springboot实现文件上传与下载

1、jsp

上传功能：

<tr class="main_table_tr">
    <td class="td_title"><p class="add_table_p2">附件：</p></td>
    <td>
        <input type="text" id="attach_file" name="attach_file" class="td_input" value="${bean.attach_file}"
               placeholder="点击选择文件" onclick="javascript:$('input[name=\'inputFile\']').click();" readonly style="width: 844px;"/>
        <input type="file" id="inputFile" name="inputFile" style="display:none;"
               onchange="javascript:$('input[name=\'attach_file\']').val(this.files[0].name);"/>
        <input type="button" value="上传" onclick="uploadFile();" />
    </td>
</tr>

下载功能：

<a href="<%=path %>/file/download?fileName=${bean.attach_file }">${bean.attach_file }</a>

2、JAVA后台

package com.csg.scarmknowledge.controller;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.multipart.MultipartHttpServletRequest;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.util.List;

/**
 * 文件上传下载
 */
@Controller
@RequestMapping("/file")
public class FileController {

    private Logger log = LoggerFactory.getLogger(FileController.class);

    /**
     * 单文件上传
     * @param multipartHttpServletRequest
     * @return
     */
    @RequestMapping(value = "/upload")
    @ResponseBody
    public String upload(HttpServletRequest request, MultipartHttpServletRequest multipartHttpServletRequest) {
        // 获取上传文件的路径
        MultipartFile uploadFile = multipartHttpServletRequest.getFile("file");
        String uploadFilePath = "";
        if (uploadFile != null) {
            uploadFilePath = uploadFile.getOriginalFilename();
            System.out.println("uploadFlePath:" + uploadFilePath);
        } else {
            return "2";
        }
        // 截取上传文件的文件名
        String uploadFileName = uploadFilePath.substring(uploadFilePath.lastIndexOf('\\') + 1, uploadFilePath.indexOf('.'));
        System.out.println("multiReq.getFile()" + uploadFileName);
        // 截取上传文件的后缀
        String uploadFileSuffix = uploadFilePath.substring(uploadFilePath.indexOf('.') + 1, uploadFilePath.length());
        System.out.println("uploadFileSuffix:" + uploadFileSuffix);
        FileOutputStream fos = null;
        FileInputStream fis = null;
        try {
            fis = (FileInputStream) multipartHttpServletRequest.getFile("file").getInputStream();
            fos = new FileOutputStream(new File("E:\\uploadFiles\\" + uploadFileName + ".") + uploadFileSuffix);
            byte[] temp = new byte[1024];
            int i = fis.read(temp);
            while (i != -1){
                fos.write(temp,0,temp.length);
                fos.flush();
                i = fis.read(temp);
            }
            return "1";
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (fis != null) {
                try {
                    fis.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (fos != null) {
                try {
                    fos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return "0";
    }

    /**
     * 文件下载
     * @param fileName
     * @param response
     * @return
     */
    @GetMapping("/download")
    @ResponseBody
    public void downloadFile(@RequestParam("fileName") String fileName,HttpServletResponse response) throws UnsupportedEncodingException {
        String filePath = "E:\\uploadFiles" ;
        File file = new File(filePath + "/" + fileName);
        if(file.exists()){ //判断文件父目录是否存在
            response.setContentType("application/vnd.ms-excel;charset=UTF-8");
            response.setCharacterEncoding("UTF-8");
            // response.setContentType("application/force-download");
            response.setHeader("Content-Disposition", "attachment;fileName=" +   java.net.URLEncoder.encode(fileName,"UTF-8"));
            byte[] buffer = new byte[1024];
            FileInputStream fis = null; //文件输入流
            BufferedInputStream bis = null;

            OutputStream os = null; //输出流
            try {
                os = response.getOutputStream();
                fis = new FileInputStream(file);
                bis = new BufferedInputStream(fis);
                int i = bis.read(buffer);
                while(i != -1){
                    os.write(buffer);
                    i = bis.read(buffer);
                }

            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            System.out.println("----------file download---" + fileName);
            try {
                bis.close();
                fis.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }
}