Re: Switching to Java on OS/400 - got a few questions.

[tballen@xxxxxxxxxx]

I'll attempt to answer a few questions.

I'm not familiar with the long startup time of Tomcat.
You can create native Java program objects on 
OS/400 with the CRTJVAPGM command.
Change the optimization level.  It is *INTERPRET by default.

You can run graphical applications using NAWT on OS/400 but it is not easy.
Below are some notes I have on this.  We never 
tried it but it may give you a place to start.

NAWT relies upon the X Window System for its 
graphics engine. The recommended X Window 
graphics server for this release is Virtual 
Network Computing (VNC), which runs under OS/400 
Portable Application Solutions Environment 
(PASE). PASE is a UNIX-like environment capable 
of running most binary executables compiled for 
IBM's AIX operating system. VNC is a product of 
AT&T Research Labs, and provides a virtual X 
Window server; that is, an X server that does not 
require a directly attached graphics-capable display device.

I've never heard of anyone using OS/400 as a development platform.

I've never found Java applications to be resource-intensive on OS/400.
Of course a badly written application could cause problems.

I am familiar with 2 JDBC drivers for DB2/400:
1) com.ibm.db2.jdbc.app.DB2Driver -> Use this 
when running a Java application locally on an iSeries (AS/400) machine
2) com.ibm.as400.access.AS400JDBCDriver -> Use 
this driver when accessing a remote iSeries (AS/400) system

I hope this helps.

Todd


At 02:02 PM 9/19/2005, Thorbjørn Ravn Andersen wrote:
> I am an experienced Javaprogrammer with 
> Windows+Unix experience who have now for a while 
> worked with creating frontends for OS/400 
> backbone calls using Eclipse on Win32.
>
> Just for fun I tried installing and running 
> Tomcat 5.0.30 beta the other day, with the 
> intent of eventually porting our webapps to run 
> natively on OS/400, but we are very careful since that is very new to us all.
> The sample JSP's and servlets was impressively quick!
>
> I would therefore like to hear if there is 
> experience in this forum regarding the following:
>
> * The long startup time of Tomcat (50 seconds) 
> is due to some precompilation to native code?
> * Can I use graphical applications (Swing) on 
> OS/400 and use some software on Win32/Unix to 
> see the output.  X Windows perhaps?
>
> * I have seen that some corners of eclipse.org 
> mention OS/400 binaries, but not for the native 
> Eclipse application.   Is this available, or is 
> it perhaps some Websphere package?   How do I 
> access that (i.e. what am I to ask the system 
> responsible) :)  Would Netbeans run?
>
> * Do anyone use Java on OS/400 as a development 
> platform, or is it solely for deploying applications?
>
> * I found the qsh interface rather sluggish to 
> work with.  Can I ssh to OS/400 instead and 
> perhaps get a more responsive shell?
>
> * What is the resource usage of Java programs 
> under OS/400?  How can I tell for myself?  It is 
> very important that we can determine accurately if this is a feasible path.
>
> * Do anyone have performance numbers of 
> JDBC-access using the best driver when running 
> on OS/400?  We may have a very data processing 
> intensive application where network performance 
> may be a bottleneck if running on another host.
>
>
>
> Any other suggestions, including further reading, would be appreciated.
>
> Thanks in advance for any pointers.
>
> Best regards,
>
>    Thorbjørn Ravn Andersen