文章首发于：clawhub.club

简介

分布式文件系统FastDFS非常适合中小型项目，比如说作为图片服务器。
happyfish100大神的github:fastdfs,fastdfs-client-java。

简单的对客户端进行了连接池的封装，方便使用。

  • 系统启动，池子管理连接
  • 心跳确认连接是否可靠
  • 构造器模式创建连接池
  • 回调方式使用客户端

核心代码

初始化连接池

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
/**
     * Build fast dfs conn pool.
     *
     * @return the fast dfs conn pool
     */
    public FastDFSConnPool build() {
        // 初始化空闲连接池
        idleConnectionPool = new LinkedBlockingQueue<>(maxPoolSize);
        //初始化全局参数
        try {
            ClientGlobal.init(confFileName);
        } catch (IOException | MyException e) {
            throw new RuntimeException("init client global exception.", e);
        }
        // 往线程池中添加默认大小的线程
        TrackerServer trackerServer;
        for (int i = 0; i < minPoolSize; i++) {
            //获取到连接
            trackerServer = createTrackerServer();
            if (trackerServer != null) {
                //放入空闲池
                idleConnectionPool.offer(trackerServer);
            }
        }
        // 注册心跳
        new HeartBeat(this).beat();

        return this;
    }

客户端执行请求

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
/**
     * 执行方式
     *
     * @param <T>    the type parameter
     * @param invoke the invoke
     * @return the t
     */
    public <T> T processFdfs(CallBack<T> invoke) {
        TrackerServer trackerServer = null;
        T t;
        try {
            //获取tracker连接
            trackerServer = fastDFSConnPool.checkOut();
            //获取storage
            StorageClient1 storageClient = new StorageClient1(trackerServer, null);
            //执行操作
            t = invoke.invoke(storageClient);
            //释放连接
            fastDFSConnPool.checkIn(trackerServer);
            return t;
        } catch (Exception e) {
            //删除链接
            fastDFSConnPool.drop(trackerServer);
            throw new RuntimeException(e);
        }
    }

心跳

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
/**
 * 心跳任务
 */
private class HeartBeatTask implements Runnable {

    @Override
    public void run() {
        LinkedBlockingQueue<TrackerServer> idleConnectionPool = fastDFSConnPool.getIdleConnectionPool();
        TrackerServer ts = null;
        for (int i = 0; i < idleConnectionPool.size(); i++) {
            try {
                ts = idleConnectionPool.poll(fastDFSConnPool.getWaitTimes(), TimeUnit.SECONDS);
                if (ts != null) {
                    ProtoCommon.activeTest(ts.getSocket());
                    idleConnectionPool.add(ts);
                } else {
                    //代表已经没有空闲长连接
                    break;
                }
            } catch (Exception e) {
                //发生异常,要删除，进行重建
                logger.error("heart beat conn  have dead, and reconnect.", e);
                fastDFSConnPool.drop(ts);
            }
        }

    }
}

使用方式

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
//初始化连接池
       FastDFSConnPool fastDFSConnPool = new FastDFSConnPool()
               .confFileName("./config/fdfs_client.conf")
               .maxPoolSize(8)
               .minPoolSize(1)
               .reConnNum(2)
               .waitTimes(2).build();

       //使用客户端
       FastDFSClient client = new FastDFSClient(fastDFSConnPool);
       //上传  ileName 文件全路径 extName 文件扩展名，不包含（.） metas 文件扩展信息
       String parts = client.processFdfs(storageClient -> storageClient.upload_file1("fileName", "extName", new NameValuePair[0]));
       //下载 fileId: group1/M00/00/00/wKgRsVjtwpSAXGwkAAAweEAzRjw471.jpg
       byte[] bytes = client.processFdfs(storageClient -> storageClient.download_file1("fileId"));
       //删除 -1失败,0成功
       int result = client.processFdfs(storageClient -> storageClient.delete_file1("fileId"));
       //获取远程服务器文件资源信息  groupName   文件组名 如：group1  remoteFileName M00/00/00/wKgRsVjtwpSAXGwkAAAweEAzRjw471.jpg
       FileInfo fileInfo = client.processFdfs(storageClient -> storageClient.get_file_info("groupName", "remoteFileName"));

github地址

FastDFS-Pool