闲鹿工作流 activiti6.0 显示已结束的流程图

代码参考 闲鹿群友@  

自定义的ProcessController类里，判断流程是否已执行结束，执行结束 则查询历史流程

@RequestMapping(value = "/read-resource")
    public void readResource(String pProcessInstanceId, HttpServletResponse response)
            throws Exception {
        // 设置页面不缓存
        response.setHeader("Pragma", "No-cache");
        response.setHeader("Cache-Control", "no-cache");
        response.setDateHeader("Expires", 0);

        ProcessDefinitionQuery pdq = repositoryService.createProcessDefinitionQuery();

        //运行中的流程
        ProcessInstance processInstance = runtimeService.createProcessInstanceQuery().processInstanceId(pProcessInstanceId).singleResult();
        ProcessDefinition pd;
        if(processInstance == null){
            //历史流程/已结束的流程    比较复杂的流程图不建议显示执行流程，高亮线条流程等 看起来会比较乱
            HistoricProcessInstance historicProcessInstance = historyService.createHistoricProcessInstanceQuery().processInstanceId(pProcessInstanceId).singleResult();
            //已结束流程查询
            pd = pdq.processDefinitionId(historicProcessInstance.getProcessDefinitionId()).singleResult();
        }else{
            //正在执行的流程查询
            pd = pdq.processDefinitionId(processInstance.getProcessDefinitionId()).singleResult();
        }

        String resourceName = pd.getDiagramResourceName();

        if(resourceName.endsWith(".png") && StringUtils.isEmpty(pProcessInstanceId) == false)
        {
            getActivitiProccessImage(pProcessInstanceId,response);
            //ProcessDiagramGenerator.generateDiagram(pde, "png", getRuntimeService().getActiveActivityIds(processInstanceId));
        }
        else
        {
            // 通过接口读取
            InputStream resourceAsStream = repositoryService.getResourceAsStream(pd.getDeploymentId(), resourceName);

            // 输出资源内容到相应对象
            byte[] b = new byte[1024];
            int len = -1;
            while ((len = resourceAsStream.read(b, 0, 1024)) != -1) {
                response.getOutputStream().write(b, 0, len);
            }
        }
    }