edtFTPj/Free - Open-source FTP library for Java | Download

com.enterprisedt.net.ftp
Class FTPInputStream

java.lang.Object
  java.io.InputStream
      com.enterprisedt.net.ftp.FileTransferInputStream
          com.enterprisedt.net.ftp.FTPInputStream

All Implemented Interfaces:

java.io.Closeable

public class FTPInputStream
extends FileTransferInputStream

Represents an input stream of bytes coming from an FTP server, permitting the user to download a file by reading the stream. It can only be used for one download, i.e. after the stream is closed it cannot be reopened.

Version:

$Revision: 1.5 $

Author:

Bruce Blackshaw

Field Summary

Fields inherited from class com.enterprisedt.net.ftp.FileTransferInputStream

closed, monitor, monitorCount, monitorEx, monitorInterval, pos, remoteFile, started

Constructor Summary

FTPInputStream(FTPClient client, java.lang.String remoteFile)
Constructor.

FTPInputStream(FTPClient client, java.lang.String remoteFile, long offset)
Constructor.

Method Summary

void	close() Closes this input stream and releases any system resources associated with the stream.
void	mark(int readlimit) Marks the current position in this input stream.
boolean	markSupported() Tests if this input stream supports the mark and reset methods.
int	read() Reads the next byte of data from the input stream.
int	read(byte[] b, int off, int len) Reads up to len bytes of data from the input stream into an array of bytes.
void	reset() Repositions this stream to the position at the time the mark method was last called on this input stream.
long	skip(long n) Skips over and discards n bytes of data from this input stream.

Methods inherited from class com.enterprisedt.net.ftp.FileTransferInputStream

checkMonitor, getRemoteFile, setMonitor

Methods inherited from class java.io.InputStream

available, read

Methods inherited from class java.lang.Object

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

Constructor Detail

FTPInputStream

public FTPInputStream(FTPClient client,
                      java.lang.String remoteFile)
               throws java.io.IOException,
                      FTPException

Constructor. A connected FTPClient instance must be supplied. This sets up the download

Parameters:

client - connected FTPClient instance

remoteFile - remote file

Throws:

java.io.IOException

FTPException

FTPInputStream

public FTPInputStream(FTPClient client,
                      java.lang.String remoteFile,
                      long offset)
               throws java.io.IOException,
                      FTPException

Constructor. A connected FTPClient instance must be supplied. This sets up the download. If an offset > 0 is supplied, must be a binary transfer.

Parameters:

client - connected FTPClient instance

remoteFile - remote file

offset - offset to resume downloading from.

Throws:

java.io.IOException

FTPException

Method Detail

read

public int read()
         throws java.io.IOException

Reads the next byte of data from the input stream. The value byte is returned as an int in the range 0 to 255. If no byte is available because the end of the stream has been reached, the value -1 is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.

Specified by:

read in class java.io.InputStream

Throws:

java.io.IOException

read

public int read(byte[] b,
                int off,
                int len)
         throws java.io.IOException

Reads up to len bytes of data from the input stream into an array of bytes. An attempt is made to read as many as len bytes, but a smaller number may be read, possibly zero. The number of bytes actually read is returned as an integer. This method blocks until input data is available, end of file is detected, or an exception is thrown.

Overrides:

read in class java.io.InputStream

Parameters:

b - array to read into

off - offset into the array to start at

len - the number of bytes to be read

Returns:

the number of bytes read, or -1 if the end of the stream has been reached.

Throws:

java.io.IOException

close

public void close()
           throws java.io.IOException

Closes this input stream and releases any system resources associated with the stream. This must be called before any other operations are initiated on the FTPClient.

Specified by:

close in interface java.io.Closeable

Overrides:

close in class java.io.InputStream

Throws:

java.io.IOException - if an I/O error occurs.

skip

public long skip(long n)
          throws java.io.IOException

Skips over and discards n bytes of data from this input stream. The skip method may, for a variety of reasons, end up skipping over some smaller number of bytes, possibly 0. This may result from any of a number of conditions; reaching end of file before n bytes have been skipped is only one possibility. The actual number of bytes skipped is returned. If n is negative, no bytes are skipped.

Overrides:

skip in class java.io.InputStream

Parameters:

n - the number of bytes to be skipped.

Returns:

the actual number of bytes skipped.

Throws:

java.io.IOException - if the stream does not support seek, or if some other I/O error occurs.

mark

public void mark(int readlimit)

Marks the current position in this input stream. A subsequent call to the reset method repositions this stream at the last marked position so that subsequent reads re-read the same bytes.

Overrides:

mark in class java.io.InputStream

Parameters:

readlimit - the maximum limit of bytes that can be read before the mark position becomes invalid.

See Also:

InputStream.reset()

reset

public void reset()
           throws java.io.IOException

Repositions this stream to the position at the time the mark method was last called on this input stream.

Overrides:

reset in class java.io.InputStream

Throws:

java.io.IOException - if this stream has not been marked or if the mark has been invalidated.

See Also:

InputStream.mark(int), IOException

markSupported

public boolean markSupported()

Tests if this input stream supports the mark and reset methods. Whether or not mark and reset are supported is an invariant property of a particular input stream instance. The markSupported method of InputStream returns false.

Overrides:

markSupported in class java.io.InputStream

Returns:

true if this stream instance supports the mark and reset methods; false otherwise.

See Also:

InputStream.mark(int), InputStream.reset()