Spring boot 上传文件到腾讯云对象储存COS（完整步骤流程）

1.登录到腾讯云平台（https://cloud.tencent.com）

2.选择【云产品，对象存储】

3.新建

4.查看刚刚创建存

5.选择

6.创建Spring boot项目

<!--腾讯云存储依赖-->
<dependency>
    <groupId>com.qcloud</groupId>
    <artifactId>cos_api</artifactId>
    <version>5.2.4</version>
</dependency>

7.把刚刚我们创建的腾讯云存储桶的信息添加进Spring boot项目的配置文件中

8.编写上传的控制器

package com.pingao.guns.modular.demo.controller;

import com.qcloud.cos.COSClient;
import com.qcloud.cos.ClientConfig;
import com.qcloud.cos.auth.BasicCOSCredentials;
import com.qcloud.cos.auth.COSCredentials;
import com.qcloud.cos.model.PutObjectRequest;
import com.qcloud.cos.model.PutObjectResult;
import com.qcloud.cos.region.Region;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpSession;
import java.io.File;
import java.io.IOException;
import java.util.Calendar;
import java.util.UUID;

/**
 * 文件上传控制器
 */
@Controlle
@RequestMapping(value = "/upload")
public class UploadController {
    
    @Value("${spring.tengxun.accessKey}")
    private String accessKey;
    @Value("${spring.tengxun.secretKey}")
    private String secretKey;
    @Value("${spring.tengxun.bucket}")
    private String bucket;
    @Value("${spring.tengxun.bucketName}")
    private String bucketName;
    @Value("${spring.tengxun.path}")
    private String path;
    @Value("${spring.tengxun.qianzui}")
    private String qianzui;
    /**
     * 上传道腾讯云服务器（https://cloud.tencent.com/document/product/436/10199）
     * @return
     */
    @RequestMapping(value = "/tengxun",method = RequestMethod.POST)
    @ResponseBody
    public Object Upload(@RequestParam(value = "file") MultipartFile file, HttpSession session){
        if(file == null){
            return new UploadMsg(0,"文件为空",null);
        }
        String oldFileName = file.getOriginalFilename();
        String eName = oldFileName.substring(oldFileName.lastIndexOf("."));
        String newFileName = UUID.randomUUID()+eName;
        Calendar cal = Calendar.getInstance();
        int year = cal.get(Calendar.YEAR);
        int month=cal.get(Calendar.MONTH);
        int day=cal.get(Calendar.DATE);
        // 1 初始化用户身份信息(secretId, secretKey)
        COSCredentials cred = new BasicCOSCredentials(accessKey, secretKey);
        // 2 设置bucket的区域, COS地域的简称请参照 https://cloud.tencent.com/document/product/436/6224
        ClientConfig clientConfig = new ClientConfig(new Region(bucket));
        // 3 生成cos客户端
        COSClient cosclient = new COSClient(cred, clientConfig);
        // bucket的命名规则为{name}-{appid} ，此处填写的存储桶名称必须为此格式
        String bucketName = this.bucketName;

        // 简单文件上传, 最大支持 5 GB, 适用于小文件上传, 建议 20 M 以下的文件使用该接口
        // 大文件上传请参照 API 文档高级 API 上传
        File localFile = null;
        try {
            localFile = File.createTempFile("temp",null);
            file.transferTo(localFile);
            // 指定要上传到 COS 上的路径
            String key = "/"+this.qianzui+"/"+year+"/"+month+"/"+day+"/"+newFileName;
            PutObjectRequest putObjectRequest = new PutObjectRequest(bucketName, key, localFile);
            PutObjectResult putObjectResult = cosclient.putObject(putObjectRequest);
            return new UploadMsg(1,"上传成功",this.path + putObjectRequest.getKey());
        } catch (IOException e) {
            return new UploadMsg(-1,e.getMessage(),null);
        }finally {
            // 关闭客户端(关闭后台线程)
            cosclient.shutdown();
        }
    }
    
    private class UploadMsg{
        public int status;
        public String msg;
        public String path;

        public UploadMsg() {
            super();
        }

        public UploadMsg（ int status，String msg，String path）{        
        this.status = status;
        this.msg = msg;
        this.path = path;
      }
}