[root@alik downloads]# rpm -q jdkjdk-1.6.0_12-fcs

The Java plug-in is part of the Java Runtime Environment (JRE), but Opera does not use the plug-in: it uses the JRE directly. To get Java working with Opera, you must install the JRE, and configure Opera with the correct Java path.

Before proceeding, you may wish to test Java to see if Opera has been able to auto-detect your Java installation using our test applet. If Opera does not show this applet (an animated analog clock), you must install the JRE and/or configure Opera with the correct Java path:
Download the Java Runtime Environment that is suitable for your system. For systems that are older than the ones listed in System Requirements on the download page, you will need version 1.3.1. Follow the installation instructions linked from the download page.
Go to Tools > Preferences > Advanced > Content, and click the "Java options" button. If this button is dimmed, first check the "Enable Java" option.
Click the "Choose" button for the "Java path" field. The path you are looking for is the directory of your Java installation containing the files libjava.so and libawt.so, for example /usr/lib/jvm/java-6-sun-1.6.0.03/jre/lib/i386 on an Ubuntu system. The command line tools indicated above should locate the directory.
Click the "Validate Java path" button. If you get an error message, try again with a different path.
Click "OK" to save your changes and exit the Java dialog. Click "OK" to save your changes and exit the Preferences dialog.