Ryan McDougall writes:
> I apologize if this question is too low level for this list, but I've
> spend the entire afternoon googling to no avail.
This is very much on-topic.
> I am trying to compile a simple SWT app using either Sun's Java or GCJ
> (preferably both) on my FC4 system. If I am successful at this (and the
> process is indeed complex), I don't mind writing up a tutorial for the
> Wiki or some such, in return.
>
> I have gcj and eclipse installed, as well as Sun's 1.5 JDK (java and
> javac are currently linked to Suns JVM, but I can change that back).
> short.
>
> Here are the current rpms that are relevant:
> libswt3-gtk2-3.1.0_fc-0.M6.22
> libgcj-4.0.0-8
> gcc-java-4.0.0-8
> java-1.4.2-gcj-compat-devel-1.4.2.0-40jpp_31rh
> java-1.4.2-gcj-compat-1.4.2.0-40jpp_31rh
>
> Here is the simple app source in a file called TestGui.java:
>
> import org.eclipse.swt.*;
>
> public class TestGui
> {
> public static void main (String [] args) {
> Display display = new Display ();
> Shell shell = new Shell (display);
> Label label = new Label (shell, SWT.CENTER);
> label.setText ("Hello_world");
> label.setBounds (shell.getClientArea ());
> shell.open ();
> while (!shell.isDisposed ()) {
> if (!display.readAndDispatch ()) display.sleep ();
> }
> display.dispose ();
> }
> }
>
> I have tried the following commands based on guesses based on online
> tutorials:
>
> $ gcj
> --classpath=/usr/share/eclipse/plugins/org.eclipse.swt.gtk_3.1.0.jar /usr/lib/eclipse/plugins/org.eclipse.swt.gtk_3.1.0.jar.so --main=TestGui TestGui.java -o Test
>
> Running Test gives me the following error:
>
> Exception in thread "main" java.lang.LinkageError: unexpected exception
> during linking: org.eclipse.swt.widgets.Display
> at java.lang.VMClassLoader.transformException(java.lang.Class,
> java.lang.Throwable) (/usr/lib/libgcj.so.6.0.0)
> at java.lang.VMClassLoader.resolveClass(java.lang.Class)
> (/usr/lib/libgcj.so.6.0.0)
> at java.lang.Class.initializeClass() (/usr/lib/libgcj.so.6.0.0)
> at TestGui.main(java.lang.String[]) (Unknown Source)
> at gnu.java.lang.MainThread.call_main() (/usr/lib/libgcj.so.6.0.0)
> at gnu.java.lang.MainThread.run() (/usr/lib/libgcj.so.6.0.0)
> Caused by: java.lang.NullPointerException
> at java.lang.VMClassLoader.resolveClass(java.lang.Class)
> (/usr/lib/libgcj.so.6.0.0)
> ...4 more
OK, I had to add one line at the start of your demo:
import org.eclipse.swt.widgets.*;
And I tried to run it:
$ gij -classpath /usr/share/eclipse/plugins/org.eclipse.swt.gtk_3.1.0.jar TestGui
Exception in thread "main" java.lang.UnsatisfiedLinkError: libswt-pi-gtk-3128: file not found
at java.lang.Runtime._load(java.lang.String, boolean) (/usr/lib/libgcj.so.6.0.0)
So, where is libswt-pi-gtk-3128 ? Bizzarrely, I found it in
$HOME/.eclipse/org.eclipse.platform_3.1.0/configuration/org.eclipse.osgi/bundles/59/1/.cp/os/linux/x86/libswt-pi-gtk-3128.so
(sorry, no, I have *no idea* why it's there)
And then I ran the test like this:
LD_LIBRARY_PATH=$HOME/.eclipse/org.eclipse.platform_3.1.0/configuration/org.eclipse.osgi/bundles/59/1/.cp/os/linux/x86 java -classpath /usr/share/eclipse/plugins/org.eclipse.swt.gtk_3.1.0.jar TestGui
which ran fine.
There is probably some more official way of getting the path to
libswt-pi-gtk-3128.so.
Andrew.
