1. 前置条件

     解压activiti6.0 安装包，进入 activiti-6.0.0/database/create/ 目录

     mysql数据库中创建数据库，这里命名为 activiti

    导入3个 sql 文件，activiti.mysql.create.*.sql (3个文件，* 代表不同的文字，这里不再详细说明)

2. pom.xml 配置

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.5.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.tianjishuju</groupId>
    <artifactId>project_xuji_backend_java</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>project_xuji_backend_java</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <!-- springboot 基本依赖 -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.0.1</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        
        <!-- activiti springboot 依赖 -->
        <dependency>
            <groupId>org.activiti</groupId>
            <artifactId>activiti-spring-boot-starter-basic</artifactId>
            <version>6.0.0</version>
        </dependency>

        <!-- spring rest 服务依赖，这里必须用这个依赖，spring-boot-starter-rest 会导致其它问题产生 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <version>2.1.5.RELEASE</version>
        </dependency>

        <!-- mysql 驱动 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>

        <!-- activiti jpa 依赖，不使用也建议加上，否则在使用@Autowired 注册Bean 时编辑器会显示报错，其实不影响服务正常使用，加上后不再报错 -->
        <dependency>
            <groupId>org.activiti</groupId>
            <artifactId>activiti-spring-boot-starter-jpa</artifactId>
            <version>6.0.0</version>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

3. yml配置

spring:
  datasource:
    url: jdbc:mysql://127.0.0.1:3306/activiti?useUnicode=true&characterEncoding=utf-8
    username: root
    password: 123456

4. idea打开项目加载依赖

5. 添加资源

resource目录下创建processes 目录
并在此目录下创建 one-task-process.bpmn20.xml 文件
文件内容如下：

<?xml version="1.0" encoding="UTF-8"?>
<definitions
      xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL"
      xmlns:activiti="http://activiti.org/bpmn"
      targetNamespace="Examples">

  <process id="oneTaskProcess" name="The One Task Process">
      <startEvent id="theStart" />
      <sequenceFlow id="flow1" sourceRef="theStart" targetRef="theTask" />
      <userTask id="theTask" name="my task" />
      <sequenceFlow id="flow2" sourceRef="theTask" targetRef="theEnd" />
      <endEvent id="theEnd" />
  </process>

</definitions>

6. 在 java 源码App主程序同级目录下创建 controller 和 service目录

创建controller/MyRestController.java 、service/MyService.java 类
MyRestController.java 内容如下：

/**
* @activiti 流程测试类, com.* 代表自己的包名
*/
package com.*.controller;

import com.*.service.MyService;
import org.activiti.engine.task.Task;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import java.util.ArrayList;
import java.util.List;

@RestController
public class MyRestController {

   @Autowired
   private MyService myService;

   @RequestMapping(value="/process", method= RequestMethod.POST)
   public void startProcessInstance() {
       myService.startProcess();
   }

   @RequestMapping(value="/tasks", method= RequestMethod.GET, produces= MediaType.APPLICATION_JSON_VALUE)
   public List<TaskRepresentation> getTasks(@RequestParam String assignee) {
       List<Task> tasks = myService.getTasks(assignee);
       List<TaskRepresentation> dtos = new ArrayList<TaskRepresentation>();
       for (Task task : tasks) {
           dtos.add(new TaskRepresentation(task.getId(), task.getName()));
       }
       return dtos;
   }

   static class TaskRepresentation {

       private String id;
       private String name;

       public TaskRepresentation(String id, String name) {
           this.id = id;
           this.name = name;
       }

       public String getId() {
           return id;
       }
       public void setId(String id) {
           this.id = id;
       }
       public String getName() {
           return name;
       }
       public void setName(String name) {
           this.name = name;
       }

   }

}

service/MyService.java 内容如下：

package com.*.service;

import org.activiti.engine.RuntimeService;
import org.activiti.engine.TaskService;
import org.activiti.engine.task.Task;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.List;

@Service
public class MyService {

    @Autowired
    private RuntimeService runtimeService;

    @Autowired
    private TaskService taskService;

    @Transactional
    public void startProcess() {
        runtimeService.startProcessInstanceByKey("oneTaskProcess");
    }

    @Transactional
    public List<Task> getTasks(String assignee) {
        return taskService.createTaskQuery().taskAssignee(assignee).list();
    }

}

7. 运行项目

8. 访问

分别访问 http://localhost:8080/process,
http://localhost:8080/tasks?assignee=aaa