springboot特殊问题处理2——springboot集成flowable实现工作流程的完整教程（一）

在实际项目开发过程中，流程相关的业务实现采用工作流会异常清晰明了，但是Activity学习成本和开发难度对追求效率的开发工作者来说异常繁琐，但是作为Activity的亲儿子之一的flowable，其轻量化的使用和对应的api会让开发者感受简单，学习成本很低，值得推荐。

本文案基于springboot2.3.12为例讲解，jdk版本要求至少1.8+，mysql为8.0以上。

一.flowable相关官方网址

官方网站（英文）：https://www.flowable.com/

第三方中文用户手册（V6.3.0）：https://tkjohn.github.io/flowable-userguide/

二.如何集成springboot

1.引入官方jar或者对应springboot的starter

<dependency>
    <groupId>org.flowable</groupId>
    <artifactId>flowable-spring-boot-starter</artifactId>
    <version>${flowable.version}</version>
</dependency>

我这边根据项目需要只引入相关的flowable-engine

        <dependency>
			<groupId>org.flowable</groupId>
			<artifactId>flowable-engine</artifactId>
			<version>6.3.0</version>
			<exclusions>
				<exclusion>
					<groupId>org.mybatis</groupId>
					<artifactId>mybatis</artifactId>
				</exclusion>
				<exclusion>
					<groupId>mysql</groupId>
					<artifactId>mysql-connector-java</artifactId>
				</exclusion>
			</exclusions>
		</dependency>

2. 配置项目需要的数据

• flowable.properties

flowable.url=jdbc:mysql://10.1.0.223:3306/test?autoReconnect=true&useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=CONVERT_TO_NULL&useSSL=false&serverTimezone=CTT&nullCatalogMeansCurrent=true
flowable.username=root
flowable.password=123456
flowable.driverClassName=com.mysql.cj.jdbc.Driver
###生成数据表
flowable.initialize=true
flowable.name=flowable
###动态生成流程执行图（定义中文字体为宋体，防止生成的图片资源存在乱码）
flowable.activityFontName=\u5B8B\u4F53
flowable.labelFontName=\u5B8B\u4F53
flowable.annotationFontName=\u5B8B\u4F53
flowable.xml.encoding=UTF-8

• 项目结构如下 

• 测试需要的流程图 

三.flowable项目正确开发使用流程

1.首先正确配置flowable.properties该文件，默认在启动项目时会生成34张工作流数据表（均已ACT_开头）

2.利用tomcat启动flowable-admin.war，然后用flowable-ui创建对应的bpm文件(或者其他的bpm工具)

3.调用/deployment这个接口，部署已经写好的流程实例，参数参照后台方法说明传递即可

4.分别查看act_re_deployment,act_re_procdef和act_ge_bytearray数据表，如果生成了相关数据即代表部署成功

5.最后就可以在相关模块创建任务开始动态执行流程

四.flowable流程业务实现以及部分关键代码展示

以下关键代码，需要特意说明的是：

• ProcessEngine是flowable提供对公开BPM和工作流操作的所有服务的访问关键对象。

• FlowProcessDiagramGenerator是flowable生成流程实例图片的关键，继承自

  org.flowable.image.impl.DefaultProcessDiagramGenerator类

1.流程部署

    /**
     * 1.部署流程
     *
     * @return
     */
    @GetMapping("/deployment")
    public String deploymentFlowable() {
        RepositoryService repositoryService = processEngine.getRepositoryService();
        Deployment deployment = repositoryService.createDeployment()
                .addClasspathResource("flowable_xml/test_flowable.bpmn20.xml")
                //类别
                .category("审批类")
                .name("领导审批")
                .deploy();
        return ResponseResult.ok(deployment);
    }

2. 查询流程定义

    /**
     * 2.查询流程定义
     *
     * @return
     */
    @GetMapping("/queryDeployment")
    public String queryFlowableDeploy() {
        RepositoryService repositoryService = processEngine.getRepositoryService();
        //查询所有定义的流程
        List<ProcessDefinition> list = repositoryService.createProcessDefinitionQuery().list();
        //查询单个定义的流程
        /*ProcessDefinition processDefinition = repositoryService.createProcessDefinitionQuery()
                .deploymentId("5")
                .singleResult();*/
//        System.out.println("Found process definition : " + processDefinition.getName());
        return ResponseResult.ok(list);
    }

