Building a Leave‑Approval Workflow with Flowable UI and Spring Boot

Overview

Use Flowable's built‑in Flowable‑UI to create a BPMN diagram and develop Spring Boot interfaces to implement the workflow business logic.

1. Deploy Flowable‑UI

Download

https://github.com/flowable/flowable-engine/releases/download/flowable-6.6.0/flowable-6.6.0.zip

, extract flowable-6.6.0\wars\flowable-ui.war, deploy it to Tomcat, and access http://localhost:8080/flowable-ui with the default admin/test credentials.

Configure the database connection in

apache‑tomcat-9.0.37\webapps\flowable-ui\WEB-INF\classes\flowable-default.properties

and copy the MySQL driver mysql-connector-java-5.1.45.jar to apache‑tomcat-9.0.37\webapps\flowable-rest\WEB-INF\lib.

2. Design the Process Diagram

In Flowable‑UI → APP.MODELER draw the leave‑approval flow using events, sequence flows, gateways, and user tasks. Export the BPMN XML for later use.

3. Backend Project Setup

Create a Spring Boot (JDK 8) project with the following Maven dependencies:

<dependency>
  <groupId>org.flowable</groupId>
  <artifactId>flowable-spring-boot-starter</artifactId>
  <version>6.6.0</version>
</dependency>
<dependency>
  <groupId>mysql</groupId>
  <artifactId>mysql-connector-java</artifactId>
  <version>5.1.45</version>
</dependency>

Configure the datasource in application.yml:

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/flowable?useSSL=false&characterEncoding=UTF-8&serverTimezone=GMT%2B8
    driver-class-name: com.mysql.jdbc.Driver
    username: root
    password: 123456

4. Flowable Database Tables

Tables are prefixed with ACT_ and divided into repository (RE), runtime (RU), history (HI), and generic (GE) groups. The article lists the most important tables for each group, such as ACT_RE_PROCDEF, ACT_RU_TASK, and ACT_HI_PROCINST.

5. Engine API & Services

Key services include RepositoryService (deployments and definitions), RuntimeService (start instances), IdentityService (manage users/groups), TaskService (claim/complete tasks), and HistoryService (query completed data).

Code Example

import lombok.extern.slf4j.Slf4j;
import org.flowable.engine.HistoryService;
import org.flowable.engine.RepositoryService;
import org.flowable.engine.RuntimeService;
import org.flowable.engine.history.HistoricProcessInstance;
import org.flowable.engine.repository.Deployment;
import org.flowable.engine.repository.ProcessDefinition;
import org.flowable.engine.runtime.Execution;
import org.flowable.engine.runtime.ProcessInstance;
import org.flowable.idm.api.Group;
import org.flowable.idm.api.User;
import org.flowable.task.api.Task;
import org.flowable.task.api.history.HistoricTaskInstance;
import org.springframework.beans.factory.annotation.Autowired;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.zip.ZipInputStream;

@Slf4j
public class TestFlowable {
    @Autowired private RepositoryService repositoryService;
    @Autowired private RuntimeService runtimeService;
    @Autowired private HistoryService historyService;
    @Autowired private org.flowable.engine.TaskService taskService;
    @Autowired private org.flowable.engine.IdentityService identityService;

    public void createDeploymentZip() {
        try {
            File zipTemp = new File("f:/leave_approval.bpmn20.zip");
            ZipInputStream zipInputStream = new ZipInputStream(new FileInputStream(zipTemp));
            Deployment deployment = repositoryService.createDeployment()
                .addZipInputStream(zipInputStream)
                .deploy();
            log.info("部署成功:{}", deployment.getId());
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
        // ... (rest of the steps: query definitions, start process, claim/complete tasks, query history)
    }
}

6. References

Flowable documentation (Chinese translation)

Official Flowable‑6.6.0 demo

Various blog posts on Flowable usage