DMN + Spring Boot example

Description

A simple DMN service to evaluate a traffic violation and a model with input constraints.

The org.kie.dmn.runtime.typecheck=true property is used to enable type and value check.

Installing and Running

Prerequisites

You will need:

• Java 11+ installed
• Environment variable JAVA_HOME set accordingly
• Maven 3.8.6+ installed

Compile and Run

mvn clean compile spring-boot:run

Package and Run

mvn clean package
java -jar ./target/dmn-springboot-example.jar

Test DMN Model using Maven

Validate the functionality of DMN models before deploying them into a production environment by defining test scenarios in Test Scenario Editor.

To define test scenarios you need to create a .scesim file inside your project and link it to the DMN model you want to be tested. Run all Test Scenarios, executing:

mvn clean test

See results in surefire test report target/surefire-reports

OpenAPI (Swagger) documentation

Specification at swagger.io

The Swagger page shows all the available endpoints, and it could be used to test them. You can take a look at the OpenAPI definition - automatically generated and included in this service - to determine all available operations exposed by this service. For easy readability you can visualize the OpenAPI definition file using a UI tool like for example available Swagger Editor.

Example Usage

Once the service is up and running, you can use the following example to interact with the service.

POST /Traffic Violation

Returns penalty information from the given inputs -- driver and violation: Given inputs:

{
    "Driver":{ "Points":2 },
    "Violation":{
        "Type":"speed",
        "Actual Speed":120,
        "Speed Limit":100
    }
}

Curl command (using the JSON object above):

curl -X POST -H 'Accept: application/json' -H 'Content-Type: application/json' -d '{"Driver":{"Points":2},"Violation":{"Type":"speed","Actual Speed":120,"Speed Limit":100}}' http://localhost:8080/Traffic%20Violation

As response, penalty information is returned.

Example response:

{
  "Violation":{
    "Type":"speed",
    "Speed Limit":100,
    "Actual Speed":120
  },
  "Driver":{
    "Points":2
  },
  "Fine":{
    "Points":3,
    "Amount":500
  },
  "Should the driver be suspended?":"No"
}

POST /AllowedValuesChecksInsideCollection

Valid interests for the model are: Golf, Computer, Hockey, Jogging

Given valid input:

{
 "p1": {
  "Name": "Joe",
  "Interests": [
   "Golf"
  ]
 }
}

Curl command (using the JSON object above):

curl -X POST -H 'Accept: application/json' -H 'Content-Type: application/json' -d '{"p1": {"Name":"Joe","Interests":["Golf"]}}' http://localhost:8080/AllowedValuesChecksInsideCollection

As response, interests information is returned.

Example response:

{
 "p1": {
  "Interests": [
   "Golf"
  ],
  "Name": "Joe"
 },
 "MyDecision": "The Person Joe likes 1 thing(s)."
}

With invalid value

{
 "p1": {
  "Name": "Joe",
  "Interests": [
   "Dancing"
  ]
 }
}

Curl command (using the JSON object above):

curl -X POST -H 'Accept: application/json' -H 'Content-Type: application/json' -d '{"p1": {"Name":"Joe","Interests":["Dancing"]}}' http://localhost:8080/AllowedValuesChecksInsideCollection

As response, error information is returned.

Example response:

{
 "namespace": "http://www.trisotech.com/definitions/_238bd96d-47cd-4746-831b-504f3e77b442",
 "modelName": "AllowedValuesChecksInsideCollection",
 "dmnContext": {
  "p1": {
   "Interests": [
    "Dancing"
   ],
   "Name": "Joe"
  }
 },
 "messages": [
  {
   "severity": "ERROR",
   "message": "Error while evaluating node 'MyDecision' for dependency 'p1': the dependency value '{Interests=[Dancing], Name=Joe}' is not allowed by the declared type (DMNType{ http://www.trisotech.com/definitions/_238bd96d-47cd-4746-831b-504f3e77b442 : Person })",
   "messageType": "ERROR_EVAL_NODE",
   "sourceId": "_27453770-68e3-48da-8605-d33a653c09ef",
   "level": "ERROR"
  }
 ],
 "decisionResults": [
  {
   "decisionId": "_ed3b9794-9306-4b6a-b4f9-5486be3c5515",
   "decisionName": "MyDecision",
   "result": null,
   "messages": [
    {
     "severity": "ERROR",
     "message": "Error while evaluating node 'MyDecision' for dependency 'p1': the dependency value '{Interests=[Dancing], Name=Joe}' is not allowed by the declared type (DMNType{ http://www.trisotech.com/definitions/_238bd96d-47cd-4746-831b-504f3e77b442 : Person })",
     "messageType": "ERROR_EVAL_NODE",
     "sourceId": "_27453770-68e3-48da-8605-d33a653c09ef",
     "level": "ERROR"
    }
   ],
   "evaluationStatus": "SKIPPED"
  }
 ]
}

Developer notes

In order to have the DMN generated resources properly scanned by Spring Boot, please ensure the DMN model namespaces is included in the String application configuration.

The generated classes must be included in the annotation definitions of the main Application class:

@SpringBootApplication(scanBasePackages={"org.kie.kogito.**", "org.kie.kogito.app.**", "http*"})
public class KogitoSpringbootApplication {

    public static void main(String[] args) {
        SpringApplication.run(KogitoSpringbootApplication.class, args);
    }
}