Helidon-POCs

Helidon SE Example (./quickstart-se)

The Helidon SE example implements the REST service using the Helidon WebServer component directly. It shows the basics of configuring the WebServer and implementing basic routing rules.

Generate The Project

mvn archetype:generate -DinteractiveMode=false
-DarchetypeGroupId=io.helidon.archetypes
-DarchetypeArtifactId=helidon-quickstart-se
-DarchetypeVersion=1.4.4
-DgroupId=io.helidon.examples
-DartifactId=quickstart-se
-Dpackage=io.helidon.examples.quickstart.se

Build the Application

cd quickstart-se

Build

mvn package

Start the application

java -jar target/quickstart-se.jar

Exercise the application

curl -X GET http://localhost:8080/greet
{"message":"Hello World!"}

curl -X GET http://localhost:8080/greet/Joe
{"message":"Hello Joe!"}

curl -X PUT -H "Content-Type: application/json" -d '{"greeting" : "Hola"}' http://localhost:8080/greet/greeting

curl -X GET http://localhost:8080/greet/Jose
{"message":"Hola Jose!"}

Try health and metrics

curl -s -X GET http://localhost:8080/health
{"outcome":"UP",...
. . .

# Prometheus Format
curl -s -X GET http://localhost:8080/metrics
# TYPE base:gc_g1_young_generation_count gauge
. . .

# JSON Format
curl -H 'Accept: application/json' -X GET http://localhost:8080/metrics
{"base":...
. . .

Helidon MP Example (./quickstart-mp)

The Helidon MP example implements the REST service using the JAX-RS support provided by the Helidon MicroProfile server.

Generate The Project

mvn archetype:generate -DinteractiveMode=false
-DarchetypeGroupId=io.helidon.archetypes
-DarchetypeArtifactId=helidon-quickstart-mp
-DarchetypeVersion=2.2.0
-DgroupId=io.helidon.examples
-DartifactId=quickstart-mp
-Dpackage=io.helidon.examples.quickstart.mp

Build the Application

cd quickstart-mp

Build

mvn package

Start the application

java -jar target/quickstart-mp.jar

Exercise the application

curl -X GET http://localhost:8080/greet
{"message":"Hello World!"}

curl -X GET http://localhost:8080/greet/Joe
{"message":"Hello Joe!"}

curl -X PUT -H "Content-Type: application/json" -d '{"greeting" : "Hola"}' http://localhost:8080/greet/greeting

curl -X GET http://localhost:8080/greet/Jose
{"message":"Hola Jose!"}

Try health and metrics

curl -s -X GET http://localhost:8080/health
{"outcome":"UP",...
. . .

# Prometheus Format
curl -s -X GET http://localhost:8080/metrics
# TYPE base:gc_g1_young_generation_count gauge
. . .

# JSON Format
curl -H 'Accept: application/json' -X GET http://localhost:8080/metrics
{"base":...
. . .

3. Helidon MP JPA (./helidon-jpa)

Adapted from the guide Using JPA in Helidon MP available here

4. Java Packaging MP (./mp-java-packaging)

Adapted from the guide Creating Docker Images available here

export JAVA_HOME=/usr/lib/jvm/default-java

mvn archetype:generate -DinteractiveMode=false \
    -DarchetypeGroupId=io.helidon.archetypes \
    -DarchetypeArtifactId=helidon-quickstart-mp \
    -DarchetypeVersion=1.4.1 \
    -DgroupId=io.helidon.examples \
    -DartifactId=mp-java-packaging \
    -Dpackage=io.helidon.mp.javapackaging