Activiti6简明教程

<dependency>
    <groupId>org.activiti</groupId>
    <artifactId>activiti-spring-boot-starter-basic</artifactId>
    <version>6.0.0</version>
</dependency>

spring.activiti.database-schema-update=true

#每次应用启动不检查Activiti数据表是否存在及版本号是否匹配，提升应用启动速度
spring.activiti.database-schema-update=false

#保存历史数据级别设置为full最高级别，便于历史数据的追溯
spring.activiti.history-level=full

@Autowired
private RuntimeService runtimeService;

@Autowired
private TaskService taskService;

@Autowired
private IdentityService identityService;

@Autowired
private RepositoryService repositoryService;

@Autowired
private ProcessEngine processEngine;

@Autowired
private HistoryService historyService;

//项目中每创建一个新用户，对应的要创建一个Activiti用户
//两者的userId和userName一致
User admin=identityService.newUser("1");
admin.setLastName("admin");
identityService.saveUser(admin);

//项目中每创建一个角色，对应的要创建一个Activiti用户组
Group adminGroup=identityService.newGroup("1");
adminGroup.setName("admin");
identityService.saveGroup(adminGroup);

//用户与用户组关系绑定
identityService.createMembership("1","1");

//启动流程实例，字符串"vacation"是BPMN模型文件里process元素的id
ProcessInstance processInstance = runtimeService.startProcessInstanceByKey("vacation");
//流程实例启动后，流程会跳转到请假申请节点
Task vacationApply = taskService.createTaskQuery().processInstanceId(processInstance.getId()).singleResult();
//设置请假申请任务的执行人
taskService.setAssignee(vacationApply.getId(), req.getUserId().toString());

//设置流程参数：请假天数和表单ID
//流程引擎会根据请假天数days>3判断流程走向
//formId是用来将流程数据和表单数据关联起来
Map<String, Object> args = new HashMap<>();
args.put("days", req.getDays());
args.put("formId", formId);

//完成请假申请任务
taskService.complete(vacationApply.getId(), args);

//查出当前登录用户所在的用户组
List<Group> groups = identityService.createGroupQuery()
        .groupMember(String.valueOf(userId)).list();
List<String> groupNames = groups.stream()
        .map(group -> group.getName()).collect(Collectors.toList());

//查询用户组的待审批请假流程列表
List<Task> tasks = taskService.createTaskQuery()
        .processDefinitionKey("vacation")
        .taskCandidateGroupIn(groupNames)
        .listPage(pageNum - 1, pageSize);

//根据流程实例ID查询请假申请表单数据
List<String> processInstanceIds = tasks.stream()
        .map(task -> task.getProcessInstanceId())
        .collect(Collectors.toList());
List<VacationApplyBasicPO> vacationApplyList = 
        vacationRepository.getVacationApplyList(processInstanceIds);

//查询当前审批节点
Task vacationAudit = taskService.createTaskQuery()
        .taskId(req.getTaskId()).singleResult();

if (req.getAuditResult() == 1) {//审批通过
    //设置流程参数：审批ID
    Map<String, Object> args = new HashMap<>();
    args.put("auditId", auditId);

    //设置审批任务的执行人
    taskService.claim(vacationAudit.getId(), req.getUserId().toString());
    //完成审批任务
    taskService.complete(vacationAudit.getId(), args);
} else {
    //审批不通过，结束流程
    runtimeService.deleteProcessInstance(vacationAudit.getProcessInstanceId(), auditId);
}

//controller层代码
@RequestMapping(value = "/image", method = RequestMethod.GET)
public void image(HttpServletResponse response,
 @RequestParam String processInstanceId) {
    try {
        InputStream is = vacationService.getDiagram(processInstanceId);
        if (is == null)
            return;

        response.setContentType("image/png");

        BufferedImage image = ImageIO.read(is);
        OutputStream out = response.getOutputStream();
        ImageIO.write(image, "png", out);

        is.close();
        out.close();
    } catch (Exception ex) {
        logger.error("查看流程图失败", ex);
    }
}

//service层代码
@Override
public InputStream getDiagram(String processInstanceId) {
    //获得流程实例
    ProcessInstance processInstance = runtimeService.createProcessInstanceQuery()
            .processInstanceId(processInstanceId).singleResult();
    String processDefinitionId = StringUtils.EMPTY;
    if (processInstance == null) {
        //查询已经结束的流程实例
        HistoricProcessInstance processInstanceHistory =
                historyService.createHistoricProcessInstanceQuery()
                        .processInstanceId(processInstanceId).singleResult();
        if (processInstanceHistory == null)
            return null;
        else
            processDefinitionId = processInstanceHistory.getProcessDefinitionId();
    } else {
        processDefinitionId = processInstance.getProcessDefinitionId();
    }

    //使用宋体
    String fontName = "宋体";
    //获取BPMN模型对象
    BpmnModel model = repositoryService.getBpmnModel(processDefinitionId);
    //获取流程实例当前的节点，需要高亮显示
    List<String> currentActs = Collections.EMPTY_LIST;
    if (processInstance != null)
        currentActs = runtimeService.getActiveActivityIds(processInstance.getId());

    return processEngine.getProcessEngineConfiguration()
            .getProcessDiagramGenerator()
            .generateDiagram(model, "png", currentActs, new ArrayList<String>(),
                    fontName, fontName, fontName, null, 1.0);
}