jdk 설치

http://deviantcj.tistory.com/432

http://www.webupd8.org/2012/01/install-oracle-java-jdk-7-in-ubuntu-via.html

Install Oracle Java 7 in Ubuntu via PPA

This package provides Oracle Java JDK 7 (which includes Java JDK, JRE and the Java browser plugin). However, you can't only install Oracle JRE - the PPA only provides the full Oracle JDK7 package.

To add our PPA and install the latest Oracle Java 7 in Ubuntu (supports Ubuntu 12.04, 11.10, 11.04 and 10.04), use the commands below:

sudo add-apt-repository ppa:webupd8team/java
sudo apt-get update
sudo apt-get install oracle-java7-installer

After the installation finishes, if you wish to see if it was successful, you can run the following command:

java -version

It should return something like this:

java version "1.7.0_04"
Java(TM) SE Runtime Environment (build 1.7.0_04-b20)
Java HotSpot(TM) Server VM (build 23.0-b21, mixed mode)

The package installs all the Java binaries, so you can also try "javac -version" which should return "javac 1.7.0_04" and so on (the "_04" part of the version can be different because I'm constantly updating the PPA with the latest Oracle Java 7 version).

If for some reason, the Java version in use is not 1.7.0, you can try to run the following command:

sudo update-java-alternatives -s java-7-oracle

Update: the installer now requires you accept the Oracle license before the installation begins. This is only required once. If for some reason you need the installation to be automated, you can run the following command to automatically accept the Oracle license:

sudo echo oracle-java7-installer shared/accepted-oracle-license-v1-1 select true | sudo /usr/bin/debconf-set-selections