interro_robot/src/main/java/com/supervision/service/impl/RobotTalkServiceImpl.java

package com.supervision.service.impl;

import cn.hutool.core.codec.Base64;
import cn.hutool.core.collection.CollUtil;
import cn.hutool.core.convert.Convert;
import cn.hutool.core.date.TimeInterval;
import cn.hutool.core.io.FileUtil;
import cn.hutool.core.io.IoUtil;
import cn.hutool.core.lang.Assert;
import cn.hutool.core.util.NumberUtil;
import cn.hutool.core.util.StrUtil;
import cn.hutool.json.JSONUtil;
import com.supervision.domain.*;
import com.supervision.dto.paddlespeech.res.TtsResultDTO;
import com.supervision.dto.robot.*;
import com.supervision.dto.matchTool.ExtractInformationDTO;
import com.supervision.dto.matchTool.MatchQuestionAnswerDTO;
import com.supervision.dto.QueryProcessDTO;
import com.supervision.mapper.RobotDataMapper;
import com.supervision.service.*;
import com.supervision.util.UserUtil;
import com.supervision.vo.robot.ArchivesReqVo;
import com.supervision.vo.robot.CommonDialogVo;
import com.supervision.vo.talk.RobotTalkReq;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.web.multipart.MultipartFile;

import javax.annotation.Resource;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.IOException;
import java.math.BigDecimal;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.stream.Collectors;

@Slf4j
@Service
@RequiredArgsConstructor
public class RobotTalkServiceImpl implements RobotTalkService {

    private final QueryTemplateProcessor queryTemplateProcessor;

    private final MatchToolService matchToolService;

    private final VoiceService voiceService;

    private final IrRobotConfigService irRobotConfigService;

    private final IrSessionHistoryService sessionService;

    private final IrSessionParamService irSessionParamService;

    private final IrVoiceService irVoiceService;

    private final IrFileService irFileService;

    @Resource
    private final RobotDataMapper robotDataMapper;

    @Override
    @Transactional(rollbackFor = Exception.class)
    public RobotTalkDTO textTalk2Robot(RobotTalkReq robotTalkReq) {
        String sessionId = robotTalkReq.getSessionId();
        Assert.notEmpty(sessionId, "sessionId不能为空");
        TimeInterval timeInterval = new TimeInterval();
        timeInterval.start("all");
        log.info("textTalk2Robot:开始问答,参数:{}",JSONUtil.toJsonStr(robotTalkReq));

        RobotTalkDTO robotTalkDTO = RobotTalkDTO.builder()
                .sessionId(sessionId).doNext(true)
                .askInfo(AskInfo.builder().contentType(1).message(robotTalkReq.getMessage()).build())
                .answerInfo(AnswerInfo.builder().contentType(robotTalkReq.getAnswerType()).build())
                .build();

        // 获取机器人配置
        IrRobotConfig config = irRobotConfigService.lambdaQuery().one();

        // 确认弹框信息
        if (StrUtil.isNotEmpty(robotTalkReq.getAskId())){
            IrSessionHistory sessionHistory = sessionService.lambdaQuery().eq(IrSessionHistory::getId, robotTalkReq.getAskId()).one();
            if (Objects.nonNull(sessionHistory)){
                robotTalkReq.setMessage(sessionHistory.getUserQuestion());
                robotTalkReq.setConfirmFlag(true);
                robotTalkDTO.getAskInfo().setAskId(robotTalkReq.getAskId());
            }
        }

        // 匹配问题意图
        MatchQuestionAnswerDTO matchQuestionAnswerDTO = matchQuestionAnswer(robotTalkReq.getMessage());
        setSuspectInfoAndNextFlag(robotTalkReq, robotTalkDTO, matchQuestionAnswerDTO,config);

        if (Objects.isNull(matchQuestionAnswerDTO) && robotTalkDTO.isDoNext()){
            // 未匹配到查询意图,设置默认错误语
            log.info("问题:{}未匹配到意图",robotTalkReq.getMessage());
            robotTalkDTO.getAnswerInfo().setMessage(config.getErrorLanguage());
            robotTalkDTO.setDoNext(false);
        }

