grails将文件插入mongodb数据库

首先建立一个Domain class类。代码如下所示：

import com.mongodb.WriteConcernimport org.bson.types.ObjectIdclass FileItem {    static mapWith = "mongo"    static constraints = {    }    static mapping = {        writeConcern WriteConcern.FSYNC_SAFE    }    ObjectId id    String fileName         //文件名    String fileType         //文件类型    Long fileSize           //文件大小    String fileDescription  //文件描述    String fsId             //FSGrid存储ID    Date dateCreated //创建日期    Date lastUpdated //最后修改日期    String createdBy //创建人    String updatedBy //最后修改人}

接下来需要一个公共类，将任何类型的本地文件都可以自动存入到数据库中去。

Service类如下所示：

import com.mongodb.gridfs.GridFSimport com.mongodb.gridfs.GridFSDBFileimport com.mongodb.gridfs.GridFSInputFileimport org.bson.types.ObjectId/** * 文件管理服务 * 通过Mongo GRIDFS 服务提供文件的存储 * 通过FileItem表记录真实文件名与GRID FS ID的关联 */class FileMgmtService {    static transactional = false    def mongo    def grailsApplication    def securityService    /**     * 上传文件保存到集中存储的地方     * @return     */    FileItem saveFile(String fileName, byte[] fileData, String contentType, String fileDescription) {        //存储GridFS数据库        GridFS gridFS = new GridFS(mongo.getDB(grailsApplication.config.grails.mongo.databaseName))        GridFSInputFile gridFSInputFile = gridFS.createFile(fileData)        gridFSInputFile.filename = fileName        gridFSInputFile.contentType = contentType        gridFSInputFile.save()        //存储FileItem表        FileItem fileItem = new FileItem()        fileItem.fileDescription = fileDescription        fileItem.fileName = fileName        fileItem.createdBy = securityService.currentUserName        fileItem.dateCreated = new Date()        fileItem.fileSize = fileData.size()        fileItem.fileType = contentType        fileItem.fsId = gridFSInputFile.id.toString()        fileItem.save(flush: true, validate: false)        return fileItem    }    //删除文件必须通过该服务，同时删除FileItem和GridFS文件    void deleteFile(String fileItemId) {        FileItem fileItem = FileItem.findById(new ObjectId(fileItemId))        if(fileItem){            GridFS gridFS = new GridFS(mongo.getDB(grailsApplication.config.grails.mongo.databaseName))            gridFS.remove(new ObjectId(fileItem.fsId))            fileItem.delete()        }    }    //获取真正文件数据    byte[] getFileData(String fileItemId) {        FileItem fileItem = FileItem.findById(new ObjectId(fileItemId))        if(fileItem){            ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream()            GridFS gridFS = new GridFS(mongo.getDB(grailsApplication.config.grails.mongo.databaseName))            GridFSDBFile gridFSDBFile = gridFS.find(new ObjectId(fileItem.fsId))            if(gridFSDBFile){                gridFSDBFile.writeTo(byteArrayOutputStream)            }            return byteArrayOutputStream.toByteArray()        }else{            return null        }    }}

读取数据库中如果有国际化文件，则必须读取环境中相应的语言类型，然后进行选择。

def getCurrentLocale() {        try {            def lang = RequestContextHolder.currentRequestAttributes().getSession().'org.springframework.web.servlet.i18n.SessionLocaleResolver.LOCALE'.language            if (lang) {                if (lang.startsWith('en')) {                    return ParameterConstant.LOCALE_EN_US                }  else if (lang && lang.startsWith('zh')) {                    return ParameterConstant.LOCALE_ZH_CN                }            } else {                return ParameterConstant.LOCALE_EN_US            }        } catch (Throwable e) {            return ParameterConstant.LOCALE_EN_US        }    }