Spring Boot使用GridFS实现文件的上传和下载方式

sudo apt-get install mongodb

whereis mongofiles

mongofiles put /home/ubuntu/Desktop/ 1 .jpg

mongo

show dbs  # 发现多了一个gridfs

use gridfs

db.fs.files.find() # 存放文件的一些基本信息

db.fs.chunks.find() # 存放文件二进制内容，一个文件有多个fs.chunks，每个fs.chunks都有一个，files_id与fs.files中的id相对应，形成多对一的关系，文件存的时候分开存，取的时候再合并

< dependency >

  < groupId >org.springframework.boot</ groupId >

  < artifactId >spring-boot-starter-data-mongodb</ artifactId >

</ dependency >

< dependency >

  < groupId >commons-io</ groupId >

     < artifactId >commons-io</ artifactId >

     < version >2.4</ version >

</ dependency >

import com.mongodb.BasicDBObject;

import com.mongodb.DBObject;

import com.mongodb.client.gridfs.GridFSBucket;

import com.mongodb.client.gridfs.GridFSDownloadStream;

import com.mongodb.client.gridfs.GridFSFindIterable;

import com.mongodb.client.gridfs.model.GridFSFile;

import org.apache测试数据mons.io.IOUtils;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.data.mongodb.gridfs.GridFsOperations;

import org.springframework.data.mongodb.gridfs.GridFsResource;

import org.springframework.data.mongodb.gridfs.GridFsTemplate;

import org.springframework.http.MediaType;

import org.springframework.http.ResponseEntity;

import org.springframework.web.bind.annotation.*;

import org.springframework.web.multipart.MultipartFile;

import java.io.IOException;

import java.io.InputStream;

import static org.springframework.data.mongodb.core.query.Query.query;

import static org.springframework.data.mongodb.gridfs.GridFsCriteria.whereFilename;

@RestController

public class ImageController {

     @Autowired

     private GridFsTemplate gridFsTemplate;

     @Autowired

     private GridFsOperations operations;

     @Autowired

     private GridFSBucket gridFSBucket;

     @PostMapping ( "file/upload" )

     public ImageResponse upload( @RequestParam ( "file" ) MultipartFile file) {

         DBObject metaData = new BasicDBObject();

         // 把时间戳作为文件名存入mongodb

         String fileName = String.valueOf(System.currentTimeMillis());

         InputStream inputStream = null ;

         try {

             inputStream = file.getInputStream();

             gridFsTemplate.store(inputStream, fileName, "image" , metaData);

         } catch (IOException e) {

             throw new RuntimeException();

         }

         return new ImageResponse(fileName);

     }

     @GetMapping (value = "file/download/${fileName}" , produces = MediaType.IMAGE_JPEG_VALUE)

     @ResponseBody

     public byte [] getImage( @PathVariable ( "fileName" ) String fileName) throws IOException {

         if (fileName == null ) {

             return null ;

         }

         // 根据文件名查询(也可以根据md5值等信息查询)

         GridFSFindIterable result = operations.find(query(whereFilename().is(fileName)));

         GridFSFile gridFSFile = result.first();

         GridFSDownloadStream gridFSDownloadStream = gridFSBucket.openDownloadStream(gridFSFile.getObjectId());

         //创建gridFsResource，用于获取流对象

         GridFsResource gridFsResource = new GridFsResource(gridFSFile, gridFSDownloadStream);

         return IOUtils.toByteArray(gridFsResource.getInputStream());

     }

}

import com.mongodb.MongoClient;

import com.mongodb.client.MongoDatabase;

import com.mongodb.client.gridfs.GridFSBucket;

import com.mongodb.client.gridfs.GridFSBuckets;

import org.springframework.beans.factory.annotation.Value;

import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.Configuration;

@Configuration

public class MongoConfig {

     @Value ( "${spring.data.mongodb.database}" )

     String db;

     @Bean

     public GridFSBucket getGridFSBucket(MongoClient mongoClient){

         MongoDatabase database = mongoClient.getDatabase(db);

         GridFSBucket bucket = GridFSBuckets.create(database);

         return bucket;

     }

}

public class ImageResponse implements Serializable {

     private String imageName;

     public ImageResponse(String imageName) {

         this .imageName = imageName;

     }

     public String getImageName() {

         return imageName;

     }

     public void setImageName(String imageName) {

         this .imageName = imageName;

     }

}

spring:

   data:

     mongodb:

       uri: mongodb: //localhost:27017/gridfs

       database: gridfs

@Autowired

GridFsTemplate gridFsTemplate;

@Test

public void GridFsTest() throws FileNotFoundException {

    //选择要存储的文件

    File file = new File( "/Users/xxx/Desktop/xxx.docx" );

    InputStream inputStream = new FileInputStream(file);

    //存储文件并起名称

    ObjectId objectId = gridFsTemplate.store(inputStream, "面试宝典" );

    String id = objectId.toString();

    //获取到文件的id，可以从数据库中查找

    System.out.println(id);

}

@Configuration

public class MongoConfig {

     @Value ( "${spring.data.mongodb.database}" )

     String db;

     @Bean

     public GridFSBucket getGridFSBucket(MongoClient mongoClient){

         MongoDatabase mongoDatabase = mongoClient.getDatabase(db);

         GridFSBucket bucket = GridFSBuckets.create(mongoDatabase);

         return bucket;

     }

}

@Autowired

GridFsTemplate gridFsTemplate;

@Autowired

GridFSBucket gridFSBucket;

@Test

public void queryFile() throws IOException {

    String id = "5c1b8fac72884e389ae3df82" ;

    //根据id查找文件

    GridFSFile gridFSFile = gridFsTemplate.findOne( new Query(Criteria.where( "_id" ).is(id)));

    //打开下载流对象

    GridFSDownloadStream gridFS = gridFSBucket.openDownloadStream(gridFSFile.getObjectId());

    //创建gridFsSource，用于获取流对象

    GridFsResource gridFsResource = new GridFsResource(gridFSFile,gridFS);

    //获取流中的数据

    String string = IOUtils.toString(gridFsResource.getInputStream(), "UTF-8" );

    System.out.println(string);

}

//删除文件

@Test

public void testDelFile() throws IOException {

//根据文件id删除fs.files和fs.chunks中的记录

        gridFsTemplate.delete(Query.query(Criteria.where( "_id" ).is( "5c1b8fac72884e389ae3df82" )));

}