擴充套件Activiti流程定義檔案,實現自定義節點屬性
阿新 • • 發佈:2019-01-08
為了滿足業務需要,流程設計階段需對設計產物流程定義檔案中節點屬性進行擴充套件,譬如:任務是否支援退回、退回方式、退回的節點,任務轉派人、任務可跳轉的節點範圍等屬性資訊。為了保證擴充套件後的流程定義檔案能夠正常解析,我們採用類似<activiti:formProperty>元素的方式,模式如下:
<process id="extensionOperationProcess" name="The process which has extension operations" isExecutable="true"> <startEvent id="start" name="Start"></startEvent> <sequenceFlow id="flow1" sourceRef="start" targetRef="operationTask"></sequenceFlow> <userTask id="operationTask" name="User task which has extension operations" activiti:assignee="admin"> <extensionElements> <activiti:operations> <!-- 轉派: 將當前任務轉派給他人. 可配置屬性如下: transferTo 轉派任務接收人. 可為具體的人,也可為表示式; --> <activiti:transfer transferTo="admin" /> <!-- 退回: 從當前節點退回到前序已執行的節點. 可配置屬性如下: backTo 可退回到的節點範圍,可以逗號間隔可選的節點. 為any時,表示可選任意前序的已執行節點. 預設值為與該節點緊鄰的上一個節點; returnBy 返回方式,可選"track"(原路返回),"flow"(重新流轉). 預設值為track; --> <activiti:turnback backTo="startevent1" returnBy="track" /> <!-- 撤銷: 退回的反向操作?. 可配置屬性如下: gotoBy 前進方式,可選"track"(原路返回),"flow"(重新流轉). 預設值為track; --> </activiti:operations> </extensionElements> </userTask> <sequenceFlow id="flow2" sourceRef="operationTask" targetRef="usertask"></sequenceFlow> <userTask id="usertask" name="User Task" activiti:assignee="user"></userTask> <sequenceFlow id="flow3" sourceRef="usertask" targetRef="end"></sequenceFlow> <endEvent id="end" name="End"></endEvent> </process>
流程定義檔案擴充套件之後,擴充套件的屬性如何儲存呢?我們知道在Activiti中ActivitiImpl物件儲存的是活動節點的定義,那麼我們即可在流程檔案解析時將擴充套件屬性通過setProperty方式儲存到 ActivitiImpl物件中。實現過程如下:
- 自定義使用者任務解析控制類,該類實現將流程定義檔案中的擴充套件屬性設定給ActivitiImpl
- 流程引擎配置中將自定義的使用者任務解析控制類,覆蓋掉預設的使用者任務解析控制類
public class ExtensionUserTaskParseHandler extends UserTaskParseHandler { @Override protected void executeParse(BpmnParse bpmnParse, UserTask userTask) { //呼叫上層的解析 super.executeParse(bpmnParse, userTask); ActivityImpl activity = bpmnParse.getCurrentScope().findActivity(userTask.getId()); Map<String, ExtensionOperation> operationMap = parseUserTaskOperations(bpmnParse, userTask); //將擴充套件屬性設定給activity activity.setProperty(ExtensionBpmnConstants.PROPERTY_OPERATIONS_DEFINITION, operationMap); } public Map<String, ExtensionOperation> parseUserTaskOperations(BpmnParse bpmnParse, UserTask userTask) { Map<String, ExtensionOperation> operationMap = new HashMap<String, ExtensionOperation>(); //獲取擴充套件屬性標籤元素 ExtensionElement operationsElement = userTask.getExtensionElements() .get(ExtensionBpmnConstants.EXTENSION_ELEMENT_OPERATIONS); if (operationsElement != null) { for (ExtensionElement operationElement : operationsElement.getChildElements().values()) { ExtensionOperation userTaskOperation = new ExtensionOperation(operationElement.getName()); if (operationElement != null && !operationElement.getAttributes().isEmpty()) { for (ExtensionAttribute attributeElement : operationElement.getAttributes().values()) { userTaskOperation.addProperty(attributeElement.getName(), attributeElement.getValue()); } } operationMap.put(operationElement.getName(), userTaskOperation); } } return operationMap; } }
- 引擎配置:
完成上述設定後,即可通過 activity.getProperty(ExtensionBpmnConstants.PROPERTY_OPERATIONS_DEFINITION);獲取擴充套件的屬性值。<bean id="processEngineConfiguration" class="org.activiti.engine.impl.cfg.StandaloneInMemProcessEngineConfiguration"> <property name="processEngineName" value="activitiEngineInMemory" /> <property name="jdbcUrl" value="jdbc:h2:mem:activiti;DB_CLOSE_DELAY=1000" /> <property name="jdbcDriver" value="org.h2.Driver" /> <property name="jdbcUsername" value="sa" /> <property name="jdbcPassword" value="" /> <!-- Database configurations --> <property name="databaseSchemaUpdate" value="true" /> <!-- job executor configurations --> <property name="jobExecutorActivate" value="false" /> <!-- mail server configurations --> <property name="mailServerPort" value="5025" /> <property name="customDefaultBpmnParseHandlers"> <list> <bean class="com.cayenne.bpm.engine.kernel.activiti.extension.bpmn.ExtensionUserTaskParseHandler" /> </list> </property> </bean>