MongoDB图片上传下载 - GridFsTemplate

1、引入jar包

<!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-data-mongodb -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-mongodb</artifactId>
    <version>2.1.5.RELEASE</version>
</dependency>

2、yml 配置文件

spring:
  data:
    mongodb:
      uri: mongodb://192.168.124.217:27017/DocDB

# 这里 DocDB 是自己在mongoDB中创建的数据库，该配置是MongoDB无密码条件下的配置      
# spring.data.mongodb.uri=mongodb://name:pass@localhost:27017/test，其中name是用户名，pass是密码

3、业务代码

package com.ziumur.manager.web.rest;

import com.mongodb.client.MongoDatabase;
import com.mongodb.client.gridfs.GridFSBucket;
import com.mongodb.client.gridfs.GridFSBuckets;
import com.mongodb.client.gridfs.GridFSDownloadStream;
import com.mongodb.client.gridfs.model.GridFSFile;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import org.apache.commons.codec.binary.Base64;
import org.bson.types.ObjectId;
import org.h2.util.IOUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.annotation.Bean;
import org.springframework.data.mongodb.MongoDbFactory;
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.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

import javax.annotation.Resource;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URLEncoder;

/**
 * @ClassName： FileUploadController
 * @Description：
 * @author： 
 * @Date：2020/6/1 19:16
 **/
@Api(tags = "文件上传")
@Controller
@RequestMapping(value = "/api", produces = {
    
     MediaType.APPLICATION_JSON_VALUE })
public class UploadFileResource {
    
    

    private final Logger log = LoggerFactory.getLogger(FileUploadResource.class);


    private final GridFsTemplate gridFsTemplate;

    @Resource
    private MongoDbFactory mongoDbFactory;

    @Bean
    public GridFSBucket getGridFSBuckets() {
    
    
        MongoDatabase db = mongoDbFactory.getDb();
        return GridFSBuckets.create(db);
    }

    @Resource
    private GridFSBucket gridFSBucket;

    private static final String[] FILE_TYPES =
        new String[] {
    
    
            "jpg", "bmp", "jpeg", "png", "gif", "tif", "pcx", "tga", "exif", "exif", "svg",
            "psd", "cdr", "pcd", "dxf", "ufo", "eps", "ai", "raw", "WMF", "webp"
        };


    public UploadFileResource(GridFsTemplate gridFsTemplate) {
    
    
        this.gridFsTemplate = gridFsTemplate;
    }



    @ApiOperation(value = "上传图片", notes = "上传文件")
    @PostMapping(value = "uploadImage")
    public ResponseEntity<Object> uploadImage(@RequestParam("file") MultipartFile file) {
    
    
        String id = upload(file);
        return ResponseEntity.ok(id);
    }


    @ApiOperation(value = "下载图片", notes = "下载文件")
    @GetMapping(value = "downloadImage/{pictureGuid}")
    public void downloadImage(@PathVariable String pictureGuid, HttpServletResponse response)throws Exception {
    
    
         download(pictureGuid, response);

    }


    @ApiOperation(value = "显示图片", notes = "下载文件")
    @GetMapping(value = "getImage/{pictureGuid}")
    public void getImage(@PathVariable String pictureGuid, HttpServletResponse response)throws Exception {
    
    
        viewImg(pictureGuid, response);
    }

    private String upload(MultipartFile files) {
    
    
        //获取上传文件的原名
        String fileName = files.getOriginalFilename();
        String fileNameStr= Base64.encodeBase64String(fileName.getBytes());
        String[] split = fileName.split("\\.");
        //拿到文件后缀名
        String suff = split[split.length - 1];
        // 文件类型
        String save = "";
        try {
    
    
            ObjectId store = gridFsTemplate.store(files.getInputStream(), fileName, files.getContentType());
            String id = store.toString();
            if (StringUtils.hasLength(id)) save = id;
        } catch (IOException e) {
    
    
            e.printStackTrace();
            log.error(e.getMessage());
        }
        return save;
    }



    private void download(String fileId, HttpServletResponse response) {
    
    
        if (!StringUtils.hasLength(fileId)) {
    
    
            throw new RuntimeException("ID不能为空");
        }
        GridFSFile file = gridFsTemplate.findOne(Query.query(Criteria.where("_id").is(fileId)));
        if (null == file) {
    
    
            throw new RuntimeException("ID对应文件不存在");
        }
        String fileName = file.getFilename();
        //转成GridFsResource类取文件类型
        response.setContentType(convertGridFSFile2Resource(file).getContentType());
        try {
    
