com.liulishuo.filedownloader.stream

Class FileDownloadRandomAccessFile

java.lang.Object

com.liulishuo.filedownloader.stream.FileDownloadRandomAccessFile

All Implemented Interfaces:

FileDownloadOutputStream

public class FileDownloadRandomAccessFile
extends Object
implements FileDownloadOutputStream

The FileDownloadOutputStream implemented using RandomAccessFile.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	FileDownloadRandomAccessFile.Creator

Method Summary

Modifier and Type	Method and Description
void	close() Closes this output stream and releases any system resources associated with this stream.
void	flushAndSync() Flush all buffer to system and force all system buffers to synchronize with the underlying device.
void	seek(long offset) Sets the file-pointer offset, measured from the beginning of this file, at which the next read or write occurs.
void	setLength(long totalBytes) Sets the length of this file.
void	write(byte[] b, int off, int len) Writes len bytes from the specified byte array starting at offset off to this file.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

write

public void write(byte[] b,
                  int off,
                  int len)
           throws IOException

Description copied from interface: FileDownloadOutputStream

Writes len bytes from the specified byte array starting at offset off to this file.

Specified by:

write in interface FileDownloadOutputStream

Parameters:

b - the data.

off - the start offset in the data.

len - the number of bytes to write.

Throws:

IOException - if an I/O error occurs.

flushAndSync

public void flushAndSync()
                  throws IOException

Description copied from interface: FileDownloadOutputStream

Flush all buffer to system and force all system buffers to synchronize with the underlying device.

This method must ensure all data whatever on buffers of VM or buffers of system for this output stream must persist on the physical media, otherwise the breakpoint will not be integrity.

Specified by:

flushAndSync in interface FileDownloadOutputStream

Throws:

SyncFailedException - Thrown when the buffers cannot be flushed, or because the system cannot guarantee that all the buffers have been synchronized with physical media.

IOException

See Also:

OutputStream.flush(), FileDescriptor.sync()

close

public void close()
           throws IOException

Description copied from interface: FileDownloadOutputStream

Closes this output stream and releases any system resources associated with this stream. The general contract of close is that it closes the output stream. A closed stream cannot perform output operations and cannot be reopened.

The close method of OutputStream does nothing.

Specified by:

close in interface FileDownloadOutputStream

Throws:

IOException - if an I/O error occurs.

seek

public void seek(long offset)
          throws IOException

Description copied from interface: FileDownloadOutputStream

Sets the file-pointer offset, measured from the beginning of this file, at which the next read or write occurs. The offset may be set beyond the end of the file. Setting the offset beyond the end of the file does not change the file length. The file length will change only by writing after the offset has been set beyond the end of the file.

Specified by:

seek in interface FileDownloadOutputStream

Parameters:

offset - the offset position, measured in bytes from the beginning of the file, at which to set the file pointer.

Throws:

IOException - if offset is less than 0 or if an I/O error occurs.

See Also:

RandomAccessFile.seek(long), FileChannel.position(long)

setLength

public void setLength(long totalBytes)
               throws IOException

Description copied from interface: FileDownloadOutputStream

Sets the length of this file.

If the present length of the file as returned by the length method is greater than the newLength argument then the file will be truncated. In this case, if the file offset as returned by the getFilePointer method is greater than newLength then after this method returns the offset will be equal to newLength.

If the present length of the file as returned by the length method is smaller than the newLength argument then the file will be extended. In this case, the contents of the extended portion of the file are not defined.

Specified by:

setLength in interface FileDownloadOutputStream

Parameters:

totalBytes - The desired length of the file

Throws:

IOException - If an I/O error occurs

See Also:

RandomAccessFile.setLength(long)