ubuntu12.04给firefox浏览器安装java插件

参考地址：

Follow these instructions:（先安装）

1. Change the permission of the file you downloaded to be executable. Type:
   chmod a+x jre-7u-linux-i586.tar.gz
   where is to be replaced by the version downloaded.
   Example: For jre-7u3, the command is
   chmod a+x jre-7u3-linux-i586.tar.gz
2. Verify that you have permission to execute the file. Type:
   ls -l

3. Change to the directory in which you want to install. Type:
   cd
   For example, to install the software in the /usr/java/ directory, Type:
   cd /usr/java/
   
   Note about root access: To install Java in a system-wide location such as /usr/local, you must login as the root user to gain the necessary permissions. If you do not have root access, install the Java in your home directory or a subdirectory for which you have write permissions.

4. Unpack the tarball and install Java Type:
   % tar zxvf jre-7u-linux-i586.tar.gz
   
   The license agreement is displayed. Review the agreement. Press the spacebar to display the next page. At the end, enter yes to proceed with the installation.
   
   
5. Java is installed into its own directory. In this example, it is installed in the /usr/java/jre1.7.0_ directory. When the installation has completed, you will see the word Done.
   

6. Verify that the jre1.7.0_ sub-directory is listed under the current directory. Type:
   ls

 Firefox or Mozilla To configure the Java Plugin follow these steps:

1. Exit Firefox browser if it is already running.
2. Uninstall any previous installations of Java Plugin.
   Only one Java Plugin can be used at a time. When you want to use a different plugin, or version of a plugin, remove the symbolic links to any other versions and create a fresh symbolic link to the new one.
3. Create a symbolic link to the libnpjp2.so file in the browser plugins directory
   • Go to the plugins sub-directory under the Firefox installation directory
     cd /plugins
   • Create the symbolic link
     ln -s /lib/i386/libnpjp2.so
   
   Note: If you are upgrading your Java version then before creating new symbolic link you should remove old symbolic link to enable latest downloaded Java.
   
   To remove old symbolic link:
   type cd /plugins
   rm libjavaplugin_oji.so
   Example
   • If Firefox is installed at this directory:
     /usr/lib/
   • And if the Java is installed at this directory:
     /usr/java/
   • Then type in the terminal window to go to the browser plug-in directory:
     /usr/lib//plugin
   • Enter the following command to create a symbolic link to the Java Plug-in for the Mozilla browser.
     ln -s /usr/java//lib/i386/libnpjp2.so
   
   
4. Start the Firefox browser, or restart it if it is already up.
   
   In Firefox, type about:plugins in the Location bar to confirm that the Java Plugin is loaded. You can also click the Tools menu to confirm that Java Console is there.