/*** 生成流程图** @param processId 任务ID*/
@RequestMapping("/diagram/{processId}")
public void genProcessDiagram(HttpServletResponse response,@PathVariable("processId") String processId) {InputStream inputStream = flowTaskService.diagram(processId);OutputStream os = null;BufferedImage image = null;try {image = ImageIO.read(inputStream);response.setContentType("image/png");os = response.getOutputStream();if (image != null) {ImageIO.write(image, "png", os);}} catch (Exception e) {e.printStackTrace();} finally {try {if (os != null) {os.flush();os.close();}} catch (IOException e) {e.printStackTrace();}}
}

/*** 获取流程过程图*/
public InputStream diagram(String processId) {String processDefinitionId;// 获取当前的流程实例ProcessInstance processInstance = runtimeService.createProcessInstanceQuery().processInstanceId(processId).singleResult();// 如果流程已经结束，则得到结束节点if (Objects.isNull(processInstance)) {HistoricProcessInstance pi = historyService.createHistoricProcessInstanceQuery().processInstanceId(processId).singleResult();processDefinitionId = pi.getProcessDefinitionId();} else {// 如果流程没有结束，则取当前活动节点// 根据流程实例ID获得当前处于活动状态的ActivityId合集ProcessInstance pi = runtimeService.createProcessInstanceQuery().processInstanceId(processId).singleResult();processDefinitionId = pi.getProcessDefinitionId();}// 获得活动的节点List<HistoricActivityInstance> highLightedFlowList = historyService.createHistoricActivityInstanceQuery().processInstanceId(processId).orderByHistoricActivityInstanceStartTime().asc().list();List<String> highLightedFlows = new ArrayList<>();List<String> highLightedNodes = new ArrayList<>();//高亮线for (HistoricActivityInstance tempActivity : highLightedFlowList) {if ("sequenceFlow".equals(tempActivity.getActivityType())) {//高亮线highLightedFlows.add(tempActivity.getActivityId());} else {//高亮节点highLightedNodes.add(tempActivity.getActivityId());}}//获取流程图BpmnModel bpmnModel = repositoryService.getBpmnModel(processDefinitionId);ProcessEngineConfiguration configuration = processEngine.getProcessEngineConfiguration();//获取自定义图片生成器ProcessDiagramGenerator diagramGenerator = new CustomProcessDiagramGenerator();return diagramGenerator.generateDiagram(bpmnModel, "png", highLightedNodes, highLightedFlows, configuration.getActivityFontName(),configuration.getLabelFontName(), configuration.getAnnotationFontName(), configuration.getClassLoader(), 1.0, true);
}