jsch-users

[JSch-users] problem with ChannelSftp.get() -> InputStream.read()

[Joe B. <jbu...@gm...>]

I believe there may be an issue with the implementation of the
InputStream returned from ChannelSftp.get().  When reading the stream
byte by byte, the end-of-file condition is never set.  The Java spec
states that -1 should be returned if the end of the stream is reached.
http://java.sun.com/j2se/1.5.0/docs/api/java/io/InputStream.html#read()

It looks like the bitwise AND will truncate the negative value before retur=
ning:

// ChannelSftp.java ~line 803 in jsch-0.1.22-rc12
public int read() throws java.io.IOException{
            read(_data, 0, 1);
            return _data[0]&0xff;
          }


I've modified the code to return -1 when reached and it seems to work prope=
rly:

// return -1 explicitly when reached
public int read() throws java.io.IOException{
  int i =3D read(_data, 0, 1);
  if (i =3D=3D -1) { return -1; }
  else {
     return _data[0]&0xff;
  }
}

I believe the other read(*) methods work properly.

Joe

Re: [JSch-users] problem with ChannelSftp.get() -> InputStream.read()

[<ym...@jc...>]

Hi,

   +-From: Joe Buckshin <jbu...@gm...> --
   |_Date: Mon, 3 Oct 2005 11:15:48 -0400 ______
   |
   |It looks like the bitwise AND will truncate the negative value 
   |before returning:
   |// ChannelSftp.java ~line 803 in jsch-0.1.22-rc12
   |public int read() throws java.io.IOException{
   |            read(_data, 0, 1);
   |            return _data[0]&0xff;
   |          }

Oops, you are right.  Thank you for your feedback.  
It will be fixed in the next release.

Thanks,
--
Atsuhiko Yamanaka
JCraft,Inc.
4-1 OHMACHI 1-CHOME AOBA-KU,
SENDAI, MIYAGI 980-0804 Japan.
Tel +81-22-723-2150
    +1-415-578-3454
Fax +81-22-224-8773
Skype callto://jcraft/