SpringBoot之文件上传 | 遇见你真好！

前言

针对thymeleaf对文件上传的方法进行总结，有不到之处敬请指正！

1.pom.xml依赖的编写

 <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-log4j2</artifactId>
            <version>2.6.3</version>
        </dependency>
    </dependencies>

2.application.yml配置文件的编写

# 端口
server:
  port: 8014

spring:
  application:
    # 应用名称
    name: node14-boot-file
  servlet:
    multipart:
      # 启用
      enabled: true
      # 上传文件单个限制
      max-file-size: 5MB
      # 总限制
      max-request-size: 6MB
  thymeleaf:
    cache:
      false  # 开发时关闭缓存,不然没法看到实时页面
    prefix:
      classpath: /templates # 访问template下的html文件需要配置模板，映射

3.templates下上传页面的编写

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<body>
<hr/>
<h3>1、单文件上传</h3>
<form method="POST" action="/upload1" enctype="multipart/form-data">
    上传人：<input type="text" name="userName" /><br/>
    文件一：<input type="file" name="file" /><br/>
    <input type="submit" value="Submit" />
</form>
<hr/>
<h3>2、多文件上传</h3>
<form method="POST" action="/upload2" enctype="multipart/form-data">
    上传人：<input type="text" name="userName" /><br/>
    文件一：<input type="file" name="file" /><br/>
    文件二：<input type="file" name="file" /><br/><br/>
    <input type="submit" value="Submit" />
</form>
</body>
</html>
<hr/>

4.文件上传控制器的编写

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;
import javax.servlet.http.HttpServletRequest;
import java.io.File;
import java.util.Map;

@RestController
public class FileController {

    private static final Logger LOGGER = LoggerFactory.getLogger(FileController.class) ;
    /**
     * 如果单个文件大小超出1MB，抛出异常
     * FileSizeLimitExceededException:
     * The field file exceeds its maximum permitted size of 1048576 bytes.
     */
    @RequestMapping("/upload1")
    public String upload1 (HttpServletRequest request, @RequestParam("file") MultipartFile file){
        Map<String, String[]> paramMap = request.getParameterMap() ;
        if (!paramMap.isEmpty()){
            LOGGER.info("paramMap == >>{}",paramMap);
        }
        try{
            if (!file.isEmpty()){
                // 打印文件基础信息
                LOGGER.info("Name == >>{}",file.getName());
                LOGGER.info("OriginalFilename == >>{}",file.getOriginalFilename());
                LOGGER.info("ContentType == >>{}",file.getContentType());
                LOGGER.info("Size == >>{}",file.getSize());
                // 文件输出地址
                String filePath = "D:\\boot-file\\" ;
                new File(filePath).mkdirs();
                File writeFile = new File(filePath, file.getOriginalFilename());
                file.transferTo(writeFile);
            }
            return "success" ;
        } catch (Exception e){
            e.printStackTrace();
            return "系统异常" ;
        }
    }

    /**
     * 如果上传文件总大小超过6MB，抛出异常
     * SizeLimitExceededException:
     * the request was rejected because its size (9052616) exceeds the configured maximum (6291456)
     */
    @RequestMapping("/upload2")
    public String upload2 (HttpServletRequest request, @RequestParam("file") MultipartFile[] fileList){
        Map<String, String[]> paramMap = request.getParameterMap() ;
        if (!paramMap.isEmpty()){
            LOGGER.info("paramMap == >>{}",paramMap);
        }
        try{
            if (fileList.length > 0){
                for (MultipartFile file:fileList){
                    // 打印文件基础信息
                    LOGGER.info("Name == >>{}",file.getName());
                    LOGGER.info("OriginalFilename == >>{}",file.getOriginalFilename());
                    LOGGER.info("ContentType == >>{}",file.getContentType());
                    LOGGER.info("Size == >>{}",file.getSize());
                    // 文件输出地址
                    String filePath = "D:\\boot-file\\" ;
                    new File(filePath).mkdirs();
                    File writeFile = new File(filePath, file.getOriginalFilename());
                    file.transferTo(writeFile);
                }
            }
            return "success" ;
        } catch (Exception e){
            return "fail" ;
        }
    }