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Class Summary Class Description FtpDataAsyncConn Main class that handles Data connection using asynchronous connection with NettyFtpTransfer Class that owns one transfer to be runFtpTransferControl Main class that handles transfers and their execution
Package org.waarp.ftp.core.data Description
Classes implementing Data and Transfer status
When a transfer should occur, here are the steps:
When a transfer should occur, here are the steps:
- The connection is prepared through a PORT or PASV command. The PASV command implies the creation of a new binded address (connection from the client to the server for PASSIVE mode) (or to reuse an already opened binded address). Then it stores the session that will be used by this new data session.
- The transfer command is received and is followed by several steps:
- First it prepares the FtpFile object
- It opens the data connection . Two possibilities:
- The transfer is initiated by calling setNewFtpTransfer method of the FtpTransferControl object. This starts a new thread (FtpTransferExecutor) to execute the transfer.
The PORT command implies the preparation of the future data connection from the server to the client (ACTIVE mode). In this mode, the session does not need to be setup before since it will be setup before the real connection process.
In both commands, if a previously data connection is already opened, it is closed before any new startup.
1) PASSIVE mode where the server waits for the client to initiate the real connection.
2) ACTIVE mode where the server will initiate the data connection.
The DataNetworkHandler will inform back the FtpTransferControl that the connection is ready. Then the FtpDataAsyncConn is also informed of this status.
For STORE like operations, it waits for the end of the transfer from the data network handler (when the last block is received or the data connection is over).
For LIST like commands, it immediately sends the result as wanted.
For RETRIEVE like commands, it starts the sending of the file (trueRetrieve method of the FtpFile object).
For STORE and RETRIEVE cases, it is waiting for the FtpTransferControl to inform back that everything is really over (waitForCommand). For each cases, when it is over, it informs back the FtpTransferControl the transfer is finished (setEndOfTransfer method). This enables to send early end message (success or error) and also final message (again success or error) after a check is completed.