SpringBoot-（十一）SpringBoot实现文件上传

本文最后更新于：February 16, 2022 pm

SpringBoot框架中有两个非常重要的策略：开箱即用和约定优于配置。其设计目的是用来简化新Spring应用的初始搭建以及开发过程。该框架使用了特定的方式来进行配置，从而使开发人员不再需要定义样板化的配置。

目录

准备

用到Hutool的工具：

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<dependency>
    <groupId>cn.hutool</groupId>
    <artifactId>hutool-all</artifactId>
    <version>5.7.20</version>
</dependency>
<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>4.1.2</version>
</dependency>

数据库：

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CREATE TABLE `file` (
  `id` int NOT NULL AUTO_INCREMENT,
  `name` varchar(255) DEFAULT NULL COMMENT '文件名称',
  `type` varchar(30) DEFAULT NULL,
  `size` bigint DEFAULT NULL, # 存储kb
  `url` varchar(255) DEFAULT NULL,
  `is_delete` tinyint(1) DEFAULT '0', # 是否删除，默认0为没删除
  `enable` tinyint(1) DEFAULT '0', # 链接是否可以访问，默认0为可以访问
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=10 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci

设置文件上传的位置

在主配置文件中：

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files: # 上传文件的位置
  upload:
    path: F:/idea2022Test/home/files/

上传

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package com.tothefor.controller;

import cn.hutool.core.io.FileUtil;
import cn.hutool.core.util.IdUtil;
import cn.hutool.core.util.StrUtil;
import com.tothefor.dao.FilesMapper;
import com.tothefor.pojo.entity.Files;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

import javax.annotation.Resource;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.IOException;
import java.net.URLEncoder;

@RestController
@RequestMapping("/file")
public class FileController {

    @Value("${files.upload.path}")
    private String fileUploadPath;

    @Resource
    private FilesMapper fileMapper;


    /**
     * 文件上传
     * @param file
     * @return
     * @throws IOException
     */
    @PostMapping("/upload")
    public String upload(@RequestParam MultipartFile file) throws IOException {
        String odername = file.getOriginalFilename(); //原始名称
        String type = FileUtil.extName(odername); //通过hutool工具类获取类型
        long size =file.getSize();

        File uploadParentFile = new File(fileUploadPath);

        if(!uploadParentFile.exists()){ //配置的文件目录是否存在，不存在则创建
            uploadParentFile.mkdirs();
        }
        //定义文件唯一标识码
        String uuid = IdUtil.fastSimpleUUID();
        String fileuuid = uuid+StrUtil.DOT+type;//重命名
        File uploadFile = new File(fileUploadPath+fileuuid);
        //将上传并处理后的文件进行存储到指定位置
        file.transferTo(uploadFile);

        String url = "http://localhost:8081/file/"+fileuuid;

        Files myfile = new Files();
        myfile.setName(odername);
        myfile.setType(type);
        myfile.setSize(size/1024); //从b转化为kb
        myfile.setUrl(url);
        fileMapper.insert(myfile); //文件mapper，insert是插入数据

        return url;
    }


}

下载

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package com.tothefor.controller;

import cn.hutool.core.io.FileUtil;
import cn.hutool.core.util.IdUtil;
import cn.hutool.core.util.StrUtil;
import com.tothefor.dao.FilesMapper;
import com.tothefor.pojo.entity.Files;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

import javax.annotation.Resource;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.IOException;
import java.net.URLEncoder;

@RestController
@RequestMapping("/file")
public class FileController {

    @Value("${files.upload.path}")
    private String fileUploadPath;

    @Resource
    private FilesMapper fileMapper;

    /**
     * http://localhost:8081/file/{fileuuid}
     * @param fileuuid
     * @param response
     * @throws IOException
     */
    @GetMapping("/{fileuuid}")
    public void download(@PathVariable String fileuuid, HttpServletResponse response) throws IOException {
        //根据文件的唯一标识码获取文件
        File uploadFile = new File(fileUploadPath+fileuuid); //重命名
        //设置输出流的格式
        ServletOutputStream os = response.getOutputStream();
        response.addHeader("Content-Disposition","attachment;filename="+ URLEncoder.encode(fileuuid,"UTF-8"));
        response.setContentType("application/octet-stream");

        // 读取文件字节流
        os.write(FileUtil.readBytes(uploadFile));
        os.flush();
        os.close();
    }

}

完整上传和下载

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package com.tothefor.controller;

import cn.hutool.core.io.FileUtil;
import cn.hutool.core.util.IdUtil;
import cn.hutool.core.util.StrUtil;
import com.tothefor.dao.FilesMapper;
import com.tothefor.pojo.entity.Files;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

import javax.annotation.Resource;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.IOException;
import java.net.URLEncoder;

@RestController
@RequestMapping("/file")
public class FileController {

    @Value("${files.upload.path}")
    private String fileUploadPath;

    @Resource
    private FilesMapper fileMapper;


    /**
     * 文件上传
     * @param file
     * @return
     * @throws IOException
     */
    @PostMapping("/upload")
    public String upload(@RequestParam MultipartFile file) throws IOException {
        String odername = file.getOriginalFilename(); //原始名称
        String type = FileUtil.extName(odername); //通过hutool工具类获取类型
        long size =file.getSize();

        File uploadParentFile = new File(fileUploadPath);

        if(!uploadParentFile.exists()){ //配置的文件目录是否存在，不存在则创建
            uploadParentFile.mkdirs();
        }
        //定义文件唯一标识码
        String uuid = IdUtil.fastSimpleUUID();
        String fileuuid = uuid+StrUtil.DOT+type;//重命名
        File uploadFile = new File(fileUploadPath+fileuuid);
        //将上传并处理后的文件进行存储到指定位置
        file.transferTo(uploadFile);

        String url = "http://localhost:8081/file/"+fileuuid; //此处的file是设置url，而不是文件存储位置的files，即：应该写访问此controller的主RequestMapping路径

        Files myfile = new Files();
        myfile.setName(odername);
        myfile.setType(type);
        myfile.setSize(size/1024); //从b转化为kb
        myfile.setUrl(url);
        fileMapper.insert(myfile);

        return url;
    }

    /**
     * http://localhost:8081/file/{fileuuid}
     * @param fileuuid
     * @param response
     * @throws IOException
     */
    @GetMapping("/{fileuuid}")
    public void download(@PathVariable String fileuuid, HttpServletResponse response) throws IOException {
        //根据文件的唯一标识码获取文件
        File uploadFile = new File(fileUploadPath+fileuuid); //重命名
        //设置输出流的格式
        ServletOutputStream os = response.getOutputStream();
        response.addHeader("Content-Disposition","attachment;filename="+ URLEncoder.encode(fileuuid,"UTF-8"));
        response.setContentType("application/octet-stream");

        // 读取文件字节流
        os.write(FileUtil.readBytes(uploadFile));
        os.flush();
        os.close();
    }

}

文件去重

通过MD5识别。