【Activiti】跳转到工作流的任意节点（本例用跳转到上一节点讲解即流程回退）

public String taskRollback(String taskId){
//根据要跳转的任务ID获取其任务
HistoricTaskInstance hisTask = historyService
.createHistoricTaskInstanceQuery().taskId(taskId)
.singleResult();
//进而获取流程实例
ProcessInstance instance = runtimeService
.createProcessInstanceQuery()
.processInstanceId(hisTask.getProcessInstanceId())
.singleResult();
//取得流程定义
ProcessDefinitionEntity definition = (ProcessDefinitionEntity) repositoryService.getProcessDefinition(hisTask.getProcessDefinitionId());
//获取历史任务的Activity
ActivityImpl hisActivity = definition.findActivity(hisTask.getTaskDefinitionKey());
//实现跳转
managementService.executeCommand(new JumpCmd(instance.getId(), hisActivity.getId()));
}

public class JumpCmd implements Command<ExecutionEntity>{

private String processInstanceId;
private String activityId;
public static final String REASION_DELETE = "deleted";

public JumpCmd(String processInstanceId, String activityId) {
this.processInstanceId = processInstanceId;
this.activityId = activityId;
}

@Override
public ExecutionEntity execute(CommandContext commandContext) {
ExecutionEntity executionEntity = commandContext.getExecutionEntityManager().findExecutionById(processInstanceId);

executionEntity.destroyScope(REASION_DELETE);
ProcessDefinitionImpl processDefinition = executionEntity.getProcessDefinition();
ActivityImpl activity = processDefinition.findActivity(activityId);
executionEntity.executeActivity(activity);

return executionEntity;
}

}