Installing Java under Ubuntu

After installing unxmit on a Ubuntu 11.4 system, I discovered that Java’s JRE was missing. The symptoms were these: I invoked ./unxmit and received a popup window.

These are the steps I took to install Java on my Ubuntu machine.

1. Download from Java from www.java.org.

2. Created a target directory to unpack the Java download. /opt/java/64

3. Moved the java download to the target directory.

4. Changed the file authorization for the java download

5. Unpacked the java download

6. Register /opt/java/64/jre1.6.0_27/bin/java as a new java executable.

7. Register /opt/java/64/jre1.6.0_27/bin/java as the java executable of choice.

Step 1: Download

Download Java from www.java.org; and clicked on “Downloads” on the red menu bar. The Oracle website presented the window below. Ubuntu’s documentation said to download the 32-bit or 64-bit self-extracting binary that does *not* have RPM in its name. When I double-clicked on the hyperlink, it saved jre-6u27-linux-x64.bin in ~/Downloads.

Steps 2 through7 are performed under a Terminal application. That is, from Ubuntu’s menu bar

Applications->Accessories->Terminal

Step 2: Create Target Library

cd /opt

sudo mkdir java

sudo mkdir 64

Thus, final directory is /opt/java/64

Step 3: Move Binary to /opt/java/64

sudo mv ~/Downloads/jre-6u27-linux-x64.bin .

Step 4: Change Authorization for Self-extracting Binary

sudo chmod 755 jre-su27-linux-x64.bin

Step 5 Unpacked the java download

sudo ./jre-6u27-linux-x64.bin

Step 6: Register new java executable.

sudo update-alternatives --install "/usr/bin/java" "java" "/opt/java/64/jre1.6.0_27/bin/java" 1

Step 7: Register java executable of choice.

sudo update-alternatives --set java /opt/java/64/jre1.6.0_27/bin/java

All Together: