I have created a DMN diagram file to validate amount is less than limit or not. My use case is I don’t want to use Hardcore value.
I am trying to run the rule in spring boot. Here is the below implementation.
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>3.1.4</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>camunda-demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>camunda-demo</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>17</java.version>
</properties>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.camunda.bpm.dmn</groupId>
<artifactId>camunda-engine-dmn-bom</artifactId>
<version>7.19.0</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.camunda.bpm.dmn</groupId>
<artifactId>camunda-engine-dmn</artifactId>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
package com.example.camundademo.config;
import org.camunda.bpm.dmn.engine.DmnDecision;
import org.camunda.bpm.dmn.engine.DmnEngine;
import org.camunda.bpm.dmn.engine.DmnEngineConfiguration;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;
import java.io.IOException;
import java.io.InputStream;
@Configuration
public class DmnConfiguration {
@Bean
public DmnEngine createDmnEngine() {
DmnEngineConfiguration configuration = DmnEngineConfiguration.createDefaultDmnEngineConfiguration();
return configuration.buildEngine();
}
@Bean
public DmnDecision transactionLimit(DmnEngine dmnEngine) {
return getDmnDecision(dmnEngine, "dmn/transactionLimit.dmn", "transactionLimit");
}
private DmnDecision getDmnDecision(DmnEngine dmnEngine, String dmnFilePath, String decisionId) {
Resource resource = new ClassPathResource(dmnFilePath);
InputStream inputStream = null;
try {
inputStream = resource.getInputStream();
}
catch (IOException exception) {
exception.printStackTrace();
}
return dmnEngine.parseDecision(decisionId, inputStream);
}
}
package com.example.camundademo.service;
import org.camunda.bpm.dmn.engine.DmnDecision;
import org.camunda.bpm.dmn.engine.DmnDecisionTableResult;
import org.camunda.bpm.dmn.engine.DmnEngine;
import org.camunda.bpm.engine.variable.VariableMap;
import org.camunda.bpm.engine.variable.Variables;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Service;
@Service
public class TransactionLimitService {
private final DmnEngine engine;
private final DmnDecision decision;
public AddService(DmnEngine engine, @Qualifier("transactionLimit") DmnDecision decision) {
this.engine = engine;
this.decision = decision;
}
public int validateRule(int amount, int limit) {
VariableMap variables = Variables.putValue("amount", amount)
.putValue("limit", limit);
DmnDecisionTableResult result = engine.evaluateDecisionTable(decision, variables);
return (int) result.getSingleResult().get("transactionLimit");
}
}
When I am calling new TransactionLimitService().validateRule(amount, limit), I am getting below error:
org.camunda.bpm.dmn.feel.impl.FeelException: FEEL/SCALA-01008 Error while evaluating expression: failed to parse expression '${amount}':
can anyone suggest me how can I make those input attribute dynamic so that I can pass those value in runtime