1.登录七牛云官网，注册账号并登录

2.在项目中导入七牛云依赖

<!-- 七牛云依赖 -->
<!-- https://mvnrepository.com/artifact/com.qiniu/qiniu-java-sdk -->
<dependency>
    <groupId>com.qiniu</groupId>
    <artifactId>qiniu-java-sdk</artifactId>
    <version>7.9.3</version>
</dependency>

3.编写创建文件名工具类

package com.handsome.utils;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;

/**
 * @Author 识时务者
 * @Date 2022/03/22 19:00
 * @Version 1.0
 */
@SuppressWarnings({"all"})
public class CreateDestFileNameUtil {
    private volatile static CreateDestFileNameUtil createDestFileUtil;

    private CreateDestFileNameUtil() {
    }

    public static CreateDestFileNameUtil getCreateDestFileUtil() {
        if (createDestFileUtil == null) {
            synchronized (CreateDestFileNameUtil.class) {
                if (createDestFileUtil == null) {
                    createDestFileUtil = new CreateDestFileNameUtil();
                }
            }
        }
        return createDestFileUtil;
    }

    // 上传的七牛云的获取文件名称的方法
    public Map<String, Object> getDestFile(String fileName) {
        String suffixName = fileName.substring(fileName.lastIndexOf("."));
        // 生成文件名称通用方法
        SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd_HHmmss");
        Random r = new Random();
        StringBuilder tempName = new StringBuilder();
        tempName.append(sdf.format(new Date())).append(r.nextInt(100)).append(suffixName);
        String newFileName = tempName.toString();
        Map<String, Object> map = new HashMap();
        map.put("newFileName", newFileName);
        return map;
    }
}

4.编写连接七牛云工具类

package com.handsome.utils;

import com.alibaba.fastjson.JSON;
import com.qiniu.common.QiniuException;
import com.qiniu.http.Response;
import com.qiniu.storage.Configuration;
import com.qiniu.storage.Region;
import com.qiniu.storage.UploadManager;
import com.qiniu.storage.model.DefaultPutRet;
import com.qiniu.util.Auth;
import org.springframework.stereotype.Component;

import java.io.InputStream;

/**
 * @Author Handsome
 * @Date 2022/4/24 9:39
 * @Version 1.0
 */
@SuppressWarnings({"all"})
@Component
public class QiniuUtils {

    // 设置需要操作的账号的AK和SK
    private static final String ACCESS_KEY = "你的七牛云ACCESS_KEY";
    private static final String SECRET_KEY = "你的七牛云SECRET_KEY";

    // 密钥
    private static final Auth auth = Auth.create(ACCESS_KEY, SECRET_KEY);

    // 要上传的空间名称
    private static final String BUCKETNAME = "你的七牛云创建的空间名称";

    // 认证信息 不能使用static的upToken 会过期
//    private static final String upToken = auth.uploadToken(BUCKETNAME);

    // 外链默认域名
    public static final String DOMAIN = "你的七牛云外链默认域名";
    例如：http://cdn.handsomehjj.vip/handsomeforum/

    public boolean upload(InputStream file, String fileName) {

        //构造一个带指定 Region 对象的配置类
        Configuration cfg = new Configuration(Region.huanan());  //根据自己的对象空间的地址选（华南）
        //...其他参数参考类注释
        UploadManager uploadManager = new UploadManager(cfg);
        //默认不指定key的情况下，以文件内容的hash值作为文件名
        try {
            String upToken = auth.uploadToken(BUCKETNAME);
            Response response = uploadManager.put(file, "handsomeforum/" + fileName, upToken, null, null);
            // 解析上传成功的结果
//                DefaultPutRet putRet = new Gson().fromJson(response.bodyString(), DefaultPutRet.class);
            DefaultPutRet putRet = JSON.parseObject(response.bodyString(), DefaultPutRet.class);

            // 这个returnPath是获得到的外链地址,通过这个地址可以直接打开图片
//            String returnPath = DOMAIN + putRet.key;

            return true;
        } catch (QiniuException ex) {
            Response r = ex.response;
            System.err.println(r.toString());
            try {
                System.err.println(r.bodyString());
            } catch (QiniuException ex2) {
                //ignore
            }
        }
        return false;
    }

5.编写前端请求的Controller

	// axios上传头像到七牛云
    @PostMapping("/user/upload/yourAvatar/{uid}")
    @ResponseBody
    public String uploadyourAvatar(@PathVariable String uid,
                                   HttpServletRequest httpServletRequest,
                                   @RequestParam(value = "file", required = true) MultipartFile file) throws Exception {
        String fileName = file.getOriginalFilename();
        if (fileName.isEmpty()) {
            Map datamap = new HashMap<>();
            datamap.put("code", 555);
            datamap.put("msg", "未上传图片！");
            String jasonmap = JSONObject.toJSONString(datamap);
            return jasonmap;
        }

        // 获取destFile和newFileName
        CreateDestFileNameUtil createDestFileUtil = CreateDestFileNameUtil.getCreateDestFileUtil();
        Map<String, Object> map = createDestFileUtil.getDestFile(fileName);
        String newFileName = (String) map.get("newFileName");

// 使用七牛云工具列上传图片
        boolean upload = qiniuUtils.upload(file.getInputStream(), newFileName);
        if (upload) {
            // 头像图片地址
            String yourAvatar = QiniuUtils.DOMAIN + newFileName;
            Map datamap = new HashMap<>();
            datamap.put("code", 200);
            datamap.put("msg", "头像上传成功！请重新登录！");
            String jasonmap = JSONObject.toJSONString(datamap);
            return jasonmap;
        } else {
            Map datamap = new HashMap<>();
            datamap.put("code", 555);
            datamap.put("msg", "图片上传失败！");
            String jasonmap = JSONObject.toJSONString(datamap);
            return jasonmap;
        }
    }