1. 流程引擎的初始化

ProcessEngine processEngine = ProcessEngines.getDefaultProcessEngine();

2. 部署流程定義

RepositoryService repositoryService = processEngine.getRepositoryService();
Deployment deployment = repositoryService.createDeployment()
  .addClasspathResource("processes/my-process.bpmn20.xml")
  .deploy();

3. 啟動流程實例

RuntimeService runtimeService = processEngine.getRuntimeService();
ProcessInstance processInstance = runtimeService.startProcessInstanceByKey("my-process");

4. 查詢任務

TaskService taskService = processEngine.getTaskService();
List<Task> tasks = taskService.createTaskQuery().taskAssignee("kermit").list();

5. 完成任務

taskService.complete(task.getId());

6. 查詢流程實例

ProcessInstance processInstance = runtimeService.createProcessInstanceQuery().processInstanceId("my-process-id").singleResult();

7. 查詢歷史流程實例

HistoryService historyService = processEngine.getHistoryService();
List<HistoricProcessInstance> historicProcessInstances = historyService.createHistoricProcessInstanceQuery().finished().list();

8. 獲取流程定義信息

RepositoryService repositoryService = processEngine.getRepositoryService();
ProcessDefinition processDefinition = repositoryService.createProcessDefinitionQuery().processDefinitionId(processInstance.getProcessDefinitionId()).singleResult();

這些是使用Activiti框架API的基本技巧，可以幫助您在實際開發中更好地使用Activiti框架。