springboot实现文件上传的功能

通过上面这个图，头像只能上传一个，生活照就可以上传多个文件

看一下upload.html

<div class="panel-body">
                        <form role="form" th:action="@{/upload}" method="post" enctype="multipart/form-data">
                            <div class="form-group">
                                <label for="exampleInputEmail1">邮箱</label>
                                <input type="email" name="email"  class="form-control" id="exampleInputEmail1" placeholder="Enter email">
                            </div>
                            <div class="form-group">
                                <label for="exampleInputPassword1">名字</label>
                                <input type="text" name="username"  class="form-control" id="exampleInputPassword1" placeholder="Password">
                            </div>
                            <div class="form-group">
                                <label for="exampleInputFile">头像</label>
                                <input type="file" name="headerImg" id="exampleInputFile">
                                <p class="help-block">Example block-level help text here.</p>
                            </div>
                            <div class="form-group">
                                <label for="exampleInputFile">生活照</label>
                                 <input type="file" name="photos" multiple>
                            </div>
                            <div class="checkbox">
                                <label>
                                    <input type="checkbox"> Check me out
                                </label>
                            </div>
                            <button type="submit" class="btn btn-primary">Submit</button>
                        </form>

                    </div>

比较重要的就是：

<form role="form" th:action="@{/upload}" method="post" enctype="multipart/form-data">
指定了上传路径，因为要上传东西所以需要用post方式

单文件上传
<label for="exampleInputFile">头像</label>
 <input type="file" name="headerImg" id="exampleInputFile">

多文件上传，最后加上 multiple就可以
 <label for="exampleInputFile">生活照</label>
  <input type="file" name="photos" multiple>

后端的实现代码

@PostMapping("/upload")
    public String upload(@RequestParam("email") String email,
                         @RequestParam("username") String username,
                         @RequestPart("headerImg")MultipartFile hearderImg,
                         @RequestPart("photos") MultipartFile[] photos) throws IOException {
        log.info("上传的信息:email={} ,username={},hearderImg={},photos={}",email,username,hearderImg.getSize(),photos.length);
        if(!hearderImg.isEmpty()){
            String originalFilename=hearderImg.getOriginalFilename();
            hearderImg.transferTo(new File("E:\\cache\\"+originalFilename));
        }
        if(photos.length>0){
            for(MultipartFile photo : photos){
                if(!photo.isEmpty()){
                    String  originalname=photo.getOriginalFilename();
                    photo.transferTo(new File(""+originalname));
                }
            }
        }
        return "main";

    }

需要注意的就是

@RequestParam("username") String username,
@RequestPart("headerImg")MultipartFile hearderImg,
图片部分用的是 RequestPart不一样

 String originalFilename=hearderImg.getOriginalFilename();
获取上传文件的名字
 hearderImg.transferTo(new File("E:\\cache\\"+originalFilename));
指定保存的路径
if(photos.length>0){
            for(MultipartFile photo : photos){
                if(!photo.isEmpty()){
                    String  originalname=photo.getOriginalFilename();
                    photo.transferTo(new File(""+originalname));
                }
            }
        }
这是因为上传多个图片所以需要进行遍历