springboot 上传文件

核心控制器

package com.neo.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.servlet.mvc.support.RedirectAttributes;

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

@Controller
public class UploadController {
    //上传路径
    private static String UPLOADED_FOLDER = "D:/upload/";

    //单文件上传页面
    @GetMapping("/")
    public String index() {
        return "upload";
    }

    //多文件上传页面
    @GetMapping("/more")
    public String uploadMore() {
        return "uploadMore";
    }

    //单文件上传接口
    @PostMapping("/upload")
    public String singleFileUpload(@RequestParam("file") MultipartFile file,
                                   RedirectAttributes redirectAttributes) {
        if (file.isEmpty()) {
            redirectAttributes.addFlashAttribute("message", "Please select a file to upload");
            return "redirect:uploadStatus";
        }
        try {
            byte[] bytes = file.getBytes();
            Path path = Paths.get(UPLOADED_FOLDER + file.getOriginalFilename());
            Files.write(path, bytes);

            redirectAttributes.addFlashAttribute("message",
                    "You successfully uploaded '" + file.getOriginalFilename() + "'");
        } catch (IOException e) {
            e.printStackTrace();
        }
        return "redirect:/uploadStatus";
    }

    //多文件上传接口
    @PostMapping("/uploadMore")
    public String moreFileUpload(@RequestParam("file") MultipartFile[] files,
                                   RedirectAttributes redirectAttributes) {
        if (files.length==0) {
            redirectAttributes.addFlashAttribute("message", "Please select a file to upload");
            return "redirect:uploadStatus";
        }
        for(MultipartFile file:files){
            try {
                byte[] bytes = file.getBytes();
                Path path = Paths.get(UPLOADED_FOLDER + file.getOriginalFilename());
                Files.write(path, bytes);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        redirectAttributes.addFlashAttribute("message", "You successfully uploaded all");
        return "redirect:/uploadStatus";
    }
    
    //文件上传成功页面
    @GetMapping("/uploadStatus")
    public String uploadStatus() {
        return "uploadStatus";
    }

}

配置application.properties

#http://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#common-application-properties
#search multipart
spring.servlet.multipart.max-file-size=10MB
spring.servlet.multipart.max-request-size=10MB

其他相关配置：

• spring.servlet.multipart.enabled=true，是否⽀持 multipart 上传⽂件
• spring.servlet.multipart.file-size-threshold=0，⽀持⽂件写⼊磁盘
• spring.servlet.multipart.location=，上传⽂件的临时⽬录
• spring.servlet.multipart.max-file-size=10Mb，最⼤⽀持⽂件⼤⼩
• spring.servlet.multipart.max-request-sizee=10Mb，最⼤⽀持请求⼤⼩
• spring.servlet.multipart.resolve-lazily=false，是否⽀持 multipart 上传⽂件时懒加载
  

单文件上传表单

<form method="POST" action="/upload" enctype="multipart/form-data">
    <input type="file" name="file" /><br/><br/>
    <input type="submit" value="Submit" />
</form>

多文件上传表单

<form method="POST" action="/uploadMore" enctype="multipart/form-data">
    文件1： <input type="file" name="file" /><br/><br/>
    文件2： <input type="file" name="file" /><br/><br/>
    文件3： <input type="file" name="file" /><br/><br/>
    <input type="submit" value="Submit" />
</form>