文章摘要
这篇文章介绍了基于MongoDB和Spring Boot实现的文件管理服务。该服务实现了上传、下载和删除文件的功能。上传时，根据文件大小选择存储在MongoDB本地或GridFS中；下载时，从GridFS或本地存储获取文件，并在下载完成后自动删除对应的存储文件。文章还涉及了依赖注入、流式处理、文件后缀处理以及对MongoDB和GridFS的操作，体现了对MongoDB存储结构和GridFS存储策略的优化处理。核心功能包括文件上传、下载和删除，支持高效的大文件管理。
import cn.hutool.core.io.IoUtil;
import cn.hutool.core.util.IdUtil;
import com.coisini.mongodb.model.MongoFile;
import com.coisini.mongodb.repository.MongoFileRepository;
import com.coisini.mongodb.service.FileUploadService;
import com.coisini.mongodb.util.MD5Util;
import com.coisini.mongodb.vo.FileExportVo;
import com.mongodb.client.gridfs.GridFSBucket;
import com.mongodb.client.gridfs.GridFSDownloadStream;
import com.mongodb.client.gridfs.model.GridFSFile;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.bson.types.Binary;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.data.mongodb.core.query.Criteria;
import org.springframework.data.mongodb.core.query.Query;
import org.springframework.data.mongodb.gridfs.GridFsResource;
import org.springframework.data.mongodb.gridfs.GridFsTemplate;
import org.springframework.stereotype.Service;
import org.springframework.web.multipart.MultipartFile;
import java.io.IOException;
import java.io.InputStream;
import java.util.Date;
import java.util.List;
import java.util.Objects;
import java.util.Optional;
import java.util.stream.Collectors;
@Slf4j
@Service(“fileMongoServiceImpl”)
@RequiredArgsConstructor(onConstructor=@__(@Autowired))
public class FileMongoServiceImpl implements FileUploadService {
private final MongoFileRepository mongoFileRepository;
private final MongoTemplate mongoTemplate;
private final GridFsTemplate gridFsTemplate;
private final GridFSBucket gridFSBucket;
@Override
public List<FileExportVo> uploadFiles(List<MultipartFile> files) {
return files.stream().map(file -> {
try {
return this.uploadFile(file);
} catch (Exception e) {
log.error(“文件上传失败”, e);
return null;
}
}).filter(Objects::nonNull).collect(Collectors.toList());
}
@Override
public FileExportVo uploadFile(MultipartFile file) throws Exception {
if (file.getSize() > 16777216) {
return this.saveGridFsFile(file);
} else {
return this.saveBinaryFile(file);
}
}
@Override
public FileExportVo downloadFile(String fileId) {
Optional<MongoFile> option=this.getBinaryFileById(fileId);
if (option.isPresent()) {
MongoFile mongoFile=option.get();
if(Objects.isNull(mongoFile.getContent())){
option=this.getGridFsFileById(fileId);
}
}
return option.map(FileExportVo::new).orElse(null);
}
@Override
public void removeFile(String fileId) {
Optional<MongoFile> option=this.getBinaryFileById(fileId);
if (option.isPresent()) {
if (Objects.nonNull(option.get().getGridFsId())) {
this.removeGridFsFile(fileId);
} else {
this.removeBinaryFile(fileId);
}
}
}
public void removeBinaryFile(String fileId) {
mongoFileRepository.deleteById(fileId);
}
public void removeGridFsFile(String fileId) {
// TODO 根据id查询文件
MongoFile mongoFile=mongoTemplate.findById(fileId, MongoFile.class );
if(Objects.nonNull(mongoFile)){
// TODO 根据文件ID删除fs.files和fs.chunks中的记录
Query deleteFileQuery=new Query().addCriteria(Criteria.where(“filename”).is(mongoFile.getGridFsId()));
gridFsTemplate.delete(deleteFileQuery);
// TODO 删除集合mongoFile中的数据
Query deleteQuery=new Query(Criteria.where(“id”).is(fileId));
mongoTemplate.remove(deleteQuery, MongoFile.class);
}
}
public FileExportVo saveBinaryFile(MultipartFile file) throws Exception {
String suffix=getFileSuffix(file);
MongoFile mongoFile=mongoFileRepository.save(
MongoFile.builder()
.fileName(file.getOriginalFilename())
.fileSize(file.getSize())
.content(new Binary(file.getBytes()))
.contentType(file.getContentType())
.uploadDate(new Date())
.suffix(suffix)
.md5(MD5Util.getMD5(file.getInputStream()))
.build()
);
return new FileExportVo(mongoFile);
}
public FileExportVo saveGridFsFile(MultipartFile file) throws Exception {
String suffix=getFileSuffix(file);
String gridFsId=this.storeFileToGridFS(file.getInputStream(), file.getContentType());
MongoFile mongoFile=mongoTemplate.save(
MongoFile.builder()
.fileName(file.getOriginalFilename())
.fileSize(file.getSize())
.contentType(file.getContentType())
.uploadDate(new Date())
.suffix(suffix)
.md5(MD5Util.getMD5(file.getInputStream()))
.gridFsId(gridFsId)
.build()
);
return new FileExportVo(mongoFile);
}
public String storeFileToGridFS(InputStream in, String contentType){
String gridFsId=IdUtil.simpleUUID();
// TODO 将文件存储进GridFS中
gridFsTemplate.store(in, gridFsId , contentType);
return gridFsId;
}
public Optional<MongoFile> getBinaryFileById(String id) {
return mongoFileRepository.findById(id);
}
public Optional<MongoFile> getGridFsFileById(String id){
MongoFile mongoFile=mongoTemplate.findById(id , MongoFile.class );
if(Objects.nonNull(mongoFile)){
Query gridQuery=new Query().addCriteria(Criteria.where(“filename”).is(mongoFile.getGridFsId()));
try {
// TODO 根据id查询文件
GridFSFile fsFile=gridFsTemplate.findOne(gridQuery);
// TODO 打开流下载对象
GridFSDownloadStream in=gridFSBucket.openDownloadStream(fsFile.getObjectId());
if(in.getGridFSFile().getLength() > 0){
// TODO 获取流对象
GridFsResource resource=new GridFsResource(fsFile, in);
// TODO 获取数据
mongoFile.setContent(new Binary(IoUtil.readBytes(resource.getInputStream())));
return Optional.of(mongoFile);
}else {
return Optional.empty();
}
}catch (IOException e){
log.error(“获取MongoDB大文件失败”, e);
}
}
return Optional.empty();
}
private String getFileSuffix(MultipartFile file) {
String suffix=””;
if (Objects.requireNonNull(file.getOriginalFilename()).contains(“.”)) {
suffix=file.getOriginalFilename().substring(file.getOriginalFilename().lastIndexOf(“.”));
}
return suffix;
}
}