SpringBoot 中使用 MongoDb 上传文件

概述

什么是 MongoDb

MongoDB 是由C++语言编写的,是一个基于分布式文件存储的开源数据库系统。

在高负载的情况下,添加更多的节点,可以保证服务器性能。

MongoDB 旨在为WEB应用提供可扩展的高性能数据存储解决方案。

MongoDB 将数据存储为一个文档,数据结构由键值(key=>value)对组成。MongoDB 文档类似于 JSON 对象。字段值可以包含其他文档,数组及文档数组。

MongoDB GridFS

GridFS 用于存储和恢复那些超过16M(BSON文件限制)的文件(如:图片、音频、视频等)。

GridFS 也是文件存储的一种方式,但是它是存储在MonoDB的集合中。

GridFS 可以更好的存储大于16M的文件。

GridFS 会将大文件对象分割成多个小的chunk(文件片段),一般为256k/个,每个chunk将 作为MongoDB的一个文档(document)被存储在chunks集合中。

GridFS 用两个集合来存储一个文件:fs.files与fs.chunks。

每个文件的实际内容被存在chunks(二进制数据)中,和文件有关的meta数据(filename,content_type,还有用户自定义的属性)将会被存在files集合中。

以下是简单的 fs.files 集合文档:

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{
"filename": "test.txt",
"chunkSize": NumberInt(261120),
"uploadDate": ISODate("2014-04-13T11:32:33.557Z"),
"md5": "7b762939321e146569b07f72c62cca4f",
"length": NumberInt(646)
}

以下是简单的 fs.chunks 集合文档:

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{
"files_id": ObjectId("534a75d19f54bfec8a2fe44b"),
"n": NumberInt(0),
"data": "Mongo Binary Data"
}

MongoDB 下载

Maven 项目结构

spring-boot-demo
│  .gitignore
│  pom.xml
│  spring-boot-demo.iml
│
└─spring-boot-mongodb
│  .gitignore
│  pom.xml
│  spring-boot-mongodb.iml
│
├─src
│  ├─main
│  │  ├─java
│  │  │  └─com
│  │  │      └─example
│  │  │          └─mongodb
│  │  │              │  SpringBootMongodbApplication.java
│  │  │              │
│  │  │              ├─controller
│  │  │              │      MongoFileController.java
│  │  │              │
│  │  │              └─utils
│  │  │                      MongoFileUtils.java
│  │  │
│  │  └─resources
│  │          application.properties
│  │
│  └─test
│      └─java
│          └─com
│              └─example
│                  └─mongodb
│                          SpringBootMongodbApplicationTests.java

Pom.xml 依赖配置

  • spring-boot-demo 项目配置
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<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.7.2</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<packaging>pom</packaging>

<modules>
<module>spring-boot-mongodb</module>
</modules>

<groupId>com.example</groupId>
<artifactId>spring-boot-demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>spring-boot-demo</name>
<description>spring-boot-demo</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>

<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
</dependencies>

<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<excludes>
<exclude>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</exclude>
</excludes>
</configuration>
</plugin>
</plugins>
</build>

</project>
  • spring-boot-mongodb 子模块配置
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<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>com.example</groupId>
<artifactId>spring-boot-demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<artifactId>spring-boot-mongodb</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>spring-boot-mongodb</name>
<description>spring-boot-mongodb</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<!-- 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>2.7.2</version>
</dependency>
</dependencies>

</project>

Application.properties 配置

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server.port = 8088
spring.profiles.active=default

spring.data.mongodb.uri=mongodb://localhost:27017/GridFS
spring.data.mongodb.database=GridFS
spring.data.mongodb.host=localhost
spring.data.mongodb.port=27017
spring.data.mongodb.username=
spring.data.mongodb.password=

控制器

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package com.example.mongodb.controller;

import com.example.mongodb.utils.MongoFileUtils;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletResponse;

/**
* The type Mongo file controller.
*
* @author loquy
*/
@RestController
@RequestMapping(value = "/mongoFile")
public class MongoFileController {

/**
* 上传文件
*
* @param multipartFile the multipart file
* @return the string
*/
@PostMapping("/upload")
public String uploadFile(@RequestParam("file") MultipartFile multipartFile) {
String originFilename = multipartFile.getOriginalFilename();
String fileId;
try {
fileId = MongoFileUtils.uploadFileToGridFs(StringUtils.getFilename(originFilename), multipartFile.getInputStream());
} catch (Exception e) {
e.printStackTrace();
return "上传失败," + e.getMessage();
}
return "上传成功,文件ID:" + fileId;
}

