How to Build and Run a Command

4. Implementation

For the demonstration of the single steps in this tutorial the IDE IntelliJ is used.

First open your selected IDE and create a new Gradle project with the following configuration:

By adding a sample code you will automatically get the desired folder structure

Figure 1. Gradle-Project Configuration

Then replace the build.gradle file with the following code fragment:

build.gradle

plugins {
    id 'java-library'
    id 'maven-publish'
}
ext {
    version = '1.0.0'
    pakVersion = '1.5.14'
}
allprojects {
    project.description = 'Example Commands for PAK'
    project.group = 'org.example'
    project.version = rootProject.ext.version

    repositories {
        mavenCentral()
        maven {
            name = 'pak-explorer-maven'
            url 'https://pak.asap.de/nexus/repository/pak-explorer-maven/'
        }
    }
}

subprojects {
    apply plugin: 'java-library'
    apply plugin: 'maven-publish'

    compileJava.options.encoding = 'UTF-8'
    sourceCompatibility = 11
    targetCompatibility = 11

    javadoc {
        source = sourceSets.main.allJava
    }
}
dependencies{
    // Dependencies provided by PAK
    annotationProcessor "de.asap.pak.jlcint:jlcint-processor:${pakVersion}"

    implementation "de.asap.pak.jlcint:jlcint-commandapi:${pakVersion}"
    implementation "de.asap.pak.core:pak-common:${pakVersion}"

    // Extern dependencies
    implementation 'org.slf4j:slf4j-api:1.7.25'
}
compileJava {
    options.compilerArgs.add("-Aversion=$project.version")
    options.compilerArgs.add("-Agroup=$project.group")
    options.compilerArgs.add("-Aname=$project.name")
}
javadoc {
    source = sourceSets.main.allJava
    options.tags = [
            'workflowDocu:cm:Workflow Developer Documentation:'
    ]
}

task metaJar(type: Jar) {
    archiveClassifier = 'pakmeta'
    from sourceSets.main.output
    include 'meta/**'
    include 'entities/**'
    from sourceSets.main.java
    include 'icon/**'
}

publishing () {
    publications {
        local(MavenPublication) {
            artifactId = project.name
            from components.java
        }
    }
}

You can verify the successful loading of build.gradle using the Gradle toolbar on the right side. This should look like this:

Figure 2. Gradle-Toolbar

Now we come to the coding of the HelloWorld command. For that you just have to replace the main class with the following class:

HelloWorld.java

package org.example;

import de.asap.pak.jlcint.commandapi.CommandGroup;
import de.asap.pak.jlcint.commandapi.FieldScope;
import de.asap.pak.jlcint.commandapi.JavaCommand;
import de.asap.pak.jlcint.commandapi.Persistent;
import de.asap.pak.jlcint.commandapi.Run;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Sample implementation for a example command that input name and returns a simple output.
 *
 * The @JavaCommand annotation is necessary for the annotation processor to recognize this class as a command.
 * If this is not set, no meta file will be generated!
 *
 * The @CommandGroup annotation is the described name that will be shown as group/cluster in the workflow editor.
 *
 * The @workflowDocu annotation describes what the element of the command is for. For classes it describes their
 * whole purpose and for fields what are possible inputs and why you can do them.
 *
 */

/**
 * @workflowDocu Greets an entered name
 */
@JavaCommand
@CommandGroup("Example-Commands")
public class HelloWorld {

	/**
	 * The LoggerFactory is a utility class producing Loggers for various logging APIs
	 */
	private static final Logger LOG = LoggerFactory.getLogger(HelloWorld.class);

	/**
	 * The @Persistent annotation means that the value is read or saved from the data store. By default, any
	 * persistent variable is mandatory.
	 * This annotation provides many options, which are described in the JavaDoc.
	 *
	 */

	/**
	 * @workflowDocu Enter the name you want to greet
	 */
	@Persistent
	private String input;

	/**
	 *
	 * @workflowDocu The greeting
	 */
	@Persistent(scope = FieldScope.WRITE_ONLY)
	private String output;

	/**
	 * Methods that are annotated with @Run are executed when the task is called.
	 *
	 */
	@Run
	public void run() {
        this.output = "Hello " + input;
		LOG.info(this.output);
	}
}

Explanations about the individual annotations that can be used for command development can be found in the comments and in the PAK Command Developer Guide

That’s all, our first command is implemented!

In order to use our new developed command we need to create jar out of it and publish it. (In our example we publish it to maven local)

4.1. Publishing the Command Jar-File

Run following cmd command in the root folder of your project

with gradle run gradlew publishToMavenLocal

5. Build a Bpmn Workflow

In order to use our new command in our workflow we need to setup the Commands Repositories for the PAK Editor app.

5.1. Setting Up the Commands

To do so open the menu Preferences → Repositories

Figure 3. Preferences Commands (PAK-Editor)

Select the Folder Button

Select the .m2 folder of your users home and press the Add Button

Save the changes with the Save Changes Button

You can select any folder or directly the created jar-File. We are choosing this option just because we did so above.

After adding the jar file you should be able to refresh the commands at the bottom left and see the following:

Figure 4. HelloWorld-Command

5.2. Build the Workflow

Add the command and an End Node to the workflow

After saving the workflow as „Hello_World.bpmn“ we are basically ready to run this workflow. For this see the Next Steps.

How to Build and Run your first Command

1. What You Will Learn

2. Prerequisites

3. What is a Command?