Lightstreamer - Round-Trip Demo - Java Adapter

This project shows the Round-Trip Demo Data and Metadata Adapters and how they can be plugged into Lightstreamer Server and used to feed the Lightstreamer - Round-Trip Demo - HTML Client front-end. The Round-Trip Demo is a simple broadcast messages application based on Lightstreamer.

Details

The project is comprised of source code and a deployment example.

Dig the Code

The source code is divided into two folders.

Round-Trip Data Adapter

Contains the source code for the Round-Trip Data Adapter. This Adapter broadcasts to all connected users the messages received from the Metadata Adapter for the five defined items in real-time.

Metadata Adapter

Contains the source code for a Metadata Adapter to be associated with the Round-Trip Demo Data Adapter. This Metadata Adapter inherits from the reusable LiteralBasedProvider in Lightstreamer Java In-Process Adapter SDK and it plays the extra-role of receiving messages from the clients and forwarding them to the Data Adapter.
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.

See the source code comments for further details.

The Adapter Set Configuration

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

The adapters.xml file for the Round-Trip Demo, should look like:

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

<metadata_adapter_initialised_first>Y</metadata_adapter_initialised_first>

  <metadata_provider>

	  <adapter_class>com.lightstreamer.examples.roundtrip_demo.adapters.RoundTripMetadataAdapter</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="prefilter_frequency">5</param>
	  <param name="allowed_users">user123,user456</param>
	  <param name="distinct_snapshot_length">30</param>
	  -->

	  <!-- Optional, managed by the inherited LiteralBasedProvider.
		   See LiteralBasedProvider javadoc. -->
	  <param name="item_family_1">roundtrip\d{1,2}</param>
	  <param name="modes_for_item_family_1">MERGE</param>

  </metadata_provider>


  <data_provider name="ROUNDTRIP_ADAPTER">

	  <adapter_class>com.lightstreamer.examples.roundtrip_demo.adapters.RoundTripDataAdapter</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 the Round-Trip 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.
• Make sure that Lightstreamer Server is not running.
• Get the deploy.zip file of the latest release, unzip it, and copy the RoundTripDemo folder into the adapters folder of your Lightstreamer Server installation.
• [Optional] Customize the logging settings in log4j configuration file: RoundTripDemo/classes/log4j2.xml.
• Launch Lightstreamer Server.
• Test the Adapter, launching the Lightstreamer - Round-Trip Demo - HTML Client listed in Clients Using This Adapter.

Build

To build your own version of roundtrip-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 - Round-Trip Demo - HTML Client
• Lightstreamer - Basic Stock-List and Round-trip Demo - Java ME 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 7.3 to 7.4, 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.