DiagramGenerator.java

///usr/bin/env jbang "$0" "$@" ; exit $?

//REPOS mavencentral
//DEPS org.diagramsascode:diagramsascode-image:0.1.2

import org.diagramsascode.core.Diagram;
import org.diagramsascode.image.SequenceDiagramImage;
import org.diagramsascode.sequence.constraint.SequenceDiagramConstraints;
import org.diagramsascode.sequence.edge.Message;
import org.diagramsascode.sequence.node.Participant;
import java.io.File;
import javax.swing.JFrame;
import javax.swing.ImageIcon;
import javax.swing.JLabel;

class DiagramGenerator{
	public static void main(String[] args) throws Exception
	{
		// Create the participants (that exchange messages)
		var participant1 = new Participant("Client");
		var participant2 = new Participant("Server");

		// Create the request and response messages
		var message1 = new Message(participant1, participant2, "Request Message");
		var message2 = new Message(participant2, participant1, "Response Message");

		var diagram = Diagram.builder()
		  .withNodes(participant1, participant2)
		  .withEdges(message1, message2)
		  .withConstraints(new SequenceDiagramConstraints())
		  .build();

		var outputFile = File.createTempFile("sequence", ".png");
		SequenceDiagramImage.of(diagram).writeToPngFile(outputFile);

		System.out.println(outputFile);

		// Show the image using Java Swing. 
		// This could be extracted to a library.
		JFrame frame = new JFrame();
		ImageIcon icon = new ImageIcon(outputFile.getAbsolutePath());
		JLabel label = new JLabel(icon);
		frame.add(label);
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.pack();
		frame.setVisible(true);
	}
}