        if (robotTalkDTO.isDoNext()){
            QueryProcessDTO matchAnswer = queryMatch2Answer(sessionId, matchQuestionAnswerDTO, robotTalkDTO, robotTalkReq.getTitleContent());
            if (Integer.valueOf(0).equals(matchAnswer.getState()) &&
                    Integer.valueOf(3).equals(matchAnswer.getContentType())
                    && matchAnswer.getByteContent() != null){
                // 查询结果类型为字节数组
                robotTalkDTO.getAnswerInfo().setContentType(3);
                robotTalkDTO.getAnswerInfo().setAnswerByte(matchAnswer.getByteContent());
            }else{
                robotTalkDTO.getAnswerInfo().setAnswerFile(matchAnswer.getFileContent());
                robotTalkDTO.getAnswerInfo().setMessage(decideAnswer(matchAnswer, config));
                if (matchAnswer.getState() == 1){
                    if (!Boolean.TRUE.equals(robotTalkReq.isConfirmFlag())){
                        robotTalkDTO.getAnswerInfo().setContentType(6);
                    }
                }
            }
        }

        logSessionInfo(robotTalkDTO, matchQuestionAnswerDTO);

        // 清除中间数据
        robotTalkDTO.getAnswerInfo().setVoiceBase64(null);
        robotTalkDTO.getAnswerInfo().setAnswerByte(null);
        robotTalkDTO.getAnswerInfo().setAnswerFile(null);

        log.info("textTalk2Robot:结束问答,耗时:{}ms",timeInterval.interval("all"));
        return robotTalkDTO;
    }

    /**
     * 转换语句中的数字，方便语音合成发音
     * @param input
     * @return
     */
    private String numberToChinese(String input){

        if (StrUtil.isEmpty(input)){
            return input;
        }
        String regex = "(\\d+(\\.\\d+)?)(?=元|万元|亿元|个)";
        Pattern pattern = Pattern.compile(regex);
        Matcher matcher = pattern.matcher(input);

        while (matcher.find()) {
            String group = matcher.group();
            if (StrUtil.isNotEmpty(group) && NumberUtil.isNumber(group)){
                input = input.replace(group,Convert.numberToChinese(NumberUtil.parseDouble(group),false));
            }
        }
        return input;
    }


    private void setSuspectInfoAndNextFlag(RobotTalkReq robotTalkReq, RobotTalkDTO robotTalkDTO, MatchQuestionAnswerDTO matchQuestionAnswerDTO, IrRobotConfig config) {

        String sessionId = robotTalkReq.getSessionId();

        if (Objects.nonNull(matchQuestionAnswerDTO)){
            List<ParamCheckDTO> paramCheckDTOS = queryTemplateProcessor.paramCheck(matchQuestionAnswerDTO.getMatchQuestionCode(), sessionId,
                    suspectInfo2IrSessionParam(sessionId, null));
            // 匹配到意图，但是参数校验不通过，尝试提取消息中的信息
            if (CollUtil.isNotEmpty(paramCheckDTOS) && !Boolean.TRUE.equals(robotTalkReq.isConfirmFlag())){
                String paramsJoin = paramCheckDTOS.stream().map(ParamCheckDTO::getParamName).collect(Collectors.joining(","));
                log.info("匹配到的问题:{} ,需要参数:{} ,尝试抽取问题:{} 中的参数。",matchQuestionAnswerDTO.getMatchQuestionCode(),paramsJoin, robotTalkReq.getMessage());
                extractInformation(sessionId, robotTalkReq.getMessage(), robotTalkDTO);
                SuspectInfo suspectInfo = robotTalkDTO.getAnswerInfo().getSuspectInfo();
                if (Objects.isNull(suspectInfo) || suspectInfo.isEmpty()){
                    // 未抽取到信息,继续下一步操作
                    robotTalkDTO.setDoNext(true);
                }else {
                    robotTalkDTO.getAnswerInfo().setContentType(6);
                }
            }
        }else {
            if (!Boolean.TRUE.equals(robotTalkReq.isConfirmFlag())){
                log.info("问题:{},未匹配到意图，且confirmFlag标识不为true,抽取问题中的关键属性", robotTalkReq.getMessage());
                // 未匹配到意图，且不是关键信息确认操作则提取信息中的关键信息
                extractInformation(sessionId, robotTalkReq.getMessage(), robotTalkDTO);
            }else {
                // 未匹配到意图，是关键信息确认操作，不做问题响应，只做默认回答
                log.info("问题:{},未匹配到意图，且confirmFlag标识为true,设置默认回答:{}", robotTalkReq.getMessage(), config.getUnrecognizedTwo());
                robotTalkDTO.getAnswerInfo().setMessage(config.getUnrecognizedTwo());
                robotTalkDTO.setDoNext(false);
            }
        }
        SuspectInfo suspectInfo = robotTalkDTO.getAnswerInfo().getSuspectInfo();
        if (Objects.isNull(suspectInfo) || suspectInfo.isEmpty()){
            robotTalkDTO.getAnswerInfo().setSuspectInfo(robotTalkReq.getTitleContent());
        }
    }

