审批意见保存在ACT_HI_COMMENT表中
审批状态保存在ACT_HI_VARINST表中，为任务变量

public List<ApprovalEntity> getHistoryTaskByTaskId(String taskId){
        HistoryService historyService = this.getHistoryService();
        TaskService taskService = this.getTaskService();
        HistoricTaskInstance historicTaskInstance = historyService.createHistoricTaskInstanceQuery().taskId(taskId).singleResult();
        String processInstanceId = historicTaskInstance.getProcessInstanceId();
        List<HistoricTaskInstance> historicTaskInstanceList = historyService.createHistoricTaskInstanceQuery()
                .processInstanceId(processInstanceId).orderByTaskCreateTime().asc().list();

        List<ApprovalEntity> approvalEntityList =