activiti流程图上获取各节点的信息获取

背景：

由于项目的需要，当用户在查看流程图时，当点击某个流程图片上的节点时，需要提示一些信息，这就需要获取各个节点的信息，此处获取id和name的值。

注意： 这个并不是流程图的高亮,即当点击网点申请环节时，获取该节点的id和name,即B001和网点申请，点击部门申请时，获取B002和部门经理审批

解释说明：

1.下方说的x和y:

2.流程定义的key: 即为下方id的值

3.节点的id和name的值：

难点分析：

由 于activiti在部署时，如果没有流程图片，则activiti会自动生成一张图片，而我们项目中使用的是activiti modeler实现的在线画流程图，部署时没有图片，是由activiti自动生成。而activiti在生成图片时，会对图片做一个裁剪操作，所有最终 各个节点的坐标会比实际的要小。

（即：activiti自动生成的图片，会做一个裁剪操作，各个节点实际的x和y的值比xml文件中的要小）

而我们的难点在于，各个节点实际坐标的获取。如下图所示：

即我们实际上获取的坐标需要在减去一个minX和minY，得到的才是我们的各个节点实际的坐标。

步骤分析：

1.根据流程定义的key,重新 生成 流程图片，而不是获取流程图片。

2.还是根据流程定义的key,获取各个节点的信息。（ 此处需要注意的是各个节点实际的x和y的值的获取的方法 ）

3.在jsp页面上使用绝对定位，给点击的节点加上高亮。

步骤实现： 1.根据流程定义的key,重新 生成 流程图片，而不是获取流程图片。

此处重新生成图片的原因：

因为有些时候我们在部署流程时，将图片也部署进去了，此时使用的就是自己的图片，activiti不会进行图片的裁剪。因为我在下一步获取流程节点的信息时，对x和y的进行了特殊处理，因此此处需要重新生成 流程图片。

/**

* 根据流程的key生成图片

*

* @param request

* @param response

* @param wfKey 流程定义的key

*/

@RequestMapping("/genericImageByWfKey")

public void genericImageByWfKey(HttpServletRequest request, HttpServletResponse response, String wfKey) {

    Context.setProcessEngineConfiguration(processEngineConfiguration);

    RepositoryService repositoryService = this.processEngine.getRepositoryService();

    ProcessDefinition pd = repositoryService.createProcessDefinitionQuery().processDefinitionKey(wfKey).latestVersion().singleResult();

    BpmnModel bm = repositoryService.getBpmnModel(pd.getId());

    InputStream is = ProcessDiagramGenerator.generatePngDiagram(bm); // 生成图片，获取图片的输入流

    try {

        int size = is.available();

        byte data[] = new byte[size];

        is.read(data);

        response.setContentType("image/png"); // 设置返回的文件类型

        OutputStream os = response.getOutputStream();

        os.write(data);

        os.flush();

        os.close();

    } catch (IOException e) {

        log.error("读写流程图时出现异常！");

    }

        log.info("end....");

}InputStream is = ProcessDiagramGenerator.generatePngDiagram(bm); // 生成图片，获取图片的输入流

    try {

        int size = is.available();

        byte data[] = new byte[size];

        is.read(data);

        response.setContentType("image/png"); // 设置返回的文件类型

        OutputStream os = response.getOutputStream();

        os.write(data);

        os.flush();

        os.close();

    } catch (IOException e) {

        log.error("读写流程图时出现异常！");

    }

        log.info("end....");

}

2.还是根据流程定义的key,获取各个节点的信息。

获取各个节点的坐标之前，我们先看一下activiti中是如果获取到最小的x和y的，然后是如何裁剪图片的

2.1获取节点包括线的最小x和最小y :

跟踪acticiti的源码可以发现，最小x和y的获取（org.activiti.engine.impl.bpmn.diagram.ProcessDiagramGenerator.initProcessDiagramCanvas(BpmnModel)）

protected static ProcessDiagramCanvas initProcessDiagramCanvas(BpmnModel bpmnModel) {

    // We need to calculate maximum values to know how big the image will be in its entirety

    double minX = Double.MAX_VALUE;

    double maxX = 0;

    double minY = Double.MAX_VALUE;

    double maxY = 0;

    for (Pool pool : bpmnModel.getPools()) {

      GraphicInfo graphicInfo = bpmnModel.getGraphicInfo(pool.getId());

      minX = graphicInfo.getX();

      maxX = graphicInfo.getX() + graphicInfo.getWidth();

      minY = graphicInfo.getY();

      maxY = graphicInfo.getY() + graphicInfo.getHeight();

