文件上传和下载

package com.yujie.controller;

import com.yujie.service.UploadOrDownloadFileService;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

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

@RestController
public class UploadOrDownloadFileController {
    @Autowired
    private UploadOrDownloadFileService fileService;

    @RequestMapping("/upload")
    public String uploadFile(MultipartFile[] upload, HttpServletRequest request, HttpServletResponse response) throws IOException {
      fileService.uploadFile(upload,request,response);
        return "success";
    }

    @RequestMapping("/downloadWebFile")
    public String downloadWebFile(HttpServletRequest request, HttpServletResponse response){
        String url="https://mirrors.aliyun.com/centos/7/isos/x86_64/CentOS-7-x86_64-DVD-2207-02.iso?spm=a2c6h.25603864.0.0.36142d1c0EDuvc";
        fileService.downloadWebFile(url,request,response);
        return "ok";
    }

    @RequestMapping("/downloadLocalFile")
    public String downloadLocal(HttpServletRequest request, HttpServletResponse response){
        fileService.downloadLocal("D:\\testsql.sql",request,response);
        return "ok";
    }


}

public interface UploadOrDownloadFileService {
    public String downloadLocal (String fileName, HttpServletRequest request, HttpServletResponse response);
    public String downloadWebFile(String url, HttpServletRequest request, HttpServletResponse response);
    public String uploadFile(MultipartFile[] upload, HttpServletRequest request, HttpServletResponse response);
}

Service
public class UploadOrDownloadFileServiceImpl implements UploadOrDownloadFileService {
    @Override
    public String downloadLocal(String filePath, HttpServletRequest request, HttpServletResponse response) {
        try {
            FileUtil.downloadLocal(filePath,request,response);
        } catch (ClientAbortException e) {
            System.out.println("客户端已取消下载");
        }catch (Exception e){
            e.printStackTrace();
        }
        return "ok";
    }


    /**
     * 下载的外网文件
     * @param urlPath
     * @param request
     * @param response
     * @return
     */
    @Override
    public String downloadWebFile(String urlPath, HttpServletRequest request, HttpServletResponse response) {
        try {
            FileUtil.downloadWeb(urlPath,request,response);
        } catch (ClientAbortException e) {
            System.out.println("客户端已取消下载");
        }catch (Exception e){
            e.printStackTrace();
        }
        return "ok";
    }

    @Override
    public String uploadFile(MultipartFile[] upload, HttpServletRequest request, HttpServletResponse response) {
        String path = request.getSession().getServletContext().getRealPath("/uploads/");
        File file = new File(path);
        if(!file.exists()){
            file.mkdirs();
        }
        String filename = UUID.randomUUID().toString().replaceAll("-","");
        try {
            upload[0].transferTo(new File(path,filename+upload[0].getOriginalFilename()));
        } catch (IOException e) {
            e.printStackTrace();
        }
        return "ok";
    }

}

package com.yujie.utils;



import org.apache.catalina.connector.ClientAbortException;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLEncoder;

public class FileUtil {

    public static void downloadLocal(String filePath,HttpServletRequest request, HttpServletResponse response) throws Exception{
        File file = new File(filePath);
        if(!file.exists()){
            throw new FileNotFoundException("不存在文件:"+filePath);
        }
        FileInputStream fileInputStream = new FileInputStream(file);
        ServletOutputStream out = response.getOutputStream();

        try {
            //设置响应类型
            String mimeType=request.getServletContext().getMimeType(filePath);
            response.setHeader("Content-Type",mimeType);
            String filename = URLEncoder.encode(file.getName(), "utf-8");
            response.setHeader("Content-disposition","attachment;filename="+filename);
            response.setHeader("Content-Length" , String.valueOf(file.length()));

            byte[] buffer = new byte[1024];
            int bytesRead=0;
            while ((bytesRead = fileInputStream.read(buffer)) != -1) {
                out.write(buffer, 0, bytesRead);
            }
        } catch (ClientAbortException e){
            throw e;
        }catch (Exception e){
            throw e;
        }finally {
            fileInputStream.close();
        }

    }

    /**
     * 下载web文件
     * @param urlPath 外网文件地址
     * @param request
     * @param response
     * @throws IOException
     */
    public static void downloadWeb (String urlPath,HttpServletRequest request, HttpServletResponse response) throws Exception {
        URLConnection urlConnection = new URL(urlPath).openConnection();
        InputStream inputStream = urlConnection.getInputStream();
        ServletOutputStream out = response.getOutputStream();

        //获取url文件名
        String name = urlPath.substring(urlPath.lastIndexOf("/")+1);
        //设置响应类型
        String mimeType=request.getServletContext().getMimeType(urlPath);
        response.setHeader("Content-Type",mimeType);
        String filename = URLEncoder.encode(name, "utf-8");

        response.setHeader("Content-disposition","attachment;filename="+filename);
        String fileSize = urlConnection.getHeaderField("Content-Length");
        if(fileSize!=null && fileSize.length()!=0 && !fileSize.equals("0")){
            response.setHeader("Content-Length" , fileSize);
        }

        byte[] buffer = new byte[1024];
        int bytesRead=0;

        try {
            while ((bytesRead = inputStream.read(buffer)) != -1) {
                out.write(buffer, 0, bytesRead);
            }
        }catch (ClientAbortException e){
            throw e;
        }catch (Exception e){
            throw e;
        }finally {
            inputStream.close();
        }

    }

}