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Mike Schilling wrote:
> Arne Vajhøj wrote:
>>>> If we can assume that Java version >= 1.5, main thread has
>>>> thread id 1 and max. stack depth is 1000:
>>>>
>>>> StackTraceElement[] ste =
>>>> ManagementFactory.getThreadMXBean().getThreadInfo( 1,
>>>> 1000).getStackTrace(); String clznam =
>>>> ste[ste.length-1].getClassName();
>>> Is that really going to give you the class mentioned in the command
>>> line rather than the class which defines the static main() method?
>> You are correct. It returns the parent class where main is
>> defined.
>
> Right. My strong impression is that trying to figure out which subclass was
> mentioned in the command line is simply hopeless (or at best extremely
> non-portable) and that, accordingly, the OP should figure out some other way
> of doing things. Fortunately, there are dozens of them.

True.

JNI and an OS specific call is not a good solution.

Arne

On 15 Sep., 03:32, "Mike Schilling" <mscottschill...@hotmail.com>
wrote:
> Arne Vajhøj wrote:
> >>> If we can assume that Java version >= 1.5, main thread has
> >>> thread id 1 and max. stack depth is 1000:
>
> >>> * * * * StackTraceElement[] ste =
> >>> ManagementFactory.getThreadMXBean().getThreadInfo( 1,
> >>> * * * * 1000).getStackTrace(); String clznam =
> >>> ste[ste.length-1].getClassName();
>
> >> Is that really going to give you the class mentioned in the command
> >> line rather than the class which defines the static main() method?
>
> > You are correct. It returns the parent class where main is
> > defined.
>
> Right. *My strong impression is that trying to figure out which subclass was
> mentioned in the command line is simply hopeless (or at best extremely
> non-portable) and that, accordingly, the OP should figure out some other way
> of doing things. *Fortunately, there are dozens of them.

public static String getMainClassName()
{
for(final Map.Entry<String, String> entry : System.getenv().entrySet
())
{
if(entry.getKey().startsWith("JAVA_MAIN_CLASS"))
return entry.getValue();
}
throw new IllegalStateException("Cannot determine main class.");
}

On Oct 5, 11:41 am, Toffstier <mjcap...@gmail.com> wrote:
> public static String getMainClassName()
> {
> for(final Map.Entry<String, String> entry : System.getenv().entrySet
> ())
> {
> if(entry.getKey().startsWith("JAVA_MAIN_CLASS"))
> return entry.getValue();
> }
> throw new IllegalStateException("Cannot determine main class.");
> }

Thanks, but this doesn't work for me. Even trying to create the parent
class leads to an error being thrown.

$ java TestMain
Exception in thread "main" java.lang.IllegalStateException: Cannot
determine main class.
at TestMain.getMainClassName(TestMain.java:14)
at TestMain.main(TestMain.java:19)
$

Here are the keys available on my computer.

entry key is TERM
entry key is SSH_AGENT_PID
entry key is JAVA_HOME
entry key is SHLVL
entry key is JMFHOME
entry key is XFILESEARCHPATH
entry key is GDM_XSERVER_LOCATION
entry key is SESSION_MANAGER
entry key is COLORTERM
entry key is GNOME_DESKTOP_SESSION_ID
entry key is MAIL
entry key is GDMSESSION
entry key is HOSTNAME
entry key is PWD
entry key is FIREFOX_DSP
entry key is WINDOWID
entry key is KDEDIR
entry key is LOGNAME
entry key is G_BROKEN_FILENAMES
entry key is QTDIR
entry key is _
entry key is SSH_AUTH_SOCK
entry key is NLSPATH
entry key is GNOME_KEYRING_SOCKET
entry key is LD_LIBRARY_PATH
entry key is OLDPWD
entry key is SHELL
entry key is INPUTRC
entry key is DBUS_SESSION_BUS_ADDRESS
entry key is HISTSIZE
entry key is GTK_RC_FILES
entry key is CLASSPATH
entry key is PATH
entry key is JRE_HOME
entry key is DESKTOP_SESSION
entry key is DISPLAY
entry key is USER
entry key is DESKTOP_STARTUP_ID
entry key is HOME
entry key is PKG_CONFIG_PATH
entry key is LESSOPEN
entry key is XAUTHORITY
entry key is HTC_XML
entry key is LS_COLORS
entry key is LANG
entry key is SSH_ASKPASS

Here's the source code I used.


import java.util.*;

public class TestMain
{

public static String getMainClassName()
{
for(final Map.Entry<String, String> entry : System.getenv
().entrySet
())
{
System.out.println( "entry key is " + entry.getKey() );
if(entry.getKey().startsWith("JAVA_MAIN_CLASS"))
return entry.getValue();
}
throw new IllegalStateException("Cannot determine main class.");
}

public static void main( String args[] )
{
System.out.println( "main class is " + getMainClassName() );
}
}

Toffstier wrote:
> On 15 Sep., 03:32, "Mike Schilling" <mscottschill...@hotmail.com>
> wrote:
>> Arne Vajhøj wrote:
>>>>> If we can assume that Java version >= 1.5, main thread has
>>>>> thread id 1 and max. stack depth is 1000:
>>
>>>>> StackTraceElement[] ste =
>>>>> ManagementFactory.getThreadMXBean().getThreadInfo( 1,
>>>>> 1000).getStackTrace(); String clznam =
>>>>> ste[ste.length-1].getClassName();
>>
>>>> Is that really going to give you the class mentioned in the
>>>> command
>>>> line rather than the class which defines the static main()
>>>> method?
>>
>>> You are correct. It returns the parent class where main is
>>> defined.
>>
>> Right. My strong impression is that trying to figure out which
>> subclass was mentioned in the command line is simply hopeless (or
>> at
>> best extremely non-portable) and that, accordingly, the OP should
>> figure out some other way of doing things. Fortunately, there are
>> dozens of them.
>
> public static String getMainClassName()
> {
> for(final Map.Entry<String, String> entry :
> System.getenv().entrySet ())
> {
> if(entry.getKey().startsWith("JAVA_MAIN_CLASS"))
> return entry.getValue();
> }
> throw new IllegalStateException("Cannot determine main class.");
> }

How is JAVA_MAIN_CLASS getting set? It's not something the JVM does
automagically.