    }

    List<FlowNode> flowNodes = gatherAllFlowNodes(bpmnModel);

    for (FlowNode flowNode : flowNodes) {

      GraphicInfo flowNodeGraphicInfo = bpmnModel.getGraphicInfo(flowNode.getId());

      // width

      if (flowNodeGraphicInfo.getX() + flowNodeGraphicInfo.getWidth() > maxX) {

        maxX = flowNodeGraphicInfo.getX() + flowNodeGraphicInfo.getWidth();

      }

      if (flowNodeGraphicInfo.getX() < minX) {

        minX = flowNodeGraphicInfo.getX();

      }

      // height

      if (flowNodeGraphicInfo.getY() + flowNodeGraphicInfo.getHeight() > maxY) {

        maxY = flowNodeGraphicInfo.getY() + flowNodeGraphicInfo.getHeight();

      }

      if (flowNodeGraphicInfo.getY() < minY) {

        minY = flowNodeGraphicInfo.getY();

      }

      for (SequenceFlow sequenceFlow : flowNode.getOutgoingFlows()) {

        List<GraphicInfo> graphicInfoList = bpmnModel.getFlowLocationGraphicInfo(sequenceFlow.getId());

        for (GraphicInfo graphicInfo : graphicInfoList) {

          // width

          if (graphicInfo.getX() > maxX) {

            maxX = graphicInfo.getX();

          }

          if (graphicInfo.getX() < minX) {

            minX = graphicInfo.getX();

          }

          // height

          if (graphicInfo.getY() > maxY) {

            maxY = graphicInfo.getY();

          }

          if (graphicInfo.getY()< minY) {

            minY = graphicInfo.getY();

          }

        }

      }

    }

    int nrOfLanes = 0;

    for (Process process : bpmnModel.getProcesses()) {

      for (Lane l : process.getLanes()) {

        nrOfLanes++;

        GraphicInfo graphicInfo = bpmnModel.getGraphicInfo(l.getId());

        // // width

        if (graphicInfo.getX() + graphicInfo.getWidth() > maxX) {

          maxX = graphicInfo.getX() + graphicInfo.getWidth();

        }

        if (graphicInfo.getX() < minX) {

          minX = graphicInfo.getX();

        }

        // height

        if (graphicInfo.getY() + graphicInfo.getHeight() > maxY) {

          maxY = graphicInfo.getY() + graphicInfo.getHeight();

        }

        if (graphicInfo.getY() < minY) {

          minY = graphicInfo.getY();

        }

      }

    }

    // Special case, see http://jira.codehaus.org/browse/ACT-1431

    if (flowNodes.size() == 0 && bpmnModel.getPools().size() == 0 && nrOfLanes == 0) {

      // Nothing to show

      minX = 0;

      minY = 0;

    }

    return new ProcessDiagramCanvas((int) maxX + 10,(int) maxY + 10, (int) minX, (int) minY);

  }new ProcessDiagramCanvas((int) maxX + 10,(int) maxY + 10, (int) minX, (int) minY);

  }

2.2 图片的裁剪：

还是activiti的源码：（org.activiti.engine.impl.bpmn.diagram.ProcessDiagramCanvas.generateImage(String)）

/**

   * Generates an image of what currently is drawn on the canvas.

   *

   * Throws an {@link ActivitiException} when {@link #close()} is already

   * called.

   */

  public InputStream generateImage(String imageType) {

    if (closed) {

      throw new ActivitiException("ProcessDiagramGenerator already closed");

    }

    ByteArrayOutputStream out = new ByteArrayOutputStream();

    try {

      // Try to remove white space

      minX = (minX <= 5) ? 5 : minX;

      minY = (minY <= 5) ? 5 : minY;

      BufferedImage imageToSerialize = processDiagram;

      if (minX >= 0 && minY >= 0) {

        // 此处的最小x和最小y减去了5

        imageToSerialize = processDiagram.getSubimage(minX - 5, minY - 5, canvasWidth - minX + 5, canvasHeight - minY + 5); // 此处可以看到，activiti对图像做了裁剪的操作。

      }

      ImageIO.write(imageToSerialize, imageType, out);

    } catch (IOException e) {

      throw new ActivitiException("Error while generating process image", e);

    } finally {

      IoUtil.closeSilently(out);

    }

    return new ByteArrayInputStream(out.toByteArray());

