SpringBoot实现服务器端文件上传下载

代码：

1：controller

package com.peraglobal.business.file.controller;

import com.peraglobal.business.file.domain.vo.FileVO;
import com.peraglobal.business.file.service.FileService;
import com.peraglobal.common.util.R;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import io.swagger.annotations.ApiParam;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@Api(tags = "文件服务")
@RestController
@RequestMapping("/file")
public class FileController {

    @Resource
    private FileService fileService;

    @ApiOperation("文件上传")
    @PostMapping("/upload")
    public R<FileVO> uploadFile(@ApiParam("文件流") MultipartFile file,
                                HttpServletRequest request) throws IOException {
        return fileService.upload(file, request);
    }

    @ApiOperation("文件下载")
    @PostMapping("/download")
    public void downloadFile(HttpServletRequest request,
                                            HttpServletResponse response) throws IOException {
        fileService.downloadFile(request, response);
    }
}

2:service

        

package com.peraglobal.business.file.service;

import com.peraglobal.business.file.domain.vo.FileVO;
import com.peraglobal.common.util.R;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public interface FileService {

    /**
     * 文件上传
     * @param file
     * @param request
     * @return
     */
    R<FileVO> upload(MultipartFile file, HttpServletRequest request) throws IOException;

    /**
     * 文件下载
     * @param request
     * @return
     */
    void downloadFile(HttpServletRequest request, HttpServletResponse response) throws IOException;
}

 3:impl 

package com.peraglobal.business.file.service.impl;

import com.peraglobal.business.file.domain.vo.FileVO;
import com.peraglobal.business.file.service.FileService;
import com.peraglobal.common.util.ChainUtil;
import com.peraglobal.common.util.R;
import lombok.extern.slf4j.Slf4j;
import org.apache.http.HttpHeaders;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.http.MediaType;
import org.springframework.stereotype.Service;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.net.URLEncoder;
import java.nio.ByteBuffer;
import java.nio.channels.Channel;
import java.nio.channels.Channels;
import java.nio.channels.ReadableByteChannel;
import java.nio.channels.WritableByteChannel;


@Slf4j
@Service
public class FileServiceImpl implements FileService {

   
    private static String localPath = "D:/file";

    private static final int BUFFER_SIZE = 10*1024;

    @Override
    public R<FileVO> upload(MultipartFile file, HttpServletRequest request) throws IOException {
        FileVO fileVO = new FileVO();
        if(file == null){
            return R.failed("文件为空");
        }
        FileOutputStream fileOutputStream = null;
        String dateId = ChainUtil.getDateId();
        String originalFilename = file.getOriginalFilename();
        String s = dateId +"_"+ originalFilename;
        String filePath = localPath+"/"+ s;
        File upFile = new File(filePath);
        if( ! upFile.exists()){
            upFile.createNewFile();
        }
        byte[] bytes = file.getBytes();
        try {
            fileOutputStream = new FileOutputStream(upFile);
            fileOutputStream.write(bytes);
        }catch (Exception e){
            log.error("文件上传失败", e);
        }finally {
            if(fileOutputStream != null){
                fileOutputStream.flush();
                fileOutputStream.close();
            }
        }
        fileVO.setFileName(s);
        fileVO.setFilePath("/toolchain/file/"+s);
        return R.ok(fileVO);
    }


    @Override
    public void downloadFile(HttpServletRequest request, HttpServletResponse response) throws IOException {
        String fileName = "20231211173212linux命令.txt";
        String filePath = localPath+"/"+ fileName;
        File file = new File(filePath);
        if(!file.exists()){

        }
        InputStream inputStream = new BufferedInputStream(new FileInputStream(filePath));
        response.setHeader(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_OCTET_STREAM_VALUE);
        response.setContentType(MediaType.APPLICATION_OCTET_STREAM_VALUE);
        String fileName2 = URLEncoder.encode(fileName);
        response.setHeader("Content-Disposition", "attachment;filename=" + fileName2 + ";" + "filename*=utf-8''" + fileName2);
        ReadableByteChannel src = null;
        WritableByteChannel dest = null;
        ByteBuffer buffer2 = ByteBuffer.allocate(BUFFER_SIZE);
        try {
            src = Channels.newChannel(inputStream);
            dest = Channels.newChannel(response.getOutputStream());
            while ((src.read(buffer2)) > 0) {
                buffer2.flip();
                dest.write(buffer2);
                buffer2.compact();
            }
            src.close();
            dest.close();
        } catch (IOException e) {
            e.printStackTrace();
            log.error(e.getMessage());
        }finally {
            closeChanel(src);
            closeChanel(dest);
        }
    }


    /**
     * 关闭流
     * @param channel
     */
    private static void closeChanel(Channel channel){
        if(channel != null){
            try {
                channel.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

4:返回VO

package com.peraglobal.business.file.domain.vo;

import lombok.Data;


@Data
public class FileVO {

    private String fileName;

    private String filePath;
}

5：说明

R为我自己定义的返回对象，每个人的返回不同根据自己需求定义，可以返回JSONObject或者String，代码就不放上去了

 调用

1：上传

可以看到上传成功。

2：下载

根据上传的文件名下载，后台写死了，自己根据需求修改业务逻辑。