1，申请key和密钥

2，引入依赖

 <dependency><groupId>com.qcloud</groupId><artifactId>cos_api</artifactId><version>5.6.24</version></dependency>

3，工具类

package com.example.activity.utils;import cn.hutool.core.date.DateUtil;
import cn.hutool.json.JSONUtil;
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.GeneratePresignedUrlRequest;
import com.qcloud.cos.model.ObjectMetadata;
import com.qcloud.cos.model.PutObjectRequest;
import com.qcloud.cos.region.Region;import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;public class TencentCOSUtils {/*** COS SECRETID*/private static String SECRETID = "ebOzOp8NafZL2ZxKX";/*** COS SECRETKEY*/private static String SECRETKEY = "WBhz59DF";/*** COS BUCKETNAME bucket的命名规则为{name}-{appid} ，存储桶名称必须为此格式*/private static String BUCKETNAME = "i959430";private static String filePathPrefix = "/jo";private static String region = "ou";public static void main(String[] args) throws FileNotFoundException {File file = new File("G:\\Download\\aa.jpg");Map<String, String> upload = upload(file);System.out.println(JSONUtil.toJsonStr(upload));}/**** 上传文件* @param file* @return*/public static Map<String, String> upload(File file) {COSClient cosClient = null;FileInputStream fileInputStream = null;Map<String, String> result = new HashMap<>();try {fileInputStream = new FileInputStream(file);//获取最后一个.的位置int lastIndexOf = file.getName().lastIndexOf(".");//获取文件的后缀名 .jpgString suffix = file.getName().substring(lastIndexOf);String filename = filePathPrefix + "/" + DateUtil.format(new Date(), "yyyyMMdd") + "/" + System.currentTimeMillis() + suffix;// 1 初始化用户身份信息（secretId, secretKey）。COSCredentials cred = new BasicCOSCredentials(SECRETID, 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中包含了设置 region, https(默认 http), 超时, 代理等 set 方法, 使用可参见源码或者接口文档 FAQ中说明。ClientConfig clientConfig = new ClientConfig(new Region(region));// 3 生成 cos 客户端。cosClient = new COSClient(cred, clientConfig);// 指定要上传到的存储桶，指定要上传到 COS 上对象键ObjectMetadata objectMetadata = new ObjectMetadata();PutObjectRequest putObjectRequest = new PutObjectRequest(BUCKETNAME, filename, fileInputStream, objectMetadata);cosClient.putObject(putObjectRequest);result.put("fileName", filename);result.put("absolutePath", getAbsolutePath(filename));} catch (Exception e) {e.printStackTrace();} finally {if (cosClient != null) {// 关闭客户端(关闭后台线程)cosClient.shutdown();}if (fileInputStream != null) {try {fileInputStream.close();} catch (IOException e) {e.printStackTrace();}}}return result;}/*** 下载文件** @param fileName COS桶的文件路径* @param  outPath 输出路径*/public static void downFile(String fileName, String outPath) {COSCredentials cred = new BasicCOSCredentials(SECRETID, SECRETKEY);ClientConfig clientConfig = new ClientConfig(new Region(region));COSClient cosClient = new COSClient(cred, clientConfig);GetObjectRequest getObjectRequest = new GetObjectRequest(BUCKETNAME, fileName);ObjectMetadata object = cosClient.getObject(getObjectRequest, new File(outPath + "/" + fileName));System.out.println(object);}// 删除文件public static void delete(String filename) {COSClient cosClient = null;try {// 1 初始化用户身份信息（secretId, secretKey）。COSCredentials cred = new BasicCOSCredentials(SECRETID, 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中包含了设置 region, https(默认 http), 超时, 代理等 set 方法, 使用可参见源码或者接口文档 FAQ// 中说明。ClientConfig clientConfig = new ClientConfig(new Region(region));// 3 生成 cos 客户端。cosClient = new COSClient(cred, clientConfig);cosClient.deleteObject(BUCKETNAME, filename);} finally {if (cosClient != null) {// 关闭客户端(关闭后台线程)cosClient.shutdown();}}}/**** 获取文件的绝对路径* @param fileName 文件名称* @return url*/public static String getAbsolutePath(String fileName) {// 1 初始化用户身份信息(secretId, secretKey)COSCredentials cred = new BasicCOSCredentials(SECRETID, 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中包含了设置region, https(默认http), 超时, 代理等set方法, 使用可参见源码或者接口文档FAQ中说明ClientConfig clientConfig = new ClientConfig(new Region(region));// 3 生成cos客户端COSClient cosclient = new COSClient(cred, clientConfig);// 设置URL过期时间为1小时 60*60*1000()Date expiration = new Date(System.currentTimeMillis() + 60 * 60 * 1000);GeneratePresignedUrlRequest generatePresignedUrlRequest = new GeneratePresignedUrlRequest(BUCKETNAME, fileName);// 设置签名过期时间(可选), 若未进行设置, 则默认使用 ClientConfig 中的签名过期时间(5分钟)generatePresignedUrlRequest.setExpiration(expiration);String url = cosclient.generatePresignedUrl(generatePresignedUrlRequest).toString();return url;}}

4，注意事项

1，SECRETID和SECRETKEY 需要有读写权限
2，获取的文件地址有时间限制，过期后需要重新获取