Spring Boot 文件上传

1. 修改SpringBoot默认文件上传大小

servlet:
    multipart:
      max-file-size: 10MB

2. 设置Spring Boot内置tomcat虚拟路径

@Configuration
public class WebConfig implements WebMvcConfigurer {

    /**
     * 虚拟路径配置
     * @param registry
     */
    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/upload/**").addResourceLocations("file:F:/tomcat-upload/");
    }
}

3. 文件上传类

import lombok.Data;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletRequest;
import java.io.File;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.UUID;

@Data
public class UploadUtil {
    //源文件名
    private String originalFilename;

    //源文件后缀名
    private String suffix;

    //存入数据库里的tomcat虚拟路径
    private String dbPath;

    //文件大小
    private long size;

    //实际存储路径
    private String realPath;

    /**
     * 文件上传工具类
     * @param attach
     * @param request
     * @param uploader 文件上传者
     * @return
     */
    public boolean doUpload(MultipartFile attach, HttpServletRequest request, String uploader){

        if(!attach.isEmpty()){

            originalFilename = attach.getOriginalFilename();
            System.out.println("==>上传的文件名："+originalFilename);

            suffix = originalFilename.substring(originalFilename.lastIndexOf("."));
            System.out.println("==>上传的文件后缀名："+suffix);

            size = attach.getSize();
            System.out.println("==>上传文件的大小："+size);

            String currentFilename = System.currentTimeMillis()+ UUID.randomUUID().toString() + suffix;
            System.out.println("==>存储的上传文件名："+currentFilename);

            realPath = "F:/tomcat-upload"+request.getContextPath() +"/" + uploader + "/" + new SimpleDateFormat("yyyy-MM-dd").format(new Date());
            System.out.println("==>上传文件保存的真实路径："+realPath);

            File targetFile = new File(realPath, currentFilename);
            if(!targetFile.exists()){
                targetFile.mkdirs();
            }

            try{
                attach.transferTo(targetFile);
            }catch (Exception e){
                e.printStackTrace();
                return false;
            }
            realPath = realPath + "/" + currentFilename;
            dbPath = "/upload" + request.getContextPath() + "/" + uploader + "/" + new SimpleDateFormat("yyyy-MM-dd").format(new Date()) + "/" + currentFilename;
            return true;
        }else{
            return false;
        }

    }
}

4. 前端上传页面

<form th:action="@{/controller-url}" method="post" enctype="multipart/form-data">
    <input type="file" name="file"/><br><br>
    <input type="submit" value="Upload"/>
    <p style="color: red" th:text="${#request.getAttribute('msg')}"></p>
</form>

5. 控制器

/**
     * 测试单文件上传
     * @param file
     * @param request
     * @param session
     * @return
     */
@PostMapping("/controller-url")
public String testUpload(@RequestParam(value = "file",required = false)MultipartFile file,HttpServletRequest request,HttpSession session){

    UploadUtil uploadUtil = new UploadUtil();

    //从session域中获取上传用户
    String uploader = ((User)(session.getAttribute("currentUser"))).getUsername();
    if(uploadUtil.doUpload(file,request,uploader)){       
        //处理上传逻辑
        request.setAttribute("msg","上传成功！");
    }else{
        request.setAttribute("msg","上传失败！");
    }

    return "view-url";
}