    
            // 解决文件名中文乱码
            response.setCharacterEncoding("UTF-8");
            fileName = URLEncoder.encode(fileName, "UTF-8");
            response.addHeader("Content-Disposition", "attachment; filename=\""+ fileName+"\"");
            //文件长度
            response.setHeader("Content-Length", String.valueOf(file.getLength()));
            OutputStream out = response.getOutputStream();
            //IO复制
            InputStream in=convertGridFSFile2Resource(file).getInputStream();
            IOUtils.copy(convertGridFSFile2Resource(file).getInputStream(), out);
        } catch (IOException e) {
    
    
            log.error(e.getMessage());
        }
        log.info("文件传输完成,退出方法");
    }



    private void viewImg(String fileId,
                        HttpServletResponse response) throws IOException {
    
    
        // 因为取出来的id带有后缀，因此做去除后缀处理
        if (fileId.contains(".")) {
    
    
            String[] split = fileId.split("\\.");
            fileId = split[0];
        }
        GridFSFile file = gridFsTemplate.findOne(Query.query(Criteria.where("_id").is(fileId)));
        if (null == file) {
    
    
            throw new RuntimeException("ID对应文件不存在");
        }
        String fileName = file.getFilename();
        OutputStream out = response.getOutputStream();
        //取后缀
        String contentType = (String)file.getMetadata().get("_contentType");
        String fileType= contentType.substring(contentType.lastIndexOf("/") + 1);
        boolean flag = false;
        for (String obj : FILE_TYPES) {
    
    
            if (fileType.equalsIgnoreCase(obj)) {
    
    
                flag = true;
                break;
            }
        }
        if (flag) {
    
    
            log.info("图片类型,进入预览");
            response.setHeader("Content-disposition", "inline; filename=" + fileName);
            response.setContentType(contentType);
            // 不进行压缩的文件大小，单位为bit
            int notCompressionBit = 512000;

            //大于512000bit就压缩，这里可以用压缩的方式，
         /*   if (file.getLength() > notCompressionBit) {
                Thumbnails.of(convertGridFSFile2Resource(file).getInputStream())
                    .scale(0.2f)
                    .outputQuality(0.5f)
                    .toOutputStream(out);
           }
         */
            /** 采用压缩方式，则需注释调这段代码-开始 **/
            //IO复制
            InputStream in=convertGridFSFile2Resource(file).getInputStream();
            int contentLength = (int)convertGridFSFile2Resource(file).contentLength();
            byte[] data = new byte[contentLength];
            in.read(data);
            //response here is the HttpServletResponse object
            response.setContentLength(contentLength);
            out.write(data);
            /** 采用压缩方式，则需注释调这段代码-结束 **/
            out.flush();
            out.close();
        } else {
    
    
            log.info("非图片类型,进入下载");
            //转成GridFsResource类取文件类型
            response.setContentType(convertGridFSFile2Resource(file).getContentType());
            response.setHeader("Content-Disposition", "attachment; filename=" + fileName);
            //文件长度
            response.setHeader("Content-Length", String.valueOf(file.getLength()));
            try {
    
    
                //IO复制
                InputStream in = convertGridFSFile2Resource(file).getInputStream();
                IOUtils.copy(
                    convertGridFSFile2Resource(file).getInputStream(), out);
            } catch (IOException e) {
    
    
                log.error(e.getMessage());
            }
        }
    }


    private GridFsResource convertGridFSFile2Resource(GridFSFile gridFsFile) {
    
    
        GridFSDownloadStream gridFSDownloadStream = gridFSBucket.openDownloadStream(gridFsFile.getObjectId());
        return new GridFsResource(gridFsFile, gridFSDownloadStream);
    }

}

4、测试

4.1 上传测试

 
采用 Swagger API 接口上传图片：

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调用该接口返回：

通过 MongoDB 可视化工具 Studio 3T 查看上传的文件：
 

 

4.2 显示接口测试

 

 

4.3 下载接口测试

 

 

 

5、缩略图补充说明

 
        对于显示和下载接口，可以对图片进行缩略操作，代码中已写，只是注释调了。采用缩略图功能，需要引入下面的 jar 包，
 

      <!--谷歌图片压缩组件-->
        <dependency>
            <groupId>net.coobird</groupId>
            <artifactId>thumbnailator</artifactId>
            <version>0.4.8</version>
        </dependency>