Comprehensive Guide to Activiti 7 Workflow Engine: Concepts, Environment Setup, Deployment, and Usage

This tutorial introduces workflow fundamentals and explains how Activiti, an open‑source BPM engine, manages business processes using BPMN 2.0 definitions.

1. Workflow Introduction

Defines workflow, its system components, applicable industries, and typical use cases such as order processing, administrative approvals, HR management, finance, and customer service.

2. Activiti 7 Overview

Describes Activiti’s history, its use of BPMN 2.0 for process modeling, and provides the official website and latest version (7.0.0.Beta).

Key BPMN concepts (Event, Activity, Gateway, Flow) are illustrated with XML examples.

3. Environment Setup

Lists required tools (JDK 1.8+, MySQL, Tomcat 8.5, IDEA) and shows how to install the Activiti Designer plugin in IDEA.

Provides Maven dependency snippets for Activiti core, Spring integration, BPMN model, converters, and database drivers.

<dependencyManagement>
  <dependencies>
    <dependency>
      <groupId>org.activiti</groupId>
      <artifactId>activiti-dependencies</artifactId>
      <version>7.0.0.Beta1</version>
      <scope>import</scope>
      <type>pom</type>
    </dependency>
    ...
  </dependencies>
</dependencyManagement>

Shows how to configure activiti.cfg.xml with a processEngineConfiguration bean, JDBC settings, and databaseSchemaUpdate set to "true".

4. Process Deployment

Demonstrates single‑file and ZIP‑based deployment using the RepositoryService API.

ProcessEngine engine = ProcessEngines.getDefaultProcessEngine();
RepositoryService repo = engine.getRepositoryService();
Deployment deployment = repo.createDeployment()
    .addClasspathResource("bpmn/evection.bpmn")
    .addClasspathResource("bpmn/evection.png")
    .name("Leave Request Process")
    .deploy();

Explains related database tables (ACT_RE_DEPLOYMENT, ACT_RE_PROCDEF, ACT_GE_BYTEARRAY) and their relationships.

5. Process Instance Management

Shows how to start a process instance by key, query tasks for a specific assignee, complete tasks, and retrieve process definition details.

RuntimeService runtime = engine.getRuntimeService();
ProcessInstance pi = runtime.startProcessInstanceByKey("myEvection");
TaskService taskService = engine.getTaskService();
Task task = taskService.createTaskQuery()
    .processDefinitionKey("myEvection")
    .taskAssignee("zhangsan")
    .singleResult();
taskService.complete(task.getId());

6. History and Resource Retrieval

Uses HistoryService to query historic activity instances and demonstrates downloading the original BPMN and PNG resources from the database via RepositoryService.

HistoricActivityInstanceQuery query = historyService.createHistoricActivityInstanceQuery()
    .processDefinitionId("myEvection:1:4")
    .orderByHistoricActivityInstanceStartTime().asc();
List<HistoricActivityInstance> list = query.list();
// iterate and print details

Provides code for extracting resources using IOUtils.copy to write the streams to local files.

7. Cleanup

Shows how to delete deployments, with optional cascade deletion to remove running instances.

repositoryService.deleteDeployment(deploymentId, true); // cascade delete

The article concludes with references to further advanced topics such as process suspension, activation, and variables.