    private void logSessionInfo(RobotTalkDTO robotTalkDTO, MatchQuestionAnswerDTO matchQuestionAnswerDTO) {
        // 组装日志信息
        IrSessionHistory irSessionHistory = talk2SessionHistory(robotTalkDTO.getSessionId(),
                robotTalkDTO, matchQuestionAnswerDTO);

        // 保存回答音频文件
        IrVoice irVoice = saveAudioIfNoAbsent(robotTalkDTO.getAnswerInfo().getMessage());
        if (Objects.nonNull(irVoice)) {
            robotTalkDTO.getAnswerInfo().setVoiceBaseId(irVoice.getId());
            robotTalkDTO.getAnswerInfo().setVoiceBase64(irVoice.getVoiceBase64());
            robotTalkDTO.getAnswerInfo().setAudioLength(irVoice.getLength());
            irSessionHistory.setAnswerVoiceId(irVoice.getId());
        }

        if (Objects.nonNull(robotTalkDTO.getAnswerInfo().getAnswerByte())
                || Objects.nonNull(robotTalkDTO.getAnswerInfo().getAnswerFile())) {
            // 如果返回的结果是字节，保存到文件表
            IrFile irFile = saveFileIfNoAbsent(robotTalkDTO.getAnswerInfo());
            if (Objects.nonNull(irFile)) {
                robotTalkDTO.getAnswerInfo().setContentType(3);
                robotTalkDTO.getAnswerInfo().setByteId(irFile.getId());
                irSessionHistory.setAnswerFileId(irFile.getId());
            }
        }
        // 写入对话日志
        sessionService.saveOrUpdate(irSessionHistory);
        robotTalkDTO.getAskInfo().setAskId(irSessionHistory.getId());
    }

    private IrVoice saveAudioIfNoAbsent(String message) {

        if (StrUtil.isEmpty(message)) {
            return null;
        }
        String translate = numberToChinese(message);
        TtsResultDTO resultDTO = voiceService.textToVoice(translate);
        IrVoice irVoice = new IrVoice();
        irVoice.setVoiceBase64(resultDTO.getAudio());
        if (NumberUtil.isNumber(resultDTO.getDuration())){
            irVoice.setLength(NumberUtil.parseInt(resultDTO.getDuration()));
        }
        irVoiceService.save(irVoice);
        return irVoice;
    }

    private QueryProcessDTO queryMatch2Answer(String sessionId, MatchQuestionAnswerDTO matchQuestionAnswerDTO,
                                              RobotTalkDTO robotTalkDTO, SuspectInfo suspectInfo) {
        QueryProcessDTO process = QueryProcessDTO.builder().state(2).build();
        if (Objects.nonNull(matchQuestionAnswerDTO) && robotTalkDTO.isDoNext()) {
            process = queryTemplateProcessor.process(matchQuestionAnswerDTO.getMatchQuestionCode(), sessionId,
                    ()->this.suspectInfo2IrSessionParam(sessionId,suspectInfo));
        }
        return process;
    }

    private List<IrSessionParam> suspectInfo2IrSessionParam(String sessionId,SuspectInfo suspectInfo) {
        List<IrSessionParam> sessionParams = new ArrayList<>();

        if (Objects.nonNull(suspectInfo)){
            sessionParams.add(new IrSessionParam(sessionId,"jykh",StrUtil.join(",",suspectInfo.getCardNumber())));
            sessionParams.add(new IrSessionParam(sessionId,"khrzjhm",suspectInfo.getIdNumber()));
            sessionParams.add(new IrSessionParam(sessionId,"khrmc",suspectInfo.getName()));
        }

