// Deleting background tasks - deleting the related file entries as well

import com.liferay.background.task.kernel.util.comparator.BackgroundTaskCreateDateComparator;
import com.liferay.portal.kernel.backgroundtask.BackgroundTask;
import com.liferay.portal.kernel.backgroundtask.BackgroundTaskManagerUtil;

import com.liferay.portal.kernel.dao.orm.QueryUtil;

import java.util.List;

// Group Id of the Site
long groupId = 0;



// Portlet exports
List<BackgroundTask> portletBackgroundTasks =
	BackgroundTaskManagerUtil.getBackgroundTasks(
		groupId, "com.liferay.exportimport.internal.background.task.PortletExportBackgroundTaskExecutor", Boolean.TRUE, QueryUtil.ALL_POS, QueryUtil.ALL_POS, new BackgroundTaskCreateDateComparator());

// Site exports
List<BackgroundTask> layoutBackgroundTasks =
	BackgroundTaskManagerUtil.getBackgroundTasks(
		groupId, "com.liferay.exportimport.internal.background.task.LayoutExportBackgroundTaskExecutor", Boolean.TRUE, QueryUtil.ALL_POS, QueryUtil.ALL_POS, new BackgroundTaskCreateDateComparator());

List<BackgroundTask> backgroundTasks = new ArrayList<>();

backgroundTasks.addAll(portletBackgroundTasks);
backgroundTasks.addAll(layoutBackgroundTasks);

for (BackgroundTask backgroundTask : backgroundTasks) {
	BackgroundTaskManagerUtil.deleteBackgroundTask(backgroundTask.getBackgroundTaskId());
}