上篇文章介绍了如何使用Spring Boot上传文件，这篇文章我们介绍如何使用Spring Boot将文件上传到分布式文件系统FastDFS中。
这个项目会在上一个项目的基础上进行构建。
1、pom包配置
我们使用Spring Boot最新版本1.5.9、jdk使用1.8、tomcat8.0。
<dependency>
<groupId>org.csource</groupId>
<artifactId>fastdfs-client-java</artifactId>
<version>1.27-SNAPSHOT</version>
</dependency>
加入了fastdfs-client-java包，用来调用FastDFS相关的API。
2、配置文件
resources目录下添加fdfs_client.conf文件
connect_timeout = 60
network_timeout = 60
charset = UTF-8
http.tracker_http_port = 8080
http.anti_steal_token = no
http.secret_key = 123456
tracker_server = 192.168.53.85:22122
tracker_server = 192.168.53.86:22122
配置文件设置了连接的超时时间，编码格式以及tracker_server地址等信息
详细内容参考：fastdfs-client-java
3、封装FastDFS上传工具类
封装FastDFSFile，文件基础信息包括文件名、内容、文件类型、作者等。
public class FastDFSFile {
private String name;
private byte[] content;
private String ext;
private String md5;
private String author;
//省略getter、setter
封装FastDFSClient类，包含常用的上传、下载、删除等方法。
首先在类加载的时候读取相应的配置信息，并进行初始化。
static {
try {
String filePath = new ClassPathResource("fdfs_client.conf").getFile().getAbsolutePath();;
ClientGlobal.init(filePath);
trackerClient = new TrackerClient();
trackerServer = trackerClient.getConnection();
storageServer = trackerClient.getStoreStorage(trackerServer);
} catch (Exception e) {
logger.error("FastDFS Client Init Fail!",e);
}
}
文件上传
public static String[] upload(FastDFSFile file) {
logger.info("File Name: " + file.getName() + "File Length:" + file.getContent().length);
NameValuePair[] meta_list = new NameValuePair[1];
meta_list[0] = new NameValuePair("author", file.getAuthor());
long startTime = System.currentTimeMillis();
String[] uploadResults = null;
try {
storageClient = new StorageClient(trackerServer, storageServer);
uploadResults = storageClient.upload_file(file.getContent(), file.getExt(), meta_list);
} catch (IOException e) {
logger.error("IO Exception when uploadind the file:" + file.getName(), e);
} catch (Exception e) {
logger.error("Non IO Exception when uploadind the file:" + file.getName(), e);
}
logger.info("upload_file time used:" + (System.currentTimeMillis() - startTime) + " ms");
if (uploadResults == null) {
logger.error("upload file fail, error code:" + storageClient.getErrorCode());
}
String groupName = uploadResults[0];
String remoteFileName = uploadResults[1];
logger.info("upload file successfully!!!" + "group_name:" + groupName + ", remoteFileName:" + " " + remoteFileName);
return uploadResults;
}
使用FastDFS提供的客户端storageClient来进行文件上传，最后将上传结果返回。
根据groupName和文件名获取文件信息。
public static FileInfo getFile(String groupName, String remoteFileName) {
try {
storageClient = new StorageClient(trackerServer, storageServer);
return storageClient.get_file_info(groupName, remoteFileName);
} catch (IOException e) {
logger.error("IO Exception: Get File from Fast DFS failed", e);
} catch (Exception e) {
logger.error("Non IO Exception: Get File from Fast DFS failed", e);
}
return null;
}
下载文件
public static InputStream downFile(String groupName, String remoteFileName) {
try {
storageClient = new StorageClient(trackerServer, storageServer);
byte[] fileByte = storageClient.download_file(groupName, remoteFileName);
InputStream ins = new ByteArrayInputStream(fileByte);
return ins;
} catch (IOException e) {
logger.error("IO Exception: Get File from Fast DFS failed", e);
} catch (Exception e) {
logger.error("Non IO Exception: Get File from Fast DFS failed", e);
}
return null;
}
删除文件
public static void deleteFile(String groupName, String remoteFileName)
throws Exception {
storageClient = new StorageClient(trackerServer, storageServer);
int i = storageClient.delete_file(groupName, remoteFileName);
logger.info("delete file successfully!!!" + i);
}
使用FastDFS时，直接调用FastDFSClient对应的方法即可。
4、编写上传控制类
从MultipartFile中读取文件信息，然后使用FastDFSClient将文件上传到FastDFS集群中。
public String saveFile(MultipartFile multipartFile) throws IOException {
String[] fileAbsolutePath={};
String fileName=multipartFile.getOriginalFilename();
String ext = fileName.substring(fileName.lastIndexOf(".") + 1);
byte[] file_buff = null;
InputStream inputStream=multipartFile.getInputStream();
if(inputStream!=null){
int len1 = inputStream.available();
file_buff = new byte[len1];
inputStream.read(file_buff);
}
inputStream.close();
FastDFSFile file = new FastDFSFile(fileName, file_buff, ext);
try {
fileAbsolutePath = FastDFSClient.upload(file); //upload to fastdfs
} catch (Exception e) {
logger.error("upload file Exception!",e);
}
if (fileAbsolutePath==null) {
logger.error("upload file failed,please upload again!");
}
String path=FastDFSClient.getTrackerUrl()+fileAbsolutePath[0]+ "/"+fileAbsolutePath[1];
return path;
}
请求控制，调用上面方法saveFile()。
@PostMapping("/upload") //new annotation since 4.3
public String singleFileUpload(@RequestParam("file") MultipartFile file,
RedirectAttributes redirectAttributes) {
if (file.isEmpty()) {
redirectAttributes.addFlashAttribute("message", "Please select a file to upload");
return "redirect:uploadStatus";
}
try {
// Get the file and save it somewhere
String path=saveFile(file);
redirectAttributes.addFlashAttribute("message",
"You successfully uploaded '" + file.getOriginalFilename() + "'");
redirectAttributes.addFlashAttribute("path",
"file path url '" + path + "'");
} catch (Exception e) {
logger.error("upload file failed",e);
}
return "redirect:/uploadStatus";
}
上传成功之后，将文件的路径展示到页面，效果图如下：
在浏览器中访问此Url，可以看到成功通过FastDFS展示：
这样使用Spring Boot 集成FastDFS的案例就完成了。
