Cannot compile my Hello World

Question

Hello I am new to Java,
I am running openSUSE 11.1.
on running the javac compiler this is what I get.:
alon@linux-6xrt:~/java> javac Ch2Sample1.java
/usr/lib/gcc/i586-suse-linux/4.3/../../../crt1.o: In function `_start':
/usr/src/packages/BUILD/glibc-2.9/csu/../sysdeps/i386/elf/start.S:115: undefined reference to `main'
collect2: ld returned 1 exit status
alon@linux-6xrt:~/java> This is my java code
import javax.swing.*;
public class Ch2Sample1  {
     public static void main  (String [] args  )   {
     JFrame      myWindow;
     myWindow = new JFrame();
     myWindow.setSize(300, 300);
     myWindow.setTitle("My First Java ");
     myWindow.setVisible(true);
     System.out.print("Hello World");
}I am pretty much at a loss.

Answer 1

Thank you
I followed your advice and
javac -v
Using built-in specs.
Reading specs from /usr/lib/gcc/i586-suse-linux/4.3/libgcj.spec
rename spec startfile to startfileorig
rename spec lib to liborig
Target: i586-suse-linux
Configured with: ../configure --prefix=/usr --infodir=/usr/share/info --mandir=/usr/share/man --libdir=/usr/lib --libexecdir=/usr/lib --enable-languages=c,c++,objc,fortran,java --enable-checking=release --with-gxx-include-dir=/usr/include/c++/4.3 --enable-ssp --disable-libssp --with-bugurl=http://bugs.opensuse.org/ --with-pkgversion='SUSE Linux' --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-4.3-1.5.0.0/jre --with-ecj-jar=/usr/lib/gcc/i586-suse-linux/4.3/ecj.jar --enable-java-awt=gtk --enable-gtk-cairo --disable-libjava-multilib --disable-libmudflap --with-slibdir=/lib --with-system-zlib --enable-__cxa_atexit --enable-libstdcxx-allocator=new --disable-libstdcxx-pch --enable-version-specific-runtime-libs --program-suffix=-4.3 --enable-linux-futex --without-system-libunwind --with-cpu=generic --build=i586-suse-linux
Thread model: posix
gcc version 4.3.2 [gcc-4_3-branch revision 141291] (SUSE Linux)
alon@linux-6xrt:/usr/lib/jvm> I guess I am using gcj
BTW I am using openSUSE, I use geany editor and I type all the command the terminal.. no IDE for me.
I gather I should down the java compiler from Sun then?.
I have found this
java                        java-gcj       jre-1.6.0-openjdk
java-1.5.0                  jre            jre-gcj
java-1.5.0-gcj              jre-1.5.0      jre-openjdk
java-1.5.0-gcj-4.3-1.5.0.0  jre-1.5.0-gcj
java-1.6.0-openjdk-1.6.0    jre-1.6.0
alon@linux-6xrt:/usr/lib/jvm> So I guess I have the openjdk?
Your advice?