Sockets in MS' JVM?

[Jesper Matthiesen]

Has anyone experienced problems(/solutions) with the use of sockets with
Microsofts JVM. I have to use it to avoid
users having to download the Sun Java plugin. So I'm compiling with:
javac -target 1.1 foo.java
I'm simply trying to connect to the localhost:

socket = new Socket("127.0.0.1", port);

*Nothing* happens..no exceptions!

Kind regards - Jesper

[Silvio Bierman]

"Jesper Matthiesen" <jmatthiesen[_fjen_]@tiscali.dk> wrote in message
news:p1*********************@news000.worldonline.d k...

Has anyone experienced problems(/solutions) with the use of sockets with
Microsofts JVM. I have to use it to avoid
users having to download the Sun Java plugin. So I'm compiling with:
javac -target 1.1 foo.java
I'm simply trying to connect to the localhost:

socket = new Socket("127.0.0.1", port);

*Nothing* happens..no exceptions!

Kind regards - Jesper

I take it you are talking about an applet? Opening a socket connection to
localhost is not allowed from an applet running under normal security mode.
It should give you a security exception in either JRE though.

Silvio Bierman

[Jesper Matthiesen]

[...]

I take it you are talking about an applet? Opening a socket connection to
localhost is not allowed from an applet running under normal security mode. It should give you a security exception in either JRE though.

[...]

Yes, sorry. I *am* talking about an applet. I was not aware that it is not
allowed to connect using the loopback address.
However, as you mention I haven't got any security exceptions from either of
the JVM's.
Thanks - Jesper

[Silvio Bierman]

"Jesper Matthiesen" <jmatthiesen[_fjen_]@tiscali.dk> wrote in message
news:uo*********************@news000.worldonline.d k...

[...]

I take it you are talking about an applet? Opening a socket connection to localhost is not allowed from an applet running under normal security mode.

It should give you a security exception in either JRE though.

[...]

Yes, sorry. I *am* talking about an applet. I was not aware that it is not
allowed to connect using the loopback address.
However, as you mention I haven't got any security exceptions from either

of the JVM's.
Thanks - Jesper

An applet is only allowed to communicate to the server that served the HTML
page it resides on. Have you tried your applet from different workstations?
Are you running it from a browser or are you using an appletviewer?

Silvio Bierman

[Jesper Matthiesen]

> An applet is only allowed to communicate to the server that served the
HTML

page it resides on. Have you tried your applet from different workstations? Are you running it from a browser or are you using an appletviewer?

Hi Silvio -
You were right! I was thinking that maybe the loopback could be seen as 'the
same machine' for test purposes even though we are actually making a
connection. However, I tried to catch the security Exception with:

catch(Exception e)
{
txt.append("Error: " + e + "\n");
}

but only

catch(SecurityException e)
{
txt.append("Error: " + e + "\n");
}

actually catches it (using Microsofts JVM). Shouldn't it be caught by the
first try+catch as well??
Thanks - Jesper

[Silvio Bierman]

"Jesper Matthiesen" <jmatthiesen[_fjen_]@tiscali.dk> wrote in message
news:8y*********************@news000.worldonline.d k...

An applet is only allowed to communicate to the server that served the HTML

page it resides on. Have you tried your applet from different

workstations?

Are you running it from a browser or are you using an appletviewer?

Hi Silvio -
You were right! I was thinking that maybe the loopback could be seen as

'the same machine' for test purposes even though we are actually making a
connection. However, I tried to catch the security Exception with:

catch(Exception e)
{
txt.append("Error: " + e + "\n");
}

but only

catch(SecurityException e)
{
txt.append("Error: " + e + "\n");
}

actually catches it (using Microsofts JVM). Shouldn't it be caught by the
first try+catch as well??
Thanks - Jesper

I would have expected SecurityException to be an Exception. You could try
catching a Throwable since that would always catch any exception thrown.
Exception is a Throwable subclass.

Silvio Bierman

[Jesper Matthiesen]

"> I would have expected SecurityException to be an Exception. You could try

catching a Throwable since that would always catch any exception thrown.
Exception is a Throwable subclass.

My point exactly. I haven't tried that yet, but SecurityException is indeed,
as you write, an exception. In Sun JVM v. 1.4.xx the security exception is
not thrown at all.
Regards Jesper

[Silvio Bierman]

"Jesper Matthiesen" <jmatthiesen[_fjen_]@tiscali.dk> wrote in message
news:3I*********************@news000.worldonline.d k...

"> I would have expected SecurityException to be an Exception. You could try

catching a Throwable since that would always catch any exception thrown.
Exception is a Throwable subclass.

My point exactly. I haven't tried that yet, but SecurityException is

indeed, as you write, an exception. In Sun JVM v. 1.4.xx the security exception is
not thrown at all.
Regards Jesper

Have you in any way tweaked the settings of the Sun JVM to reduce the
security restriuctions?

Silvio Bierman