Voilà c'est résolu :-D grâce ce superbe fichier qu'il faudrait placer bien en évidence dans un wiki! :
http://www.mjmwired.net/resources/mjm-fedora-f17.html#java
Java Runtime Environment
12 June 2012
Fedora should include support for Java via OpenJDK (based on the Oracle Java) and Icedtea web plugin. However if not, they can be installed using YUM:
[mirandam@charon ~]$ sudo yum install java-1.7.0-openjdk icedtea-web
With OpenJDK/Icedtea installed, Java application and Web applets should automatically work. Unfortunately some applets may not run properly and the OpenJDK might have some limitations. Majority of user should find OpenJDK perfect for everyday use.
Using Oracle Java Instead
If you require Oracle Java or if OpenJDK does not work properly, you can download Sun Oracle Java and use it in Fedora.
Download the Java package from:
http://www.oracle.com/technetwork/java/javase/downloads/index.html.
Under Java Platform, Standard Edition, Select: Download JRE (the JDK is for Java developers)
On the next page, accept the license agreement, then:
For 32-bit users: select "Linux x86"
jre-7u5-linux-i586.rpm
For 64-bit users: select "Linux x64"
jre-7u5-linux-x64.rpm
To install:
[mirandam@charon Download]$ sudo rpm -ivh jre-7u5-linux-i586.rpm
-OR-
[mirandam@charon Download]$ sudo rpm -ivh jre-7u5-linux-x64.rpm
When running the java command, Fedora will default to using OpenJDK. In order to use Sun Java, use the alternatives command.
To setup the Java runtime, perform the following (applies to both 32-bit and 64-bit users):
[mirandam@charon Download]$ sudo /usr/sbin/alternatives --install /usr/bin/java java /usr/java/default/bin/java 20000
Setup the Mozilla/Firefox browser plugin:
For 32-bit users:
[mirandam@charon Download]$ sudo /usr/sbin/alternatives --install /usr/lib/mozilla/plugins/libjavaplugin.so \
libjavaplugin.so /usr/java/default/lib/i386/libnpjp2.so 20000
For 64-bit users:
[mirandam@charon Download]$ sudo /usr/sbin/alternatives --install /usr/lib64/mozilla/plugins/libjavaplugin.so \
libjavaplugin.so.x86_64 /usr/java/default/lib/amd64/libnpjp2.so 20000
You may need to restart Firefox to see the plugin take effect.
To Update: If you wish update the JRE package, simply download the newest RPM package and install it as above. You will NOT need to reset alternatives, as those settings should remain intact. The following is all that should be needed (64-bit example):
[mirandam@charon Download]$ sudo rpm -ivh jre-7u6-linux-x64.rpm
More Information: Install Documentation for Linux.