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

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;
}
}

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原文链接：
http://blog.csdn.net/poechant/article/details/6987427