteralBasedProvider.
               See LiteralBasedProvider javadoc. -->
          <!--
          <param name="max_bandwidth">40</param>
          <param name="max_frequency">3</param>
          <param name="buffer_size">30</param>
          <param name="distinct_snapshot_length">10</param>
          <param name="prefilter_frequency">5</param>
          <param name="allowed_users">user123,user456</param>
          -->
        
          <!-- Optional, managed by the inherited LiteralBasedProvider.
               See LiteralBasedProvider javadoc. -->
          <param name="item_family_1">buddy_list</param>
          <param name="modes_for_item_family_1">COMMAND</param>
          <!-- provided by the Data Provider for each client session -->
          <param name="item_family_2">im_.*</param>
          <param name="modes_for_item_family_2">DISTINCT</param>
        
      </metadata_provider>

      <data_provider name="SIMPLE_MESSENGER">

          <adapter_class>com.lightstreamer.examples.messenger_demo.adapters.IMDataAdapter</adapter_class>

      </data_provider>

  </adapters_conf>

NOTE: not all configuration options of an Adapter Set are exposed by the file suggested above. You can easily expand your configurations using the generic template, see the Java In-Process Adapter Interface Project for details.

Please refer here for more details about Lightstreamer Adapters.

Install

If you want to install a version of this demo in your local Lightstreamer Server, follow these steps:

• Download Lightstreamer Server (Lightstreamer Server comes with a free non-expiring demo license for 20 connected users) from Lightstreamer Download page, and install it, as explained in the GETTING_STARTED.TXT file in the installation home directory.
• Get the deploy.zip file of the latest release, unzip it, and copy the just unzipped MessengerDemo folder into the adapters folder of your Lightstreamer Server installation.
• [Optional] Customize the logging settings in log4j configuration file: MessengerDemo/classes/log4j2.xml.
• Launch Lightstreamer Server.
• Test the Adapter, launching one of the Clients Using This Adapter.

Build

To build your own version of messenger--adapter-java-x.y.z.jar instead of using the one provided in the deploy.zip file from the Install section above, you have two options: either use Maven (or other build tools) to take care of dependencies and building (recommended) or gather the necessary jars yourself and build it manually. For the sake of simplicity only the Maven case is detailed here.

Maven

You can easily build and run this application using Maven through the pom.xml file located in the root folder of this project. As an alternative, you can use an alternative build tool (e.g. Gradle, Ivy, etc.) by converting the provided pom.xml file.

Assuming Maven is installed and available in your path you can build the demo by running

 mvn install dependency:copy-dependencies 

See Also

Clients Using This Adapter

• Lightstreamer - Basic Messenger Demo - HTML Client

Related Projects

• LiteralBasedProvider Metadata Adapter
• Lightstreamer - Basic Chat Demo - Java Adapter
• Lightstreamer - Basic Chat Demo - HTML Client

Lightstreamer Compatibility Notes

• Compatible with Lightstreamer SDK for Java In-Process Adapters since version 8.0.
• For a version of this example compatible with Lightstreamer SDK for Java Adapters versions 7.4.x, please refer to this tag.
• For a version of this example compatible with Lightstreamer SDK for Java Adapters versions 7.0 to 7.3, please refer to this tag.
• For a version of this example compatible with Lightstreamer SDK for Java Adapters version 6.0, please refer to this tag.
• For a version of this example compatible with Lightstreamer SDK for Java Adapters version 5.1, please refer to this tag.