        IrSessionParam sessionParam = irSessionParamService.lambdaQuery().eq(IrSessionParam::getSessionId, sessionId)
                .eq(IrSessionParam::getParamName, "ajid").one();
        if (Objects.nonNull(sessionParam)) {
            sessionParams.add(sessionParam);
        }
        return sessionParams;
    }

    private MatchQuestionAnswerDTO matchQuestionAnswer(String message) {

        if (StrUtil.isNotEmpty(message)){
            // 如果消息为空，则没必要进行意图匹配
            try {
                List<MatchQuestionAnswerDTO> matchQuestionAnswerDTOS = matchToolService.execMatch(message);
                log.info("问题:{} 匹配到的意图:{}", message, JSONUtil.toJsonStr(matchQuestionAnswerDTOS));
                return CollUtil.getFirst(matchQuestionAnswerDTOS);
            } catch (Exception e) {
                log.error("textTalk2Robot:内容:{} 相似度匹配失败", message,e);
                return null;
            }
        }
        return null;
    }

    private void extractInformation(String sessionId, String message, RobotTalkDTO robotTalkDTO) {
        ExtractInformationDTO extractInformationDTO = matchToolService.extractInformation(message);
        if (Objects.isNull(extractInformationDTO) || extractInformationDTO.allEmpty()) {
            return;
        }
        // 识别到重要信息
        IrSessionParam sessionParam = irSessionParamService.lambdaQuery().eq(IrSessionParam::getSessionId, sessionId).eq(IrSessionParam::getParamName, "ajid").one();
        AnswerInfo answerInfo = robotTalkDTO.getAnswerInfo();
        if (Objects.isNull(sessionParam) || StrUtil.isEmpty(sessionParam.getParamValue())) {
            // 案件id为空，需要设置案件id
            answerInfo.setContentType(2);
            answerInfo.setMessage("请先设置案件信息");
            robotTalkDTO.setDoNext(false);
        } else {
            Integer caseNo = StrUtil.isEmpty(sessionParam.getParamValue()) ? null : Integer.valueOf(sessionParam.getParamValue());
            List<SuspectInfo> suspectInfos = robotDataMapper.querySuspect(caseNo,
                    extractInformationDTO.getIdNumber(),
                    extractInformationDTO.getName(),
                    extractInformationDTO.getCardNumber());

            answerInfo.setContentType(6);
            SuspectInfo suspectInfo = Objects.isNull(CollUtil.getFirst(suspectInfos)) ?
                    extractInformation2Suspect(extractInformationDTO) : CollUtil.getFirst(suspectInfos);
            answerInfo.setSuspectInfo(suspectInfo);
            robotTalkDTO.setDoNext(false);
        }
    }

    private SuspectInfo extractInformation2Suspect(ExtractInformationDTO informationDTO) {

        SuspectInfo suspectInfo = new SuspectInfo();
        suspectInfo.setName(informationDTO.getName());
        suspectInfo.setIdNumber(informationDTO.getIdNumber());
        if (StrUtil.isNotEmpty(informationDTO.getCardNumber())){
            suspectInfo.setCardNumber(CollUtil.newArrayList(informationDTO.getCardNumber()));
        }
        return suspectInfo;
    }

    private static String decideAnswer(QueryProcessDTO process, IrRobotConfig config) {
        // 正确查询出结果
        if (Integer.valueOf(0).equals(process.getState())){
            if (Integer.valueOf(1).equals(process.getContentType()) ||
                    Integer.valueOf(6).equals(process.getContentType())){
                // 查询结果类型为字符串
                return process.getStringContent();
            }
        }
        // 参数异常或查询结果异常
        if (Integer.valueOf(1).equals(process.getState())){
            return StrUtil.join(",",process.paramCheckToMessage());
        }

        if (Integer.valueOf(2).equals(process.getState())){
            return config.getUnrecognizedOne();
        }
        return null;
    }

