2023年8月1日发(作者：)

activiti5显⽰流程图从数据库中以输⼊流的⽅式读取出图⽚数据，然后在jsp页⾯中读取输⼊流，以图⽚的格式显⽰出图⽚。

InputStream中实际上就是流程图，然后就是以怎样的相应格式显⽰InputStream中的内容。service层 /** * 读取带跟踪的图⽚

*/

public InputStream readResource(String executionId){

InputStream imageStream = null;

ProcessInstance processInstance =ProcessInstanceQuery().processInstanceId(executionId).singleResult();

BpmnModel bpmnModel = nModel(cessDefinitionId());

List activeActivityIds = iveActivityIds(executionId);

ProcessEngineImpl defaultProcessEngine = (ProcessEngineImpl) aultProcessEngine();

cessEngineConfiguration(cessEngineConfiguration());

cessEngineConfiguration(((ProcessEngineImpl) processEngine).getProcessEngineConfiguration());

imageStream = teDiagram(bpmnModel, "png", activeActivityIds);

return imageStream;

}struts2 action中 //从数据库中得到运⾏流程图，带标红 public String readResource(){ HttpServletResponse response = ponse(); HttpServletRequest request = uest(); ActivitiController activitiController = new ActivitiController(); InputStream imageStream = source(processInstanceId); ribute("inputStream", imageStream);

/*byte[] b = new byte[1024]; int len = -1; try { while ((len = (b, 0, 1024)) != -1) { putStream().write(b, 0, len); } } catch (IOException e) { tackTrace(); }*/

return "showImage"; }jsp页⾯ 需要设置response的相应格式 <%

tentType("image/png;charset=UTF-8"); racterEncoding("UTF-8"); InputStream is = (InputStream)ribute("inputStream"); byte[] b = new byte[1024]; int len = -1; while((len = (b, 0, 1024)) != -1) { putStream().write(b, 0, len); // 防⽌异常：getOutputStream() has already been called for this response (); out = dy(); }

%>或者struts2 action中 //从数据库中得到运⾏流程图，带标红 public String readResource(){ HttpServletResponse response = ponse(); HttpServletRequest request = uest(); ActivitiController activitiController = new ActivitiController(); InputStream imageStream = source(processInstanceId); ribute("inputStream", imageStream);

byte[] b = new byte[1024]; int len = -1; try { while ((len = (b, 0, 1024)) != -1) { putStream().write(b, 0, len); } } catch (IOException e) { tackTrace(); }

return null; }在jsp页⾯中⽤oa/leaveAction!readResource"/> 以图⽚的⽅式⾃动加载