导读

由于需要上传图片，这里列举了文件上传的步骤。

使用步骤

添加依赖

<dependency>
     <groupId>commons-io</groupId>
     <artifactId>commons-io</artifactId>
     <version>2.6</version>
</dependency>

修改配置文件application.yml

spring:
  servlet:
    multipart:
      enabled: true
      max-file-size: 50MB
      max-request-size: 50MB

注：这里文件大小要大写的MB，如果是小写的Mb会报错。

或者修改对应的application.properties

# 最大支持文件大小
spring.servlet.multipart.max-file-size=50MB
# 最大支持请求大小
spring.servlet.multipart.max-request-size=50MB
# 下方可加可不加
#默认支持文件上传
spring.servlet.multipart.enabled=true
#支持文件写入磁盘.
spring.servlet.multipart.file-size-threshold=0
# 上传文件的临时目录
spring.servlet.multipart.location=

定义一个model类

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import java.io.Serializable;
/**
 * 处理后上传文件的信息
 */
@Data
@NoArgsConstructor
@AllArgsConstructor
public class UploadInfo implements Serializable {
    private static final long serialVersionUID = -2088268852466393733L;
    /**
     * 上传结果
     */
    private String result;
    /**
     * 初始文件名
     */
    private String beginFileName;
    /**
     * 最终上传文件名
     */
    private String lastFileName;
    /**
     * 文件类型
     */
    private String fileType;
    /**
     * 文件大小
     */
    private String fileSize;
    /**
     * 文件上传的地址
     */
    private String uploadUrl;
}

创建Controller层

import com.ck.model.UploadInfo;
import com.ck.service.IndexService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.MediaType;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.multipart.MultipartFile;
import java.util.Map;
@Controller
@RequestMapping("/app")
public class IndexController {
    @Autowired
    private IndexService uploadService;
    private final static String UPLOAD_FILE_PATH = "G:\\cksso\\resources\\upfile";
    /**
     *上传文件测试
     */
    @PostMapping(value = "/uploadFile", consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
    @ResponseBody
    public UploadInfo uploadTest(@RequestParam("file") MultipartFile file) {
        UploadInfo uploadInfo = null;
        try {
            uploadInfo = uploadService.upload(file, UPLOAD_FILE_PATH);
        } catch (Exception e) {
            System.out.println(e.toString());
        }
        return uploadInfo;
    }
}

注：方法前需要加入注解@ResponseBody不然会出现_Error resolving template "xxx", template might not exist or might not be accessible by any of the configured Template Resolvers_错误。

创建Service定义接口

import com.ck.model.UploadInfo;
import org.springframework.web.multipart.MultipartFile;
public interface IndexService {
    /**
     * 文件上传接口
     * @param file 文件名称
     * @param uploadFilePath 文件上传到服务器路径
     * @return 
     * @throws Exception
     */
    UploadInfo upload(MultipartFile file, String uploadFilePath) throws Exception;
}

创建Service实现层

import com.ck.model.UploadInfo;
import com.ck.service.IndexService;
import org.springframework.stereotype.Service;
import org.springframework.web.multipart.MultipartFile;
import java.io.File;
import java.util.UUID;
@Service
public class IndexServiceImpl implements IndexService {
    @Override
    public UploadInfo upload(MultipartFile file, String uploadFilePath) throws Exception {
        if (file.isEmpty()) {
            return null;
        }
        UploadInfo uploadInfo = new UploadInfo();
        String originalFilename;
        String fileName;
        originalFilename = file.getOriginalFilename();
        //为了防止上传的图片重复，这里使用UUID来处理
        fileName = UUID.randomUUID().toString() + file.getOriginalFilename();
        String fileType = fileName.substring(fileName.lastIndexOf(".") + 1);
        long fileSize = file.getSize();
        File packageFile = new File(uploadFilePath);
        if (!packageFile.exists()) {
            packageFile.mkdir();
        }
        File targetFile = new File(uploadFilePath + "/" + fileName);
        //调用该方法实现文件上传
        file.transferTo(targetFile);
        uploadInfo.setBeginFileName(originalFilename);
        uploadInfo.setLastFileName(fileName);
        uploadInfo.setFileType(fileType);
        uploadInfo.setFileSize(Long.toString(fileSize));
        uploadInfo.setUploadUrl(targetFile.toString());
        uploadInfo.setResult("文件上传成功");
        return uploadInfo;
    }
}

创建前台Thymeleaf页面

<body>
<form action="/app/uploadFile" method="POST" enctype="multipart/form-data">
    <input type="file" name="file"><br>
    <input type="submit" value="上传文件">
</form>
</body>

页面如下图所示：

结果测试

通过浏览器访问，在选择相应文件后点击上传，会出现以下响应结果，并且在项目的upfile文件夹能找到上传的文件，则表明成功上传。

项目中的upfile文件夹：

参考

• Springboot文件上传到FTP服务器
• SpringBoot实现文件上传
• SpringBoot实现多文件上传