How I created this?

To create the native SWT-lib I did following

1. Fetch swt-3.1-win32-win32-x86.zip, swt-nl.jar from[http://dev.eclipse.org/viewcvs/index.cgi/~checkout~/platform-swt-home/main.html]
2. Extract src.zip from swt-3.1-win32-win32-x86.zip to folder src and merge with swt-nl.jar but do not overwrite SWTMessages.properties
3. Apply changes to TableCursor.java and bring your SWTMessages_XX.properties uptodate.
4. Get impdef for creating libXXX.a from XXX.dll
5. Then I used a fast created Makefile and type make -f Makfilelib.

How to use this?

Use a makefile similar to this

#
# File for building exe
#
SRC = ${wildcard *.java}                         # your java sources
OBJ = ${subst /,_,${patsubst %.java,%.o,${SRC}}} # object files

EXE = main.exe # name of executable
MAIN = Main    #  class with "public static void main(String argv[])"

.PHONY: all clean

all: ${EXE} ${OBJ}

clean:
	rm -rf ${OBJ} ${EXE}

${OBJ}:
	gcj -fjni --classpath="swt.jar;." -c ${subst _,/,${patsubst %.o,%.java,$@}} -o $@

${EXE}: ${OBJ}
	gcj -fjni --classpath="swt.jar" --main=${MAIN} -o ${EXE} ${OBJ} -L. -lswt-win32-3138 -lswt