Method of a FileOutputStream instance will be open for A channel obtained via the getChannel method of a FileInputStream instance will be open for reading. Instance that is "open for reading," "open for writing," or "open for Seen by the originating object, and vice versa.Īt various points this class specifies that an Changing the file's content by writing bytes will change the content
![lock a file helpndoc lock a file helpndoc](https://designscad.com/wp-content/uploads/2017/01/expansion_joints_illustrated_dwg_section_for_autocad_84945-1000x497.gif)
Changing the file's length via theįile channel will change the length seen via the originating object, and vice Changing the channel's position, whetherĮxplicitly or by reading or writing bytes, will change the file position of Where the file channel is obtainedįrom an existing stream or random access file then the state of the fileĬhannel is intimately connected to that of the object whose getChannel Is connected to the same underlying file. That object's getChannel method, which returns a file channel that A file channel can also be obtained from anĮxisting FileInputStream, FileOutputStream, or RandomAccessFile object by invoking The exact nature of any such inconsistencies are system-dependentĪ file channel is created by invoking one of the open
![lock a file helpndoc lock a file helpndoc](https://chekape.files.wordpress.com/2016/05/09838-1.png)
Written, and whether they are running on the same machine or on some other Is true regardless of the language in which these other programs are Operating system and delays induced by network-filesystem protocols. The view provided by an instance of thisĬlass may or may not, however, be consistent with the views seen by otherĬoncurrently-running programs due to caching performed by the underlying To be consistent with other views of the same file provided by other The view of a file provided by an instance of this class is guaranteed Implementation and is therefore unspecified. Operations, in particular those that take an explicit position, may proceedĬoncurrently whether they in fact do so is dependent upon the underlying Still in progress will block until the first operation completes. Given time attempts to initiate a second such operation while the first is Only one operation that involves theĬhannel's position or can change its file's size may be in progress at any TheĬlose method may be invoked at any time, as specifiedīy the Channel interface. Into a very fast transfer directly to or from the filesystem cache.įile channels are safe for use by multiple concurrent threads. Versa, in a way that can be optimized by many operating systems Out to the underlying storage device, ensuring that data are not Than invoking the usual read or write methods. Position in a file in a way that does not affect the channel's currentĭirectly into memory for large files this is often much more efficient In addition to the familiar read, write, and close operations of byteĬhannels, this class defines the following file-specific operations:
![lock a file helpndoc lock a file helpndoc](http://image.135editor.com/uploadpdf/944390/201806/21636527-28.jpg)
Permissions, content type, and last-modification time this class does not When bytes are written beyond its current size the size of the fileįile may also have some associated metadata such as access Of bytes that can be read and written and whose current size can be queried. The file itself contains a variable-length sequence It has a current position within its file which canīe both queried and modified. A channel for reading, writing, mapping, and manipulating a file.Ī file channel is a SeekableByteChannel that is connected toĪ file.