spring boot+thymeleaf 文件上传，下载功能实现

1，pom.xml文件添加thymeleaf依赖

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

properties文件设置thymeleaf

# thymeleaf
spring.thymeleaf.prefix=classpath:/templates/
spring.thymeleaf.check-template-location=true
spring.thymeleaf.suffix=.html
spring.thymeleaf.encoding=UTF-8
spring.thymeleaf.content-type=text/html
spring.thymeleaf.mode=HTML5
spring.thymeleaf.cache=false

server.port=8082

# Single file max size
spring.servlet.multipart.max-file-size=100MB
# All files max size
spring.servlet.multipart.max-request-size=100MB

2，controller类

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
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;

@Controller
public class FileUploadController {

    /*
     * 获取file.html页面
     */
    @RequestMapping("file")
    public String file(){
        return "/file";
    }

    /**
     * 实现文件上传
     * */
    @RequestMapping("fileUpload")
    @ResponseBody
    public String fileUpload(@RequestParam("fileName") MultipartFile file){
        if(file.isEmpty()){
            return "false";
        }
        String fileName = file.getOriginalFilename();
        int size = (int) file.getSize();
        System.out.println(fileName + "-->" + size);

        String path = "F:/test" ;
        File dest = new File(path + "/" + fileName);
        if(!dest.getParentFile().exists()){ //判断文件父目录是否存在
            dest.getParentFile().mkdir();
        }
        try {
            file.transferTo(dest); //保存文件
            return "true";
        } catch (IllegalStateException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            return "false";
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            return "false";
        }
    }
    /*
     * 获取multifile.html页面
     */
    @RequestMapping("multifile")
    public String multifile(){
        return "/multifile";
    }

    /**
     * 实现多文件上传
     * */
    @RequestMapping(value="multifileUpload",method= RequestMethod.POST)
/**public @ResponseBody String multifileUpload(@RequestParam("fileName")List<MultipartFile> files) */
    public @ResponseBody String multifileUpload(HttpServletRequest request){

        List<MultipartFile> files = ((MultipartHttpServletRequest)request).getFiles("fileName");

        if(files.isEmpty()){
            return "false";
        }

        String path = "F:/test" ;

        for(MultipartFile file:files){
            String fileName = file.getOriginalFilename();
            int size = (int) file.getSize();
            System.out.println(fileName + "-->" + size);

            if(file.isEmpty()){
                return "false";
            }else{
                File dest = new File(path + "/" + fileName);
                if(!dest.getParentFile().exists()){ //判断文件父目录是否存在
                    dest.getParentFile().mkdir();
                }
                try {
                    file.transferTo(dest);
                }catch (Exception e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                    return "false";
                }
            }
        }
        return "true";
    }

    @RequestMapping("download")
    public String download(){
        return "/download";
    }
    //文件下载
    @RequestMapping("downLoadFile")
    public String downLoadFile(HttpServletResponse response) throws UnsupportedEncodingException {
        String filename="22.jpg";//此处应该选择公共区域的文件，下载到本地
        String filePath = "F:/test" ;
        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();
            }
        }
        return null;
    }
}

3，html代码如下:

file.html 单个文件上传

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:th="http://www.thymeleaf.org" xmlns:sec="http://www.thymeleaf.org/thymeleaf-extras-springsecurity3">
<head>
    <meta charset="UTF-8" />
    <title>文件上传</title>
</head>
<body>
<h1 th:inlines="text">文件上传</h1>
<form action="fileUpload" method="post" enctype="multipart/form-data">
    <p>选择文件: <input type="file" name="fileName"/></p>
    <p><input type="submit" value="提交"/></p>
</form>
</body>
</html>

4，上传结果

返回true即上传成功

多个软件上传和下载在源码 这里