/**
* 删除文件
*
* @param fileId the file id
* @return the string
*/
@PostMapping("/remove")
public String removeFile(@RequestParam("fileId") String fileId) {
try {
MongoFileUtils.deleteByObjectId(fileId);
} catch (Exception e) {
e.printStackTrace();
return "删除失败," + e.getMessage();
}

return "删除成功";
}

/**
* 显示图片
*
* @param fileId the file id
* @param response the response
*/
@GetMapping(value = "/showImage/{fileId}")
public Object showImage(@PathVariable(name = "fileId") String fileId, HttpServletResponse response) {
try {
MongoFileUtils.showImage(fileId, response);
} catch (Exception e) {
e.printStackTrace();
return "显示失败," + e.getMessage();
}

return "";
}

/**
* 下载附件
*
* @param fileId the file id
* @param response the response
*/
@GetMapping(value = "/download/{fileId}")
public Object download(@PathVariable(name = "fileId") String fileId, HttpServletResponse response) {
try {
MongoFileUtils.downloadFile(fileId, response);
} catch (Exception e) {
e.printStackTrace();
return "下载失败," + e.getMessage();
}
return "";
}
}

工具类

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package com.example.mongodb.utils;

import com.mongodb.client.MongoClient;
import com.mongodb.client.MongoClients;
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 org.bson.types.ObjectId;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

import javax.servlet.http.HttpServletResponse;
import java.io.InputStream;
import java.io.OutputStream;


/**
* The type Mongo file utils.
*
* @author loquy
*/
@Component
public class MongoFileUtils {

private static String database;

/**
* Sets database.
*
* @param database the database
*/
@Value("${spring.data.mongodb.database}")
public void setDatabase(String database) {
MongoFileUtils.database = database;
}

/**
* Gets database.
*
* @return the database
*/
public static MongoDatabase getMongoDatabase() {
MongoClient mongoClient = MongoClients.create();
return mongoClient.getDatabase(database);
}

/**
* Upload file to grid fs string.
*
* @param filename the filename
* @param in the in
* @return the string
* @throws Exception the exception
*/
public static String uploadFileToGridFs(String filename, InputStream in) throws Exception {
GridFSBucket bucket = GridFSBuckets.create(getMongoDatabase());
ObjectId fileId = bucket.uploadFromStream(filename, in);
in.close();
return fileId.toHexString();
}

/**
* Download to stream.
*
* @param objectId the object id
* @param out the out
*/
public static void downloadToStream(String objectId, OutputStream out) {
GridFSBucket bucket = GridFSBuckets.create(getMongoDatabase());
bucket.downloadToStream(new ObjectId(objectId), out);
}

/**
* Download file.
*
* @param objectId the object id
* @param response the response
* @throws Exception the exception
*/
public static void downloadFile(String objectId, HttpServletResponse response) throws Exception {
OutputStream os;
String outFileName = findFileNameById(objectId);
response.setHeader("content-disposition", "attachment;filename=" + java.net.URLEncoder.encode(outFileName, "UTF-8"));
os = response.getOutputStream();
downloadToStream(objectId, os);
os.close();
}

/**
* Show image.
*
* @param objectId the object id
* @param response the response
* @throws Exception the exception
*/
public static void showImage(String objectId, HttpServletResponse response) throws Exception {
response.setContentType("image/jpeg");
OutputStream out = response.getOutputStream();
downloadToStream(objectId, out);
out.flush();
out.close();
}

/**
* Delete by object id.
*
* @param objectId the object id
*/
public static void deleteByObjectId(String objectId) {
GridFSBucket bucket = GridFSBuckets.create(getMongoDatabase());
bucket.delete(new ObjectId(objectId));
}

/**
* Find file name by id string.
*
* @param objectId the object id
* @return the string
*/
public static String findFileNameById(String objectId) {
GridFSBucket bucket = GridFSBuckets.create(getMongoDatabase());
GridFSDownloadStream stream;
stream = bucket.openDownloadStream(new ObjectId(objectId));
GridFSFile file = stream.getGridFSFile();
return file.getFilename();
}
}

测试

上传文件

下载文件

显示图片

删除文件

源码

参见此仓库


SpringBoot 中使用 MongoDb 上传文件
http://www.loquy.cn/e153eef8.html
作者
loquy
发布于
2022年7月28日
许可协议