3.启动流程实例

    /**
     * 3.启动流程实例
     *
     * @return
     */
    @RequestMapping("/start/instance")
    public String startProcessInstance() {
        RuntimeService runtimeService = processEngine.getRuntimeService();
        //要启动流程实例，需要提供一些初始化流程变量,自定义
        Map<String, Object> variables = new HashMap<String, Object>(0);
        variables.put("employee", "工作组");
        variables.put("nrOfHolidays", 8);
        variables.put("description", "请假");
        ProcessInstance processInstance =
                runtimeService.startProcessInstanceByKey("leader_approval_key", variables);
        return ResponseResult.ok(processInstance.getName());
    }

4.通过流程执行人员查询任务和流程变量

    /**
     * 通过流程人员定义查询任务和流程变量
     *
     * @return
     */
    @RequestMapping("/query/task")
    public String queryProcessInstance() {
        TaskService taskService = processEngine.getTaskService();
        //通过组查询任务表
//        List<Task> tasks = taskService.createTaskQuery().taskCandidateGroup("managers").list();
        //通过人查询单个任务
        Task task = taskService.createTaskQuery().taskAssignee("小王").singleResult();
        //通过任务id查询流程变量
        Map<String, Object> processVariables = taskService.getVariables(task.getId());
        return ResponseResult.ok(processVariables);
    }

5.通过任务id完成任务

    /**
     * 通过任务id完成任务
     *
     * @return
     */
    @RequestMapping("/complete/task")
    public String completeTask(String taskId) {
        TaskService taskService = processEngine.getTaskService();
        //领导审批提交的表达信息
        Map<String, Object> variables = new HashMap<String, Object>(0);
        taskService.complete(taskId, variables);
        return ResponseResult.ok();
    }

 6.通过流程执行人或者审批人查询审批历史记录

    /**
     * 通过审批人获取历史任务数据
     *
     * @param name
     * @return
     */
    @RequestMapping("/history/task")
    public String getHistoryTask(@RequestParam("name") String name) {
        HistoryService historyService = processEngine.getHistoryService();
        //历史任务流程——流程id
        List<HistoricActivityInstance> activities =
                historyService.createHistoricActivityInstanceQuery()
                        .processInstanceId("2501")
                        .finished()
                        .orderByHistoricActivityInstanceEndTime().asc()
                        .list();
        //历史任务
        List<HistoricTaskInstance> list = historyService.createHistoricTaskInstanceQuery().taskAssignee(name).list();
        return ResponseResult.ok(list.toString());
    }

 7.通过流程id查询流程执行图（多种获取方式）

/**
     * 通过流程id获取流程资源
     *
     * @return
     */
    @RequestMapping("/process/resource")
    public void getProcessResource(HttpServletResponse response) throws IOException {
        RepositoryService repositoryService = processEngine.getRepositoryService();
        /*ProcessDefinition processDefinition = repositoryService.createProcessDefinitionQuery()
                .deploymentId("5085")
                .processDefinitionId("defect_report_flowable:1:5088")
//                .processDefinitionKey("leader_approval_key")
//                .deploymentId("5")
                .singleResult();*/
        BpmnModel bpmnModel = repositoryService.getBpmnModel("defect_report_flowable:1:4");
        InputStream imageStream = processDiagramGenerator.generateDiagram(bpmnModel);
        /*String diagramResourceName = processDefinition.getDiagramResourceName();
        InputStream imageStream = repositoryService.getResourceAsStream(
                processDefinition.getDeploymentId(), diagramResourceName);*/
        FileOutputStream fos = new FileOutputStream("D:\\data\\22222.png");
        byte[] b = new byte[1024];
        int leng = -1;
        while ((leng = imageStream.read(b)) != -1) {
            fos.write(b, 0, leng);
        }
        fos.flush();
        imageStream.close();
        fos.close();
        /*
        //文件流直接写出
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        OutputStream os = response.getOutputStream();
        int ch = 0;
        while (-1 != (ch = imageStream.read())) {
            baos.write(ch);
        }
        os.write(baos.toByteArray());
        imageStream.close();
        baos.close();
        os.close();*/
    }

