java: Add guestfs-java(3) man page.

[libguestfs.git] / java / examples / CreateDisk.java

diff --git a/java/examples/CreateDisk.java b/java/examples/CreateDisk.java
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+// Example showing how to create a disk image.
+
+import java.io.*;
+import java.util.Map;
+import java.util.HashMap;
+import com.redhat.et.libguestfs.*;
+
+public class CreateDisk
+{
+    static String output = "disk.img";
+
+    public static void main (String[] argv)
+    {
+        try {
+            GuestFS g = new GuestFS ();
+
+            // Create a raw-format sparse disk image, 512 MB in size.
+            RandomAccessFile f = new RandomAccessFile (output, "rw");
+            f.setLength (512 * 1024 * 1024);
+            f.close ();
+
+            // Set the trace flag so that we can see each libguestfs call.
+            g.set_trace (true);
+
+            // Set the autosync flag so that the disk will be synchronized
+            // automatically when the libguestfs handle is closed.
+            g.set_autosync (true);
+
+            // Attach the disk image to libguestfs.
+            Map<String, Object> optargs = new HashMap<String, Object>() {
+                {
+                    put ("format", "raw");
+                    put ("readonly", Boolean.FALSE);
+                }
+            };
+            g.add_drive_opts (output, optargs);
+
+            // Run the libguestfs back-end.
+            g.launch ();
+
+            // Get the list of devices.  Because we only added one drive
+            // above, we expect that this list should contain a single
+            // element.
+            String[] devices = g.list_devices ();
+            if (devices.length != 1)
+                throw new Error ("expected a single device from list-devices");
+
+            // Partition the disk as one single MBR partition.
+            g.part_disk (devices[0], "mbr");
+
+            // Get the list of partitions.  We expect a single element, which
+            // is the partition we have just created.
+            String[] partitions = g.list_partitions ();
+            if (partitions.length != 1)
+                throw new Error ("expected a single partition from list-partitions");
+
+            // Create a filesystem on the partition.
+            g.mkfs ("ext4", partitions[0]);
+
+            // Now mount the filesystem so that we can add files.
+            g.mount_options ("", partitions[0], "/");
+
+            // Create some files and directories.
+            g.touch ("/empty");
+            String message = "Hello, world\n";
+            g.write ("/hello", message.getBytes());
+            g.mkdir ("/foo");
+
+            // This one uploads the local file /etc/resolv.conf into
+            // the disk image.
+            g.upload ("/etc/resolv.conf", "/foo/resolv.conf");
+
+            // Because 'autosync' was set (above) we can just close the handle
+            // and the disk contents will be synchronized.  You can also do
+            // this manually by calling g#umount_all and g#sync.
+            //
+            // Note also that handles are automatically closed if they are
+            // reaped by the garbage collector.  You only need to call close
+            // if you want to close the handle right away.
+            g.close ();
+        }
+        catch (Exception exn) {
+            System.err.println (exn);
+            System.exit (1);
+        }
+    }
+}