Spring Boot使用GridFS實現文件的上傳和下載方式

sudo apt-get install mongodb

whereis mongofiles

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

mongo
show dbs  # 發現多瞭一個gridfs
use gridfs
db.fs.files.find() # 存放文件的一些基本信息
db.fs.chunks.find() # 存放文件二進制內容，一個文件有多個fs.chunks，每個fs.chunks都有一個，files_id與fs.files中的id相對應，形成多對一的關系，文件存的時候分開存，取的時候再合並

<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.commons.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();
        // 把時間戳作為文件名存入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;
        }
        // 根據文件名查詢(也可以根據md5值等信息查詢)
        GridFSFindIterable result = operations.find(query(whereFilename().is(fileName)));
        GridFSFile gridFSFile = result.first();
        GridFSDownloadStream gridFSDownloadStream = gridFSBucket.openDownloadStream(gridFSFile.getObjectId());
        //創建gridFsResource，用於獲取流對象
        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 {
   //選擇要存儲的文件
   File file = new File("/Users/xxx/Desktop/xxx.docx");
   InputStream inputStream = new FileInputStream(file);
   //存儲文件並起名稱
   ObjectId objectId = gridFsTemplate.store(inputStream, "面試寶典");
   String id = objectId.toString();
   //獲取到文件的id，可以從數據庫中查找
   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";
   //根據id查找文件
   GridFSFile gridFSFile = gridFsTemplate.findOne(new Query(Criteria.where("_id").is(id)));
   //打開下載流對象
   GridFSDownloadStream gridFS = gridFSBucket.openDownloadStream(gridFSFile.getObjectId());
   //創建gridFsSource，用於獲取流對象
   GridFsResource gridFsResource = new GridFsResource(gridFSFile,gridFS);
   //獲取流中的數據
   String string = IOUtils.toString(gridFsResource.getInputStream(), "UTF-8");
   System.out.println(string);
}

 //刪除文件
@Test
public void testDelFile() throws IOException {
//根據文件id刪除fs.files和fs.chunks中的記錄
       gridFsTemplate.delete(Query.query(Criteria.where("_id").is("5c1b8fac72884e389ae3df82")));
}