Activiti工作流查看流程视图

思路

首先我们要知道Activiti工作流查看流程针对的是运行的实例， 可以看到流程流转到那个节点。
但是大多数情况实例对业务来说是没有意义的，那么我就需要业务key，每个业务key对应工作流唯一的task任务。
有了这些想法我们就能构思查看流程视图的接口了，入参肯定是业务能够提供的，出参没有疑问那就是图片了，为了方便我们直接返回图片流InputStream

业务key转换流程实例

  通过businessKey 查询业务key对应的task任务
   List tasks = taskService.createTaskQuery().processInstanceBusinessKey(businessKey).list();
  理论上来说业务businessKey也是唯一的，但是对Activiti来说只是某一列返回List，没事我们直接加判断，不唯一就异常出去。
   if(tasks != null && tasks.size() == 1){
      String taskId = tasks.get(0).getId();
      Task nowTask = taskService.createTaskQuery().taskId(taskId).singleResult();
       processInstanceId = nowTask.getProcessInstanceId();
       ProcessInstance processInstance = runtimeService.createProcessInstanceQuery().processInstanceId(processInstanceId).singleResult();
       processDefinitionId = processInstance.getProcessDefinitionId();
    }else if (tasks != null && tasks.size() == 0){
        List list = historyService.createHistoricProcessInstanceQuery().finished().processInstanceBusinessKey(businessKey).list();
        if(list != null && list.size() == 1){
            processDefinitionId = list.get(0).getProcessDefinitionId();
            processInstanceId = list.get(0).getId();
        }
    }

有了思路不多说直接上代码

public InputStream _$look_png(String businessKey) {
     
            logger.info("_$look_png---参数businessKey="+businessKey);
            InputStream inputStream= null;
            String processInstanceId = null;
            String processDefinitionId = null;
            try {
     
                List<Task> tasks = taskService.createTaskQuery().processInstanceBusinessKey(businessKey).list();
                logger.info("_$look_png---任务tasks="+ tasks);
                if(tasks != null && tasks.size() == 1){
     
                    String taskId = tasks.get(0).getId();
                    Task nowTask = taskService.createTaskQuery().taskId(taskId).singleResult();
                    processInstanceId = nowTask.getProcessInstanceId();
                    ProcessInstance processInstance = runtimeService.createProcessInstanceQuery().processInstanceId(processInstanceId).singleResult();
                    processDefinitionId = processInstance.getProcessDefinitionId();
                }else if (tasks != null && tasks.size() == 0){
     
                    List<HistoricProcessInstance> list = historyService.createHistoricProcessInstanceQuery().finished().processInstanceBusinessKey(businessKey).list();
                    if(list != null && list.size() == 1){
     
                        processDefinitionId = list.get(0).getProcessDefinitionId();
                        processInstanceId = list.get(0).getId();
                    }
                }

            if(StringUtils.isBlank(processInstanceId) || StringUtils.isBlank(processDefinitionId)){
     
                logger.info("_$look_png---异常，未找到或发现多个流程！businessKey="+businessKey);
                String result = "未找到或发现多个流程！businessKey="+businessKey;
                inputStream = new ByteArrayInputStream(result.getBytes());
                return inputStream;
            }
            BpmnModel bpmnModel = repositoryService.getBpmnModel(processDefinitionId);
            List<HistoricActivityInstance> activityInstances = historyService.createHistoricActivityInstanceQuery().processInstanceId(processInstanceId).orderByHistoricActivityInstanceStartTime().asc().list();
            List<String> activityIds = new ArrayList<String>();
            List<String> flowIds = new ArrayList<String>();
            ProcessDefinitionEntity processDefinition = (ProcessDefinitionEntity) ((RepositoryServiceImpl) repositoryService).getDeployedProcessDefinition(processDefinitionId);
            //获取流程走过的线
            flowIds = getHighLightedFlows(processDefinition, activityInstances);
            for (HistoricActivityInstance hai : activityInstances) {
     
                //获取流程走过的节点
                activityIds.add(hai.getActivityId());
            }

            ImageIO.setCacheDirectory(new File(_PNG_PATH));
            inputStream = processEngine.getProcessEngineConfiguration().getProcessDiagramGenerator().generateDiagram(bpmnModel, "png", activityIds, flowIds,"宋体", "宋体", "宋体", null, 1.0);

        }catch (Exception e){
     
            e.printStackTrace();
            logger.error("_$look_png---异常：", e);
        }

        return inputStream;
    }

这里有个注意的地方， linux注意安装字体
linux 安装字体
yum install -y fontconfig mkfontscale
将 宋体 丢入/usr/share/fonts/
建立字体索引信息，更新字体缓存，使用如下命令：
mkfontscale
mkfontdir
fc-cache
查看安装字体fc-list，重启服务

//获取流程走过的线
    public static List<String> getHighLightedFlows(ProcessDefinitionEntity processDefinitionEntity,List<HistoricActivityInstance> haiList) throws Exception{
     
        //用来保存高亮的线 flowId
        List<String> highFlows = new ArrayList<String>();
        for (int i = 0; i < haiList.size() - 1; i++) {
     
            //对历史流程节点进行遍历
            //得到节点定义的详细信息
            ActivityImpl activityImpl = processDefinitionEntity.findActivity(haiList.get(i).getActivityId());
            //用以保存后需要开始时间相同的节点
            List<ActivityImpl> sameStartTimeNodes = new ArrayList<ActivityImpl>();
            ActivityImpl sameActivityImpl1 = processDefinitionEntity.findActivity(haiList.get(i + 1).getActivityId());
            //讲后面第一个节点放在时间相同节点的集合里
            sameStartTimeNodes.add(sameActivityImpl1);
            for (int j = i + 1; j < haiList.size() - 1; j++) {
     
                HistoricActivityInstance activityImpl1 = haiList.get(j);//后续第一个节点
                HistoricActivityInstance activityImpl2 = haiList.get(j + 1);//后续第而个节点
                if(activityImpl1.getStartTime().equals(activityImpl2.getStartTime())){
     
                    //如果第一个节点和第二个节点开始时间相同保存
                    ActivityImpl sameActivityImpl2 = processDefinitionEntity.findActivity(activityImpl2.getActivityId());
                    sameStartTimeNodes.add(sameActivityImpl2);
                }else{
     
                    //不同就调查循环
                    break;
                }
            }
            //取出节点的所有出去的线
            List<PvmTransition> pvmTransitions = activityImpl.getOutgoingTransitions();
            for(PvmTransition pvmTransition : pvmTransitions){
     
                //对所有的线进行遍历
                ActivityImpl pvmActivityImpl = (ActivityImpl) pvmTransition.getDestination();
                //如果取出的线的目标节点存在时间相同的节点里，保存该线的id，进行高亮显示
                if(sameStartTimeNodes.contains(pvmActivityImpl)){
     
                    highFlows.add(pvmTransition.getId());
                }
            }
        }
        return highFlows;
    }