SpringBoot访问FastDFS

1. 引入jar依赖

   <parent>
     <groupId>org.springframework.boot</groupId>
     <artifactId>spring-boot-starter-parent</artifactId>
     <version>2.0.5.RELEASE</version>
   </parent>
   
   <dependencies>
     <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
     </dependency>
     <dependency>
    <groupId>com.github.tobato</groupId>
    <artifactId>fastdfs-client</artifactId>
    <version>1.26.1-RELEASE</version>
     </dependency>
   </dependencies>

2. 配置文件application.yml

   fdfs:
     connectTimeout: 600
     trackerList:
    - 192.168.211.130:22122
    - 192.168.211.135:22122
    - 192.168.211.136:22122
   server:
     port: 8899

3. 编写上传下载文件的服务类

   package com.fastdfs.service;
   
   import com.github.tobato.fastdfs.domain.StorePath;
   import com.github.tobato.fastdfs.proto.storage.DownloadByteArray;
   import com.github.tobato.fastdfs.service.FastFileStorageClient;
   import org.springframework.beans.factory.annotation.Autowired;
   import org.springframework.stereotype.Component;
   
   import java.io.ByteArrayInputStream;
   import java.io.IOException;
   
   @Component
   public class FastDFSClientService {
     @Autowired
     private FastFileStorageClient fastFileStorageClient;
     /*
   * 文件上传
   *
   * @param bytes 文件字节
   * @param fileSize 文件大小
   * @param extension 文件扩展名
   * @return fastDfs路径
   */
     public String uploadFile(byte[] bytes, long fileSize, String extension) {
    ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(bytes);
    StorePath storePath = fastFileStorageClient.uploadFile(byteArrayInputStream, fileSize, extension, null);
    System.out.println(storePath.getGroup() + ":" + storePath.getPath() + ":" + storePath.getFullPath());
    return storePath.getFullPath();
     }
   
     /*
   * 下载文件
   *
   * @param fileUrl 文件URL
   * @return 文件字节
   * @throws IOException
   */
     public byte[] downloadFile(String fileUrl) throws IOException {
    String group = fileUrl.substring(0, fileUrl.indexOf("/"));
    String path = fileUrl.substring(fileUrl.indexOf("/") + 1);
    DownloadByteArray downloadByteArray = new DownloadByteArray();
    byte[] bytes = fastFileStorageClient.downloadFile(group, path, downloadByteArray);
    return bytes;
     }
   
   }

4. 控制器类

   package com.fastdfs.controller;
   
   import com.fastdfs.service.FastDFSClientService;
   import org.springframework.beans.factory.annotation.Autowired;
   import org.springframework.web.bind.annotation.RequestMapping;
   import org.springframework.web.bind.annotation.RestController;
   import org.springframework.web.multipart.MultipartFile;
   
   import javax.servlet.ServletOutputStream;
   import javax.servlet.http.HttpServletResponse;
   import java.io.IOException;
   import java.net.URLEncoder;
   
   @RestController
   @RequestMapping("/fastdfs")
   public class FastDFSController {
     @Autowired
     private FastDFSClientService fastDFSClientService;
   
     @RequestMapping("/upload")
     public String uploadFile(MultipartFile file) throws IOException {
    byte[] bytes = file.getBytes();
    String originalFileName = file.getOriginalFilename();
    String extension = originalFileName.substring(originalFileName.lastIndexOf(".") + 1);
    String fileName = file.getName();
    long fileSize = file.getSize();
    System.out.println(originalFileName + ":" + fileName + ":" + fileSize + ":" + extension + ":" + bytes.length);
    return fastDFSClientService.uploadFile(bytes, fileSize, extension);
     }
   
     @RequestMapping("/download")
     public void downloadFile(String fileUrl, HttpServletResponse response) throws IOException {
    byte[] bytes = fastDFSClientService.downloadFile(fileUrl);
    response.setHeader("Content-disposition", "attachment;filename=" + URLEncoder.encode(fileUrl, "UTF-8"));
    response.setCharacterEncoding("UTF-8");
    ServletOutputStream outputStream = null;
    try {
      outputStream = response.getOutputStream();
      outputStream.write(bytes);
    } catch (IOException e) {
      e.printStackTrace();
    } finally {
      try {
        outputStream.flush();
        outputStream.close();
      } catch (IOException e) {
        e.printStackTrace();
      }
    }
     }
   
   }

5. 编写启动类

   package com.fastdfs;
   
   import com.github.tobato.fastdfs.FdfsClientConfig;
   import org.springframework.boot.SpringApplication;
   import org.springframework.boot.autoconfigure.SpringBootApplication;
   import org.springframework.context.annotation.EnableMBeanExport;
   import org.springframework.context.annotation.Import;
   import org.springframework.jmx.support.RegistrationPolicy;
   
   //解决jmx重复注册bean的问题
   @EnableMBeanExport(registration = RegistrationPolicy.IGNORE_EXISTING)
   //只需要一行注解就可以拥有带有连接池的FastDFS Java客户端了
   @Import(FdfsClientConfig.class)
   @SpringBootApplication
   public class FastDfsApplicationMain {
   
     public static void main(String[] args) {
    SpringApplication.run(FastDfsApplicationMain.class, args);
     }
   }

6. 使用postman 进行测试
   

   业务场景

   头像上传

   

   nginx头像缩略图

   处理思路:

7. 上传图片时，直接处理成缩略图，不是很灵活，业务很确定可以使用

8. 先存储图片，使用时，实时计算
   

   附件

   上传附件
   
   下载附件
   思考：是使用直接的url，还是需要写一个处理请求
   

   避免重复

   解决方案：
   上传成功后计算文件对应的MD5然后存入MySQL，添加文件时把文件MD5和之前存入MYSQL中的存储的信息对比。
   参考:DigestUtils.md5DigestAsHex(bytes)。