    private IrFile saveFileIfNoAbsent(AnswerInfo answerInfo) {
        if (Objects.isNull(answerInfo.getAnswerByte()) && Objects.isNull(answerInfo.getAnswerFile())){
            return null;
        }
        String fileType = Integer.valueOf(3).equals(answerInfo.getContentType()) ? "1" : "2";
        IrFile irFile = new IrFile();
        irFile.setFileType(fileType);
        irFile.setFileName("answer");
        if ("1".equals(irFile.getFileType())){
            irFile.setFileByte(answerInfo.getAnswerByte());
        }else {
            irFile.setFileByte(IoUtil.readBytes(FileUtil.getInputStream(answerInfo.getAnswerFile())));
            FileUtil.del(answerInfo.getAnswerFile());
        }
        irFile.setFileSize(irFile.getFileByte().length);
        irFile.setFileType(fileType);
        irFileService.save(irFile);
        return irFile;
    }


    private IrSessionHistory talk2SessionHistory(String sessionId, RobotTalkDTO robotTalkDTO,
                                                 MatchQuestionAnswerDTO matchQuestionAnswerDTO) {
        IrSessionHistory sessionHistory = new IrSessionHistory();
        sessionHistory.setId(robotTalkDTO.getAskInfo().getAskId());
        sessionHistory.setSessionId(sessionId);
        AnswerInfo answerInfo = robotTalkDTO.getAnswerInfo();
        sessionHistory.setAnswer(answerInfo.getMessage());
        sessionHistory.setAnswerType(answerInfo.getContentType());

        sessionHistory.setUserQuestion(robotTalkDTO.getAskInfo().getMessage());
        sessionHistory.setCreateUserId(UserUtil.getUser().getId());
        if (Objects.nonNull(matchQuestionAnswerDTO)){
            sessionHistory.setMatchKnowledgeId(matchQuestionAnswerDTO.getMatchQuestionCode());
            sessionHistory.setThreshold(BigDecimal.valueOf(matchQuestionAnswerDTO.getMatchScore()));
        }
        return sessionHistory;
    }

    @Override
    @Transactional(rollbackFor = Exception.class)
    public RobotTalkDTO videoTalk2Robot(MultipartFile multipartFile,RobotTalkReq robotTalkReq) {

        String sessionId = robotTalkReq.getSessionId();

        Assert.notEmpty(sessionId, "sessionId不能为空");
        Assert.notNull(multipartFile, "multipartFile不能为空");

        byte[] bytes = null;
        try {
            bytes = multipartFile.getBytes();
            String message = voiceService.voiceToText(bytes, sessionId);
            robotTalkReq.setMessage(message);
        } catch (IOException e) {
            log.error("语音转文字失败", e);
        }
        RobotTalkDTO robotTalkDTO = this.textTalk2Robot(robotTalkReq);
        robotTalkDTO.getAskInfo().setContentType(2);

        if (Objects.nonNull(bytes)){
            IrVoice irVoice = new IrVoice();
            irVoice.setVoiceBase64(Base64.encode(bytes));
            irVoiceService.save(irVoice);
            if (StrUtil.isNotEmpty(robotTalkDTO.getAskInfo().getAskId())){
                sessionService.lambdaUpdate()
                        .eq(IrSessionHistory::getId,robotTalkDTO.getAskInfo().getAskId())
                        .set(IrSessionHistory::getUserQuestionVoiceId,irVoice.getId()).update();
            }
        }

        return robotTalkDTO;
    }

    @Override
    public List<CommonDialogVo> talkList(String sessionId) {

        Assert.notEmpty(sessionId, "sessionId不能为空");
        List<IrSessionHistory> sessionHistoryList = sessionService.lambdaQuery().eq(IrSessionHistory::getSessionId, sessionId).orderBy(true, true,IrSessionHistory::getCreateTime).list();

