SpringBoot 集成 MongoDB 实现文件上传下载

一个项目(本文是基于SpringBoot2.0.5项目环境下的操作)里面需要用到MongoDB 上传文件的操作，记录 一下开发的过程。另附一个使用swagger进行调试使用的小坑。

1.引入项目依赖(pom.xml)

  
        
            org.springframework.boot
            spring-boot-starter-data-mongodb
        

2.在application.yml配置文件中添加如下配置(这里dev为账号，123456为你的密码，作用的数据库为just,你需要提前设置一个账号并且创建一个数据库，让用户具有owner的权限)

spring:
  # mongodb的配置
  data:
    mongodb:
      uri: mongodb://dev:123456@localhost:27017/just

 

3.编写配置类MongoConf.java

package com.justcs.config;


import com.mongodb.client.MongoDatabase;
import com.mongodb.client.gridfs.GridFSBucket;
import com.mongodb.client.gridfs.GridFSBuckets;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.mongodb.MongoDbFactory;

/**
 * mongodb的配置类
 * 解决新版本不支持获取GGridFSDBFile
 */
@Configuration
public class MongoConf {

    @Autowired
    private MongoDbFactory mongoDbFactory;

    @Autowired
    private GridFSBucket gridFSBucket;


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

4.编写Controller测试类：

package com.justcs.controller;

import com.justcs.utils.JSONResult;
import com.mongodb.client.gridfs.GridFSBucket;
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.io.IOUtils;
import org.bson.types.ObjectId;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
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.Controller;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.net.URLEncoder;

/**
 * 文件上传下载控制类
 */
@Api(value = "文件上传下载控制类")
@Controller
@RequestMapping("/file")
public class MongoDBGFSController {

    private static final Logger logger = LoggerFactory.getLogger(MongoDBGFSController.class);

    @Autowired
    private GridFsTemplate gridFsTemplate;

    @Autowired
    private GridFSBucket gridFSBucket;


    /**
     * 上传文件
     *
     * @param file
     * @return
     * @throws IOException
     * @throws ServletException
     */
    @ApiOperation(value = "上传文件测试", notes = "上传文件测试demo")
    @PostMapping("upload")
    @ResponseBody
    public JSONResult uploadFile(@RequestParam("file") MultipartFile file) throws IOException, ServletException {
        // 获得提交的文件名
        String fileName = file.getOriginalFilename();
        // 获取文件输入流
        InputStream ins = file.getInputStream();
        // 获取文件类型
        String contentType = file.getContentType();
        // 将文件存储到mongodb中
        ObjectId objectId = gridFsTemplate.store(ins, fileName, contentType);
        logger.info("保存成功，objectId:" + objectId);
        return JSONResult.ok(objectId);
    }

    /**
     * 下载文件
     *
     * @param fileId
     * @param request
     * @param response
     * @throws IOException
     */
    @ApiOperation(value = "下载文件测试", notes = "下载文件测试demo")
    @RequestMapping(value = "/download", method = {RequestMethod.GET, RequestMethod.POST})
    public void downloadFile(@RequestParam(name = "file_id") String fileId,
                             HttpServletRequest request,
                             HttpServletResponse response) throws IOException {
        logger.info("准备下载文件....");
        Query query = Query.query(Criteria.where("_id").is(fileId));
        // 查询单个文件
        GridFSFile gridFSFile = gridFsTemplate.findOne(query);
        if (gridFSFile == null) {
            return;
        }

        String fileName = gridFSFile.getFilename().replace(",", "");
        String contentType = gridFSFile.getMetadata().get("_contentType").toString();

        // 通知浏览器进行文件下载
        response.setContentType(contentType);
        response.setHeader("Content-Disposition", "attachment;filename=\"" + URLEncoder.encode(fileName, "UTF-8") + "\"");
        GridFSDownloadStream gridFSDownloadStream = gridFSBucket.openDownloadStream(gridFSFile.getObjectId());
        GridFsResource resource = new GridFsResource(gridFSFile, gridFSDownloadStream);

        OutputStream outputStream = response.getOutputStream();
        InputStream inputStream = resource.getInputStream();
        IOUtils.copy(inputStream, outputStream);
        outputStream.flush();
        outputStream.close();
        inputStream.close();
    }

}

5.让项目跑起来，这里我用的是swagger来进行调试的(使用前后端分离的方式来开发)

测试上传文件：

成功上传（这里我使用的mongodb的可视化工具Studio 3T）：

测试下载文件：（敲黑板了！重点问题来了，一定不要点swagger返回的文件下载链接，而是要自己重新复制一个连接在浏览器访问才能正确下载文件，否则你得到的文件是有问题的，或者根本打不开！）

而是在浏览器中访问：