  }       // 此处的最小x和最小y减去了5

        imageToSerialize = processDiagram.getSubimage(minX - 5, minY - 5, canvasWidth - minX + 5, canvasHeight - minY + 5); // 此处可以看到，activiti对图像做了裁剪的操作。

      }

      ImageIO.write(imageToSerialize, imageType, out);

    } catch (IOException e) {

      throw new ActivitiException("Error while generating process image", e);

    } finally {

      IoUtil.closeSilently(out);

    }

    return new ByteArrayInputStream(out.toByteArray());

  }

2.3 我们自己的各个节点的信息获取

@RequestMapping("/getProcessTrace")

	@ResponseBody

	/**

	 * 获取各个节点的具体的信息

	 * @param wfKey

	 * 		流程定义的key

	 * @return

	 */

	public List<Map<String, Object>> getProcessTrace(String wfKey) throws Exception {

		List<Map<String, Object>> activityInfos = new ArrayList<Map<String, Object>>();

		RepositoryService repositoryService = processEngine.getRepositoryService();

		ProcessDefinition pd = repositoryService.createProcessDefinitionQuery().processDefinitionKey(wfKey).latestVersion().singleResult();

		ProcessDefinitionEntity processDefinition = (ProcessDefinitionEntity) ((RepositoryServiceImpl) repositoryService).getDeployedProcessDefinition(pd.getId());

		List<ActivityImpl> activitiList = processDefinition.getActivities();

		InputStream xmlIs = repositoryService.getResourceAsStream(processDefinition.getDeploymentId(), processDefinition.getResourceName());

		BpmnModel bm = new BpmnXMLConverter().convertToBpmnModel(new InputStreamSource(xmlIs), false, true);

                // 下方使用反射获取最小的x和y，仔细看就会发现调用的是上方2.1节的方法

		Class<?> clazz = Class.forName("org.activiti.engine.impl.bpmn.diagram.ProcessDiagramGenerator");

		Method method = clazz.getDeclaredMethod("initProcessDiagramCanvas", BpmnModel.class);

		method.setAccessible(true);

		ProcessDiagramCanvas pdc = (ProcessDiagramCanvas) method.invoke(clazz.newInstance(), bm); // 调用方法

		clazz = Class.forName("org.activiti.engine.impl.bpmn.diagram.ProcessDiagramCanvas");

		Field minXField = clazz.getDeclaredField("minX"); // 得到minX字段

		Field minYField = clazz.getDeclaredField("minY");

		minXField.setAccessible(true);

		minYField.setAccessible(true);

		int minX = minXField.getInt(pdc);// 最小的x值

		int minY = minYField.getInt(pdc); // 最小的y的值



		minX = minX > 0 ? minX - 5 : 0;   // 此处为什么需要减5，上方2.2中activiti源码中有

		minY = minY > 0 ? minY - 5 : 0;

		for (ActivityImpl activity : activitiList) {

			Map<String, Object> activityInfo = new HashMap<String, Object>();

			activityInfo.put("width", activity.getWidth());

			activityInfo.put("height", activity.getHeight());

			activityInfo.put("x", activity.getX() - minX);

			activityInfo.put("y", activity.getY() - minY);

			activityInfo.put("actId", activity.getId());

			activityInfo.put("name", activity.getProperty("name"));  // ActivityImpl 中没有getName方法，所以此处需要这样获取。

			activityInfos.add(activityInfo);

		}

		return activityInfos;

	} // 下方使用反射获取最小的x和y，仔细看就会发现调用的是上方2.1节的方法

		Class<?> clazz = Class.forName("org.activiti.engine.impl.bpmn.diagram.ProcessDiagramGenerator");

		Method method = clazz.getDeclaredMethod("initProcessDiagramCanvas", BpmnModel.class);

		method.setAccessible(true);

		ProcessDiagramCanvas pdc = (ProcessDiagramCanvas) method.invoke(clazz.newInstance(), bm); // 调用方法

		clazz = Class.forName("org.activiti.engine.impl.bpmn.diagram.ProcessDiagramCanvas");

