在SpringBoot中通过RestTemplate提交文件到Github（白嫖图床）

Github仓库 + jsDelivr = 全球加速的免费图床

之前写过一篇帖子，GitHub + jsDelivr CDN 全球加速的免费图床，它不香吗？ 这篇帖子中，使用的是桌面客户端 PicGo，进行图片上传的。在这里我们使用SpringBoot中的RestTemplate作为客户端，上传文件到Github仓库。

先在Github中创建一个public的仓库，和AccessToken

参考上面的帖子，这里不再重复讲诉。

SpringBoot的yml文件中添加配置

github:
  bucket:
    # 配置仓库所属的用户名（如果是自己创建的，就是自己的用户名）
    user: "springboot-community"
    # 配置仓库名称
    repository: "twitter-bucket"
    # 配置自己的acccessToken
    access-token: "996e748cb47117adbf3**********"
    url: "https://cdn.jsdelivr.net/gh/${github.bucket.user}/${github.bucket.repository}/"
    api: "https://api.github.com/repos/${github.bucket.user}/${github.bucket.repository}/contents/"

你只需要配置好，上面自己有注释的3个配置就OK了

GithubUploaderGithubUploader

封装的一个工具类，根据上面的配置进行文件的上传

• 使用UUID重新命名文件，防止冲突
• 根据日期打散目录：yyyy/mm/dd

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Component;
import org.springframework.web.client.RestTemplate;
import org.springframework.web.multipart.MultipartFile;

import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import com.google.gson.JsonPrimitive;



@Component
public class GithubUploader {
	
	private static final Logger LOGGER = LoggerFactory.getLogger(GithubUploader.class);
	
	public static final String URI_SEPARATOR = "/";
	
	public static final Set<String> ALLOW_FILE_SUFFIX = new HashSet<> (Arrays.asList("jpg", "png", "jpeg", "gif")); 
	
	@Value("${github.bucket.url}")
	private String url;
	
	@Value("${github.bucket.api}")
	private String api;
	
	@Value("${github.bucket.access-token}")
	private String accessToken;
	
	@Autowired
	RestTemplate restTemplate;
	
	/**
	 * 上传文件到Github
	 * @param multipartFile
	 * @return 文件的访问地址
	 * @throws IOException
	 */
	public String upload (MultipartFile multipartFile) throws IOException {
		
		String suffix = this.getSuffix(multipartFile.getOriginalFilename()).toLowerCase();
		if (!ALLOW_FILE_SUFFIX.contains(suffix)) {
			throw new IllegalArgumentException("不支持的文件后缀：" + suffix);
		}
		
		// 重命名文件
		String fileName = UUID.randomUUID().toString().replace("-", "") + "." + suffix;
		
		// 目录按照日期打散
		String[] folders = this.getDateFolder();
		
		// 最终的文件路径
		String filePath = new StringBuilder(String.join(URI_SEPARATOR, folders)).append(fileName).toString();
		
		LOGGER.info("上传文件到Github：{}", filePath);
		
		JsonObject payload = new JsonObject();
		payload.add("message", new JsonPrimitive("file upload"));
		payload.add("content", new JsonPrimitive(Base64.getEncoder().encodeToString(multipartFile.getBytes())));
		
		HttpHeaders httpHeaders = new HttpHeaders();
		httpHeaders.set(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON_VALUE);
		httpHeaders.set(HttpHeaders.ACCEPT, MediaType.APPLICATION_JSON_VALUE);
		httpHeaders.set(HttpHeaders.AUTHORIZATION, "token " + this.accessToken);

		ResponseEntity<String> responseEntity = this.restTemplate.exchange(this.api + filePath, HttpMethod.PUT, 
				new HttpEntity<String>(payload.toString(), httpHeaders), String.class);
		
		if (responseEntity.getStatusCode().isError()) {
			// TODO 上传失败
		}
		
		JsonObject response = JsonParser.parseString(responseEntity.getBody()).getAsJsonObject();
		
		LOGGER.info("上传完毕: {}", response.toString());
		
		
		// TODO 序列化到磁盘备份
		
		return this.url + filePath;
	}
	
	/**
	 * 获取文件的后缀
	 * @param fileName
	 * @return
	 */
	protected String getSuffix(String fileName) {
		int index = fileName.lastIndexOf(".");
		if (index != -1) {
			String suffix = fileName.substring(index + 1);
			if (!suffix.isEmpty()) {
				return suffix;
			}
		}
		throw new IllegalArgumentException("非法的文件名称：" + fileName);
	}

	/**
	 * 按照年月日获取打散的打散目录
	 * yyyy/mmd/dd
	 * @return
	 */
	protected String[] getDateFolder() {
		String[] retVal = new String[3];

		LocalDate localDate = LocalDate.now();
		retVal[0] = localDate.getYear() + "";

		int month = localDate.getMonthValue();
		retVal[1] = month < 10 ? "0" + month : month + "";

		int day = localDate.getDayOfMonth();
		retVal[2] = day < 10 ? "0" + day : day + "";

		return retVal;
	}
}

Controller

import java.io.IOException;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import io.springboot.twitter.common.Message;
import io.springboot.twitter.github.GithubUploader;

@RestController
@RequestMapping("/upload")
public class UploadController {
	
	@Autowired
	private GithubUploader githubUploader;
	
	@PostMapping
	public Object upload (@RequestParam("file") MultipartFile multipartFile) throws IOException {
		return Message.success(this.githubUploader.upload(multipartFile));
	}
}

测试OK

通过CDN访问上传后的文件 😍
https://cdn.jsdelivr.net/gh/springboot-community/twitter-bucket/2020/06/169e652259a03b42f382433fb4481263d4.gif