apache / incubator-retired-edgent-samples

Mirror of Apache Edgent (Incubating) Samples

Getting started with the Edgent samples is a great way to start using Edgent and jump-start your Edgent application development.

See IDE Quickstart if you want use an IDE instead of the command line.

Quickstart

Convenience binaries (jars) for the Edgent runtime releases are distributed to the ASF Nexus Repository and the Maven Central Repository. You don't have to manually download the Edgent jars and there is no need to download the Edgent runtime sources and build them unless you want to.

By default the samples depend on Java8. Download and install Java8 if needed.

Download the Edgent Samples

Get the Edgent Samples either by cloning or downloading the Edgent Samples GitHub repository:

git clone https://github.com/apache/incubator-edgent-samples
cd incubator-edgent-samples
git checkout develop

or to download:

• Open the Clone or download pulldown at the Edgent Samples GitHub repository
• Click on Download ZIP
• Unpack the downloaded ZIP

    unzip incubator-edgent-samples-develop.zip

Build the Samples

cd <the cloned or unpacked samples folder>
./mvnw clean package  # build for Java8

Run the HelloEdgent sample

cd topology
./run-sample.sh HelloEdgent   # prints a hello message and terminates
  Hello
  Edgent!
  ...

Overview

The Edgent samples are organized into a few categories (subdirectories) and are a collection of maven projects. They can be built using maven or other maven-integrated tooling such as Eclipse - see IDE Quickstart.

See the Samples Summary section for a list of the samples.

An Edgent application template maven project is supplied. It may be a useful starting point to clone for your application. The template has a standalone maven project pom rather than the stylized one used by the rest of the samples. See template/README.md.

See APPLICATION_DEVELOPMENT.md for general information on Edgent Application Development, Packaging and Execution.

Additional information may also be found in Getting Started https://edgent.apache.org/docs/edgent-getting-started

Setup

Once you have downloaded and unpacked the samples source bundle or cloned the the samples repository you need to download these additional development software tools.

• Java 8 - The development setup assumes Java 8

Maven is used as build tool and a maven-wrapper script (mvwn or mvnw.bat) is included.

The maven-wrapper automatically downloads and installs the correct Maven version and uses it. Besides this, there is no difference between using the mvnw command and the mvn command.

The samples use Edgent SDK jars that have been released in a maven repository such as Maven Central.

Alternatively, you can download the Edgent SDK sources and build them. See downloads for downloading the Edgent SDK sources.

Building the Edgent samples

By default Java8 class files are generated. Java7 platform class files are produced when the appropriate profile is specified.

Currently, building and running the samples for the Android platform is not supported. Many samples happen to use the DevelopmentProvider, which is not supported on the Android platform.

Build the samples

./mvnw clean package  # -Pplatform-java7 as needed

A standard jar and uber jar are created for each sample category in the sample category's target directory: <category>/target.

Building against a different Edgent runtime version

To change the version of the Edgent runtime artifacts used, edit the edgent.runtime.version property in the top level pom.xml. e.g.,

    <edgent.runtime.version>1.3.0-SNAPSHOT</edgent.runtime.version>

Note: Do NOT override the value via ./mvnw ... -Dedgent.runtime.version=<the-version>. The build will not behave as desired.

A similar declaration is present in template/pom.xml. When running get-edgent-jars.sh, specify --version=<the-version>.

Running the samples

See the README.md in each sample category directory for information on running the samples.

Samples Summary

HelloEdgent          Basic mechanics of declaring a topology and executing
                     it. Prints Hello Edgent! to standard output.
        
TempSensorApplication A basic Edgent application used by the Edgent
                     "Getting Started Guide":
                     https://edgent.apache.org/docs/edgent-getting-started.html
                     
PeriodicSource       Create a stream by polling a random number generator
                     for a new value every second and then prints out the
                     raw tuple value and a filtered and transformed stream.
                          
SensorAggregates     Demonstrates partitioned window aggregation and 
                     filtering of simulated sensors that are bursty in
                     nature, so that only intermittently is the data output
                     to standard output.
                         
File                 Use the File stream connector to write a stream of
                     tuples to files. Also watch a directory for new files
                     and create a stream of tuples from the file contents.
                         
Iotp                 Use the IBM Watson IoT Platform connector to send
                     simulated sensor readings to an IBM Watson IoT Platform
                     instance as device events. Receive device commands.
                         
JDBC                 Use the JDBC stream connector to write a stream of
                     tuples to an Apache Derby database table. Create a
                     stream of tuples by reading a table.
                         
Kafka                Use the Kafka stream connector to publish a stream of
                     tuples to a Kafka topic. Create a stream of tuples by
                     subscribing to a topic and receiving messages from it.
                         
MQTT                 Use the MQTT stream connector to publish a stream of
                     tuples to a MQTT topic. Create a stream of tuples by
                     subscribing to a topic and receiving messages from it.
                         
SensorAnalytics      Demonstrates a more complex sample that includes 
                     configuration control, a device of one or more sensors
                     and some typical analytics, use of MQTT for publishing
                     results and receiving commands, local results logging,
                     conditional stream tracing.

Many other samples are provided but have not yet been noted above. Explore!

Licensing

Apache Edgent samples are released under the Apache License Version 2.0.

Apache Edgent is an effort undergoing incubation at The Apache Software Foundation (ASF), sponsored by the Incubator PMC. Incubation is required of all newly accepted projects until a further review indicates that the infrastructure, communications, and decision making process have stabilized in a manner consistent with other successful ASF projects. While incubation status is not necessarily a reflection of the completeness or stability of the code, it does indicate that the project has yet to be fully endorsed by the ASF.