		Field minXField = clazz.getDeclaredField("minX"); // 得到minX字段

		Field minYField = clazz.getDeclaredField("minY");

		minXField.setAccessible(true);

		minYField.setAccessible(true);

		int minX = minXField.getInt(pdc);// 最小的x值

		int minY = minYField.getInt(pdc); // 最小的y的值



		minX = minX > 0 ? minX - 5 : 0;   // 此处为什么需要减5，上方2.2中activiti源码中有

		minY = minY > 0 ? minY - 5 : 0;

		for (ActivityImpl activity : activitiList) {

			Map<String, Object> activityInfo = new HashMap<String, Object>();

			activityInfo.put("width", activity.getWidth());

			activityInfo.put("height", activity.getHeight());

			activityInfo.put("x", activity.getX() - minX);

			activityInfo.put("y", activity.getY() - minY);

			activityInfo.put("actId", activity.getId());

			activityInfo.put("name", activity.getProperty("name"));  // ActivityImpl 中没有getName方法，所以此处需要这样获取。

			activityInfos.add(activityInfo);

		}

		return activityInfos;

	}

3.在jsp页面上使用绝对定位，给点击的节点加上高亮。

<html>

	<head>

		<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">

		<title>Insert title here</title>

		<style type="text/css">

			.activity-attr{border-radius: 10px; border: 3px solid red; transition:ease-out 0.5s; box-shadow:0px 0px 9px red;}

			#processKey{color: red;}

			#flowImageAndRect{position: relative;overflow: scroll;height:300px; heibackground-image: url('${ctx}/resources/images/workflow/grid_10.png')}

			body,html{margin: 0px;padding:0px;}

		</style>

		<script type="text/javascript">

			$(function(){

				var wfKey = '${param.wfKey}'; // 流程定义的key

				var $flowImageAndRect = $('#flowImageAndRect');

				$('#processKey').html('流程定义的key --> ' + wfKey);

				// 加载流程图片

				loadProcessImage(wfKey,$flowImageAndRect);

				// 加载各节点信息，最终实现，在点击图片上的各节点时，出现高亮

				setTimeout(function(){

					loadProcessTrace(wfKey,$flowImageAndRect);

				},200);

				var $revClickRect = null; // 上次点击的图形

				// 绑定click事件，点击实现，只有点击的不是同一个时，才显示红色的边框（如果多次点击同一个，红色的边框只出现一次）

				$('#flowImageAndRect').off('click').on('click','.activity-attr',function(e){

					var $this = $(this);

					var prevFlag = false; // 是上一个图形，避免多次点击同一个

					if($revClickRect){ // 说明不是第一次点击

						prevFlag = ($revClickRect.attr('actId')!=$this.attr('actId')) ? false : true;// 说明2次点击的不是同一个

						if(!prevFlag)

							$revClickRect.css('opacity','0');

					}

					if(!prevFlag){ // 此处可以请求后台，加载相关的数据（多次点击同一个，下方可确保只执行一次）

						$this.css('opacity','1'); // 显示当前的

						$revClickRect = $this; // 将当前设置为上次点击的

						$('#info').html('节点ID --> ' + $this.attr('actId') + "  |  " + "节点名称 --> " + $this.attr('name'));

					}

				});

			});

			/**

			 * 加载图片

			 */

			function loadProcessImage(wfKey,$flowImageAndRect){

				var imageUrl = '${ctx}/workflow/monitor/genericImageByWfKey.do?wfKey='+wfKey;

				// 加载图片

				$('<img />',{

					"src" : imageUrl,

					"alt" : ''

				}).appendTo($flowImageAndRect);

			}

			/**

			 * 加载流程中各节点的信息

			 * @param wfKey : 流程定义的key

			 * @param $flowImageAndRect

			 */

			function loadProcessTrace(wfKey,$flowImageAndRect){

				var traceUrl = '${ctx}/workflow/monitor/getProcessTrace.do?wfKey='+wfKey;

				$.getJSON(traceUrl,function(infos){

					var html = "";

					$.each(infos,function(i,v){

						// 矩形的div

						var $div = $('<div/>', {

				                'class': 'activity-attr'

			            }).css({

			                position: 'absolute',

			                left: v.x,

			                top: v.y,

			                width: v.width - 3,

			                height:v.height - 3,

			                opacity: 0,

			                zIndex: 100,

					cursor : 'pointer'

			            }).attr({'actId':v.actId,'name':v.name});

						html += $div.prop("outerHTML");

					});

					$('<div />',{'id':'processRect'}).html(html).appendTo($flowImageAndRect);

				});

			}

		</script>

	</head>

	<body>

		<div id="main">

			<div id="flowImageAndRect">

			</div>

			<div id="processKey" style="font-size: 52px;text-align: center;margin-bottom: 50px;">

			</div>

			<div id="info" style="font-size: 52px;text-align: center;">

			</div>

		</div>

	</body>

</html>

到此，已经完成了。