五.其他相关的功能和问题持续更新，有问题私信 

1.生成流程实例图片的关键代码

@Service
public class FlowProcessDiagramGenerator extends DefaultProcessDiagramGenerator {

    private static final String IMAGE_TYPE = "png";

    @Value("${flowable.activityFontName}")
    private String activityFontName;
    @Value("${flowable.labelFontName}")
    private String labelFontName;
    @Value("${flowable.annotationFontName}")
    private String annotationFontName;
    @Value("${flowable.xml.encoding}")
    private String encoding;

    @Autowired
    private ProcessEngine processEngine;

    /**
     * 生成执行动态图片流
     *
     * @param processDefinitionId 流程定义的id——xml文件规固定的key
     * @param businessKey
     * @return
     */
    public InputStream generateActiveDiagram(String processDefinitionId, String businessKey) {
        RuntimeService runtimeService = processEngine.getRuntimeService();
        HistoryService historyService = processEngine.getHistoryService();
        RepositoryService repositoryService = processEngine.getRepositoryService();
        //1.获取当前的流程定义
        ProcessInstance processInstance = runtimeService.createProcessInstanceQuery()
                .processDefinitionId(processDefinitionId)
//                .processInstanceId(processInstanceId)
                .processInstanceBusinessKey(businessKey)
                .singleResult();
        //流程实例执行的实例id
        String processId = null;
        List<String> activeActivityIds = new ArrayList<>();
        List<String> highLightedFlows = new ArrayList<>();
        //3. 获取流程定义id和高亮的节点id
        if (processInstance != null) {
            //3.1. 正在运行的流程实例
            processId = processInstance.getProcessInstanceId();
            //2.获取所有的历史轨迹线对象
            List<HistoricActivityInstance> historicSquenceFlows = historyService.createHistoricActivityInstanceQuery()
//                .processDefinitionId(processInstanceId)
                    .processInstanceId(processId)
                    .activityType(BpmnXMLConstants.ELEMENT_SEQUENCE_FLOW)
                    .list();
            historicSquenceFlows.forEach(historicActivityInstance -> highLightedFlows.add(historicActivityInstance.getActivityId()));
            activeActivityIds = runtimeService.getActiveActivityIds(processId);
        } else {
            //3.2. 已经结束的流程实例
            HistoricProcessInstance historicProcessInstance = historyService.createHistoricProcessInstanceQuery()
                    .processDefinitionId(processDefinitionId)
//                    .processInstanceId(processId)
                    .processInstanceBusinessKey(businessKey)
                    .singleResult();
            if(historicProcessInstance == null){
                throw new MessageCodeException(MessageCode.FLOWABLE_PROCESS_IS_RELEASE_SUCCESS);
            }
            processId = historicProcessInstance.getId();
            //3.3. 获取结束节点列表
            List<HistoricActivityInstance> historicEnds = historyService.createHistoricActivityInstanceQuery()
                    .processInstanceId(processId)
                    .activityType(BpmnXMLConstants.ELEMENT_EVENT_END).list();
            List<String> finalActiveActivityIds = activeActivityIds;
            historicEnds.forEach(historicActivityInstance -> finalActiveActivityIds.add(historicActivityInstance.getActivityId()));
        }
        //4. 获取bpmnModel对象
        BpmnModel bpmnModel = repositoryService.getBpmnModel(processDefinitionId);
        //模型 活动节点 高亮线
        return generateDiagram(bpmnModel, IMAGE_TYPE, activeActivityIds,
                highLightedFlows, activityFontName, labelFontName, annotationFontName,
                null, 1.0);
    }

    /**
     * 生成工作流程图
     *
     * @param bpmnModel 模型
     * @return
     */
    public InputStream generateDiagram(BpmnModel bpmnModel) {
        return generateDiagram(bpmnModel, IMAGE_TYPE, activityFontName,
                labelFontName, annotationFontName,
                null, 1.0);
    }