Activiti — Lightweight BPMN Workflow Engine for Java

Introduction

Activiti is a BPMN 2.0 process engine written in Java. It allows developers to define, deploy, and execute business processes as visual BPMN diagrams or XML definitions. Activiti is designed to be lightweight and embeddable, running inside any Java application or as a standalone service with a REST API.

What Activiti Does

• Parses and executes BPMN 2.0 process definitions (user tasks, service tasks, gateways, events)
• Manages process instance lifecycle: start, suspend, resume, and terminate
• Assigns human tasks to users and groups with built-in identity management
• Triggers service tasks that call Java delegates, REST endpoints, or scripts
• Persists process state and history to a relational database for audit trails

Architecture Overview

The Activiti engine is a Java library centered on a ProcessEngine that coordinates repository, runtime, task, and history services. BPMN XML is parsed into an in-memory process definition model. At runtime, execution entities traverse the process graph, persisting state changes to a relational database via MyBatis. Activiti 7 added Spring Boot starters and a cloud-native runtime with Spring Cloud integration.

Self-Hosting & Configuration

• Add Activiti Spring Boot starter to your project for auto-configuration
• Place BPMN XML files in src/main/resources/processes/ for auto-deployment
• Configure the database via spring.datasource properties (H2, PostgreSQL, MySQL)
• Expose the REST API by including activiti-spring-boot-starter-rest
• Set spring.activiti.database-schema-update to true for automatic schema migration

Key Features

• Full BPMN 2.0 support including subprocesses, call activities, and event handling
• Built-in REST API for process deployment, execution, and task management
• Spring Boot integration with auto-configuration and actuator endpoints
• Process history and audit logging for compliance and debugging
• Extensible via Java delegates, execution listeners, and task listeners

Comparison with Similar Tools

• Flowable — fork of Activiti 6 with CMMN and DMN support added
• Camunda — another Activiti fork focused on enterprise features and tooling
• jBPM — Red Hat's BPM suite; heavier runtime with rules engine integration
• Temporal — code-first durable execution; Activiti is diagram-first BPMN
• Zeebe — Camunda's cloud-native engine; Activiti 7 also targets cloud deployments

FAQ

Q: What happened between Activiti 6 and 7? A: Activiti 7 was rewritten for cloud-native Spring Boot deployment, adding a new runtime bundle architecture and dropping the legacy Explorer web app.

Q: Can Activiti run without Spring Boot? A: Yes. The core engine is a standalone Java library configurable via activiti.cfg.xml or programmatic API.

Q: How does Activiti persist process state? A: Process state is stored in relational database tables (ACT_RU_*, ACT_HI_*) via MyBatis, supporting H2, PostgreSQL, MySQL, Oracle, and SQL Server.

Q: Is Activiti still actively maintained? A: Activiti 7 receives updates from the community. For projects needing long-term commercial support, consider Flowable or Camunda.

Sources

• https://github.com/Activiti/Activiti
• https://www.activiti.org/documentation