FastDFS的java客户端支持随机读取吗？

happystar22

如题~~

doit_zzg

回复 1# happystar22


    能解释下你说的随机读取是指什么意思呢？
   
    FastDFS client  通过API 在向Tracker 请求Storage 的时候，Tracker 可以根据负载均衡策略（其中包含轮询等等几种策略），返回合适的storage。你说的随机读取是指的负载均衡策略？ 可以把tracker 上传、下载支持的策略贴出来：

# which storage server to upload file
# 0: round robin (default)
# 1: the first server order by ip address
# 2: the first server order by priority (the minimal)
store_server=0

# which path(means disk or mount point) of the storage server to upload file
# 0: round robin
# 2: load balance, select the max free space path to upload file
store_path=0

# which storage server to download file
# 0: round robin (default)
# 1: the source storage server which the current file uploaded to
download_server=0

happystar22

哦，不是，不好意思，没说清楚。我指的是支持文件的随机读取吗？就是从一个文件的某个字节开始读，不是从头开始。

doit_zzg

回复 3# happystar22


            /**
        * download file from storage server
        * @param file_id the file id(including group name and filename)
        * @param file_offset the start offset of the file
        * @param download_bytes download bytes, 0 for remain bytes from offset
        * @return file content/buff, return null if fail
        */
        public byte[] download_file1(String file_id, long file_offset, long download_bytes) throws IOException, Exception
        {
                String[] parts = new String[2];
                this.errno = this.split_file_id(file_id, parts);
                if (this.errno != 0)
                {
                        return null;
                }
               
                return this.download_file(parts[0], parts[1], file_offset, download_bytes);
        }


        注意上面的file_offset参数

happystar22

哦好，我再看看源代码吧，谢谢哈~~~