FastDFS的配置、部署与API使用解读（3）以流的方式上传文件的客户端代码（转）

调用的API为：

String[] upload_file(

String group_name,//组名，不指定则可设为null

long file_size,//文件大小，必须制定

UploadCallback callback,//回调

String file_ext_name,

NameValuePair[] meta_list

)

    /** 
     * Upload File to DFS, directly transferring java.io.InputStream to java.io.OutStream 
     * @author Poechant 
     * @email zhongchao.ustc@gmail.com 
     * @param fileBuff, file to be uploaded. 
     * @param uploadFileName, the name of the file. 
     * @param fileLength, the length of the file. 
     * @return the file ID in DFS. 
     * @throws IOException  
     */  
    public String[] uploadFileByStream(InputStream inStream, String uploadFileName, long fileLength) throws IOException {  
          
        String[] results = null;  
        String fileExtName = "";  
        if (uploadFileName.contains(".")) {  
            fileExtName = uploadFileName.substring(uploadFileName.lastIndexOf(".") + 1);  
        } else {  
            logger.warn("Fail to upload file, because the format of filename is illegal.");  
            return results;  
        }  
          
        TrackerClient tracker = new TrackerClient();  
           TrackerServer trackerServer = tracker.getConnection();  
           StorageServer storageServer = null;  
           StorageClient1 client = new StorageClient1(trackerServer, storageServer);  
             
           NameValuePair[] metaList = new NameValuePair[3];  
           metaList[0] = new NameValuePair("fileName", uploadFileName);  
           metaList[1] = new NameValuePair("fileExtName", fileExtName);  
           metaList[2] = new NameValuePair("fileLength", String.valueOf(fileLength));  
             
           try {  
            // results[0]: groupName, results[1]: remoteFilename.  
            results = client.upload_file(null, fileLength, new UploadFileSender(inStream), fileExtName, metaList);  
        } catch (Exception e) {  
            logger.warn("Upload file \"" + uploadFileName + "\"fails");  
        }  
             
            trackerServer.close();  
          
        return results;       
    }  

其中的UploadFileSender是一个实现了UploadCallback接口的类：

    private static class UploadFileSender implements UploadCallback {  
          
        private InputStream inStream;  
          
        public UploadFileSender(InputStream inStream) {  
            this.inStream = inStream;  
        }  
          
        public int send(OutputStream out) throws IOException {  
            int readBytes;  
            while((readBytes = inStream.read()) > 0) {  
                out.write(readBytes);  
            }  
            return 0;  
        }  
    }