Object Storage (COS)

Prerequisite: Tencent Object Storage Server (COS) has been set to public read and private write.

Idea: upload the picture on the front end, rename it and upload it to the Tencent Object Storage Server, and store the path and name in the database. When the picture needs to be accessed, the front end calls the interface, and the back end returns the address, and directly accesses the picture in the Object Storage Server through this address , when deleting, the front end passes in the picture id and name, and deletes the information in the database and the picture in the server respectively.

1. Import dependencies

<dependency>
    <groupId>com.qcloud</groupId>
    <artifactId>cos_api</artifactId>
    <version>5.6.8</version>
</dependency>

2. Tools

package com.example.demomybatis.entity;

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.region.Region;
import org.springframework.web.multipart.MultipartFile;

import java.io.File;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Random;

public class TencentCOSUploadFileUtil {
    // 存储桶名称
    private static final String BUCKET_NAME = "xxxx-xxxxxxxxxx";
    //secretId 秘钥id
    private static final String SECRET_ID = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
    //SecretKey 秘钥
    private static final String SECRET_KEY = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
    // 自定义文件夹名称，COS会根据这个路径自动创建对应文件夹
    private static final String PREFIX = "diary/";
    // 访问域名
    public static final String URL = "https:/xxxx-xxxxxxxxxx.cos.ap-beijing.myqcloud.com";
    // 创建COS 凭证
    private static final COSCredentials credentials = new BasicCOSCredentials(SECRET_ID, SECRET_KEY);
    // 配置 COS 区域 就购买时选择的区域
    private static final ClientConfig clientConfig = new ClientConfig(new Region("ap-beijing"));

    public static String uploadfile(MultipartFile file) {
        // 创建 COS 客户端连接
        COSClient cosClient = new COSClient(credentials, clientConfig);
        String fileName = file.getOriginalFilename();
        String fileNamePrefix = new SimpleDateFormat("yyyyMMddHHmmss").format(new Date()); // 将上传时间作为文件前缀名
        try {
            String substring = fileName.substring(fileName.lastIndexOf("."));
            File localFile = File.createTempFile(String.valueOf(System.currentTimeMillis()), substring);
            file.transferTo(localFile);
            // 同一时间上传多个就重名了，所以增加随机数
            Random random = new Random();
            fileName = PREFIX + fileNamePrefix + "-" + random.nextInt(10000) + substring;
            PutObjectRequest objectRequest = new PutObjectRequest(BUCKET_NAME, fileName, localFile); // 将文件上传至 COS
            cosClient.putObject(objectRequest);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            cosClient.shutdown();
        }
        // 给前端返回图片访问地址（用于读操作）和文件名(用于删除文件）
        return URL + "/" + fileName + ";" + fileName;
    }

    public static Boolean deletefile(String name) {
        try {
            COSClient cosClient = new COSClient(credentials, clientConfig);
            // 指定要删除的 bucket 和路径
            cosClient.deleteObject(BUCKET_NAME, name);
            // 关闭客户端(关闭后台线程)
            cosClient.shutdown();
        }catch (Exception e) {
            e.printStackTrace();
        }
        return true;
    }
}

3. controller layer

@PutMapping("add-picture")
    public void addPicture(@RequestParam MultipartFile file) throws IOException {
        String two = TencentCOSUploadFileUtil.uploadfile(file);
        String path = two.substring(0, two.indexOf(";"));
        String name = two.substring(two.indexOf(";") + 1);
        Picture picture = new Picture(null, path, name); // null处为id
        calendarService.addPicture(picture);
    }