SpringMvc通过controller上传文件代码示例

　　上传文件这个功能用的比较多，不难，但是每次写都很别扭。记录在此，以备以后copy用。

package com.**.**.**.web.api;

import io.swagger.annotations.ApiOperation;
import org.apache.commons.lang.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.multipart.MultipartHttpServletRequest;

import javax.servlet.http.HttpServletRequest;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.URL;

/**
 * @Author: zyydd
 * @Date: 2019/10/12 14:18
 */
@RestController
@RequestMapping(value = "/api/v1", produces = MediaType.APPLICATION_JSON_UTF8_VALUE)
public class UploadController {

    private static final Logger logger = LoggerFactory.getLogger(UploadController.class);
    /**
     * 桶名，取配置
     */
    @Value("${jss.bucket}")
    private String bucket;

    private static String key = "file";
    private static String springProperties = "application.properties";

    @ResponseBody
    @RequestMapping(value = "/upload/{fileType}", method = RequestMethod.POST, produces = "application/json;charset=UTF-8")
    @ApiOperation(value = "文件上传", notes = "文件上传，form-data,key=file;fileType:pic、file", response = String.class, tags = {"UploadController",})
    public String uploadFile(HttpServletRequest request, @PathVariable(value = "fileType") String fileType) {
        String result = "";
        String fileAbsolutePath = "";
        try {
            logger.info("uploadFile begin! fileType={}", fileType);
            //写本地文档
            MultipartHttpServletRequest multipartHttpServletRequest = (MultipartHttpServletRequest) request;
            MultipartFile multipartFile = multipartHttpServletRequest.getFile(key);
            String fileName = multipartFile.getOriginalFilename();
            //文件名称加随机数处理，避免重名
            fileName = fileName.substring(0, fileName.lastIndexOf(".")) + "_" + System.currentTimeMillis() % 1000 + fileName.substring(fileName.lastIndexOf("."));
            fileAbsolutePath = getUploadPath() + fileName;
            writeFile(fileAbsolutePath, multipartFile.getBytes());
            //上传各种云的utils，返回一个上传后可供下载的url，注解掉，按需处理。传入本地文件的绝对路径以及云上桶名
            String url = AmazonS3Utils.uploadFileToS3(fileAbsolutePath, bucket);
            if (StringUtils.isNotBlank(url)) {
                //持久化file数据到数据库，返回数据ID，前台页面根据ID进行挂载，按需处理
                Long fileId = fileService.insertFile(url, fileType);
                result = fileId + "";
            } else {
                logger.error("上传云失败，文件本地路径={}", fileAbsolutePath);
                result = "上传云失败";
            }
        } catch (Exception e) {
            result = "上传异常";
            logger.error("uploadFile exception!", e);
        } finally {
            //上传完成之后，确保删除本地文件
            try {
                if (StringUtils.isNotBlank(fileAbsolutePath)) {
                    File f = new File(fileAbsolutePath);
                    if (f.exists()) {
                        f.delete();
                    }
                }
            } catch (Exception e) {
                logger.error("delete file exception", e);
                result = "删除本地文件异常";
            }
            logger.info("uploadFile end! result={}", result);
            return result;
        }
    }

    //通过spring的配置文件，来获取war包的绝对路径，并将文件上传到预先准备的文件夹下
    private String getUploadPath() {
        URL url = this.getClass().getClassLoader().getResource(springProperties);
        String uploadPath = url.getPath().replace(springProperties, "upload/");
        return uploadPath;
    }

    public static void writeFile(String fileAbsolutePath, byte[] content) throws IOException {
        FileOutputStream fos = new FileOutputStream(fileAbsolutePath);
        fos.write(content);
        fos.close();
    }

}

相应的，postMan中，调用的示例截图如下