        // 获取音频的长度
        List<String> voiceIds = sessionHistoryList.stream()
                .map(session -> CollUtil.toList(session.getAnswerVoiceId(), session.getUserQuestionVoiceId()))
                .flatMap(Collection::stream).filter(StrUtil::isNotEmpty).collect(Collectors.toList());
        Map<String, Integer> voiceLengthMap = CollUtil.isEmpty(voiceIds) ? new HashMap<>() :
                irVoiceService.listByIds(voiceIds).stream().filter(i->Objects.nonNull(i.getLength())).collect(Collectors.toMap(IrVoice::getId, IrVoice::getLength));

        return sessionHistoryList.stream().map(session->this.sessionHistory2RobotTalkDTO(session,voiceLengthMap))
                .filter(Objects::nonNull).flatMap(Collection::stream).collect(Collectors.toList());
    }

    private List<CommonDialogVo> sessionHistory2RobotTalkDTO(IrSessionHistory sessionHistory,Map<String, Integer> voiceLengthMap) {
        if (Objects.isNull(sessionHistory)){
            return null;
        }
        CommonDialogVo askDiaLog = CommonDialogVo.builder().dialogType(1)
                .dialogId(sessionHistory.getId()).sessionId(sessionHistory.getSessionId())
                .contentType(StrUtil.isEmpty(sessionHistory.getUserQuestionVoiceId()) ? 1 : 2)//userQuestionVoiceId 为空，则为1 否则为2
                .message(sessionHistory.getUserQuestion()).voiceBaseId(sessionHistory.getUserQuestionVoiceId())
                .audioLength(voiceLengthMap.get(sessionHistory.getUserQuestionVoiceId())).build();

        if (Integer.valueOf(6).equals(sessionHistory.getAnswerType())){
            // 屏蔽弹框记录
            return CollUtil.newArrayList(askDiaLog);
        }

        CommonDialogVo answerDiaLog = CommonDialogVo.builder().dialogType(2)
                .dialogId(sessionHistory.getId()).sessionId(sessionHistory.getSessionId())
                .contentType(sessionHistory.getAnswerType()).message(sessionHistory.getAnswer())
                .byteId(sessionHistory.getAnswerFileId()).voiceBaseId(sessionHistory.getAnswerVoiceId())
                .audioLength(voiceLengthMap.get(sessionHistory.getAnswerVoiceId()))
                .build();

        return CollUtil.toList(askDiaLog,answerDiaLog);
    }

    @Override
    public void getAudio(HttpServletResponse response, String audioId) throws IOException {
        Assert.notEmpty(audioId, "audioId不能为空");

        IrVoice voice = irVoiceService.getById(audioId);
        if (Objects.isNull(voice) || StrUtil.isEmpty(voice.getVoiceBase64())){
            return;
        }
        Base64.decodeToStream(voice.getVoiceBase64(), response.getOutputStream(),false);
    }

    @Override
    public void downLoadArchives(HttpServletResponse response,ArchivesReqVo archivesReq) throws IOException {
        String path =  localArchivesFilePath(archivesReq);
        if (StrUtil.isEmpty(path)){
            return;
        }
        IoUtil.copy(Files.newInputStream(Paths.get(path)),response.getOutputStream());
    }

    @Override
    public void downLoadFile(HttpServletResponse response, String fileType, String imageId) throws IOException {
        IrFile file = irFileService.getById(imageId);
        if (Objects.isNull(file) || Objects.isNull(file.getFileByte())){
            return;
        }

        if ("1".equals(file.getFileType())){
            IoUtil.write(response.getOutputStream(), true, Base64.decode(file.getFileByte()));
        }

        if ("2".equals(file.getFileType())){
            IoUtil.write(response.getOutputStream(), true,file.getFileByte());
        }

    }

    @Override
    public List<SuspectInfo> querySuspectInfo(String sessionId, String name) {

        Assert.notEmpty(sessionId, "sessionId不能为空");
        //Assert.notEmpty(name, "name不能为空");

        IrSessionParam sessionParam = irSessionParamService.lambdaQuery().eq(IrSessionParam::getSessionId, sessionId).eq(IrSessionParam::getParamName, "ajid").one();
        Assert.notNull(sessionParam, "未查询到案件");
        Assert.notEmpty(sessionParam.getParamValue(), "ajid不能为空");
        return robotDataMapper.querySuspect(NumberUtil.parseInt(sessionParam.getParamValue()), null, name, null);
    }

    private String localArchivesFilePath(ArchivesReqVo archivesReq) {
        String path = StrUtil.join(File.separator,archivesReq.getCaseId(),
                StrUtil.join("-",archivesReq.getName(),archivesReq.getIdNumber()),
                archivesReq.getDocumentId());

        // 判断文件是否存在
        if (FileUtil.exist(path)){
            return path;
        }
        return null;
    }

}