Libguestfs - May 2011 - How to run the java demo code contained in libguestfs package ???

Hi all,
I would like to use libguestfs to manage the virtual disk images of virtual
machines on XenServer, which is a virtualization platform.
When I try to do some test of the Java codes contained in the libguestfs
package, the following error promped up:

Exception in thread "main" java.lang.UnsatisfiedLinkError: no
guestfs_jni in java.library.path
at java.lang.ClassLoader.loadLibrary(Unknown Source)
at java.lang.Runtime.loadLibrary0(Unknown Source)
at java.lang.System.loadLibrary(Unknown Source)
at com.redhat.et.libguestfs.GuestFS.<clinit>(GuestFS.java:44)
at test.GuestFS005Load.main(GuestFS005Load.java:27)

It seems that I need to build guestfs_jni before I could use libguestfs through
Java. But I am not clear how to get this "guestfs_jni".......
Does anybody know how to fix this problem? Thank you very very much!
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://listman.redhat.com/archives/libguestfs/attachments/20110523/616f2073/attachment.htm>

On Mon, May 23, 2011 at 03:05:28PM +0800, ?? wrote:
> I would like to use libguestfs to manage the virtual disk images of
> virtual machines on XenServer, which is a virtualization platform.
What version of libguestfs and where did you get it from?
> When I try to do some test of the Java codes contained in the libguestfs
package, the following error promped up:
> 
> Exception in thread "main" java.lang.UnsatisfiedLinkError: no
guestfs_jni in java.library.path
> at java.lang.ClassLoader.loadLibrary(Unknown Source)
> at java.lang.Runtime.loadLibrary0(Unknown Source)
> at java.lang.System.loadLibrary(Unknown Source)
> at com.redhat.et.libguestfs.GuestFS.<clinit>(GuestFS.java:44)
> at test.GuestFS005Load.main(GuestFS005Load.java:27)
> 
> It seems that I need to build guestfs_jni before I could use libguestfs
through Java. But I am not clear how to get this "guestfs_jni".......
> Does anybody know how to fix this problem? Thank you very very much!
If the *.so file is in some non-standard place, then you may need to
define java.library.path to be the directory containing
libguestfs_jni.so.1.  For example:

  java -Djava.library.path=/path/to/library Test

You may also need to set your classpath to contain the jar file.

On a Fedora host using the libguestfs-java Fedora package, I can run
libguestfs like this [see attachment for test program]:

  $ CLASSPATH=/usr/share/java/libguestfs-1.11.8.jar javac Test.java
  $ CLASSPATH=/usr/share/java/libguestfs-1.11.8.jar:. java Test
  $ virt-filesystems -a test.img --all --long
  Name         Type        VFS      Label  Size       Parent
  /dev/VG/LV1  filesystem  ext2     -      209715200  -
  /dev/VG/LV2  filesystem  unknown  -      209715200  -
  /dev/VG/LV1  lv          -        -      209715200  /dev/VG
  /dev/VG/LV2  lv          -        -      209715200  /dev/VG
  /dev/VG      vg          -        -      520093696  -
  /dev/sda     pv          -        -      520093696  -
  /dev/sda     device      -        -      524288000  -

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
New in Fedora 11: Fedora Windows cross-compiler. Compile Windows
programs, test, and build Windows installers. Over 70 libraries supprt'd
http://fedoraproject.org/wiki/MinGW http://www.annexia.org/fedora_mingw
-------------- next part --------------
import java.io.*;
import java.util.Map;
import com.redhat.et.libguestfs.*;

public class Test
{
    public static void main (String[] argv)
    {
        try {
            // Delete any previous test file if one was left around.
            File old = new File ("test.img");
            old.delete ();

            RandomAccessFile f = new RandomAccessFile ("test.img",
"rw");
            f.setLength (500 * 1024 * 1024);
            f.close ();

            GuestFS g = new GuestFS ();
            g.add_drive ("test.img");
            g.launch ();

            g.pvcreate ("/dev/sda");
            g.vgcreate ("VG", new String[] {"/dev/sda"});
            g.lvcreate ("LV1", "VG", 200);
            g.lvcreate ("LV2", "VG", 200);

            g.mkfs ("ext2", "/dev/VG/LV1");

            g.close ();
        }
        catch (Exception exn) {
            System.err.println (exn);
            System.exit (1);
        }
    }
}

[Please keep replies on the list]

On Mon, May 23, 2011 at 04:44:48PM +0800, ?? wrote:
> Thanks, I am using libguestfs-1.10.3, the stable release. But I
> can't find the libguestfs_jni.so.1 or the jar file from the package,
> where can I get one ?
Are you compiling from source?

In the standard build, libtool puts the libguestfs_jni.so* files in
"java/.libs" so you would use:

  java -Djava.library.path=.libs t/GuestFS005Load

(See java/run-java/tests)

The jar file should be built in the java/ directory.  However you
don't need it when running the tests because the JVM can find the
separate *.class files it needs from the current directory.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
virt-top is 'top' for virtual machines.  Tiny program with many
powerful monitoring features, net stats, disk stats, logging, etc.
http://et.redhat.com/~rjones/virt-top