# Installing Oracle JDK on Ubuntu: A Step-by-Step Guide for Java Developers

## Introduction

If you're a Java developer working with older projects that require an earlier version of the Development Kit (JDK), installing Oracle's official implementation can be challenging, especially when using recent versions like Ubuntu 12.04 Long Term Support (LTS). This article will walk through the process of manually downloading and setting up Oracle JDK on Ubuntu, bypassing the default package manager limitations.

## Why Use Oracle JDK?

While OpenJDK is a popular alternative provided by default in many Linux distributions, there are scenarios where you may prefer or require using the official Oracle implementation. Some reasons include:

* Compatibility issues with certain third-party libraries

* Need for features not yet available in OpenJDK

Regardless of your reason, follow these instructions to install and configure Oracle JDK 6 on Ubuntu.

## Prerequisites

Before starting:

1. Ensure you have an existing Java Development Kit (SDK) or a compatible version installed.

2. Make sure `sudo` privileges are enabled for the user performing this installation process.

### Step 1: Downloading Oracle JDK

1. Open your preferred web browser and navigate to 'Oracle's official download page'(https://www.oracle.com/java/technologies/jdk-6u45-linux-i586-super-jre.zip).

2. Scroll down to the 'JDK' section.

3. Click on the appropriate link for your architecture (32-bit or 64-bit) under 'jdk1_7_oracle_linux_i586_jdk-1_7-oracle-sol_rpm.tar.gz'.

4. Download and save it to a safe location, such as `Downloads` directory.

### Step 2: Removing Existing JDK Instances

To avoid potential conflicts:

1. Open the terminal application.

2. Change into the downloaded directory using `cd`.

3. List all existing Java installations with `sudo update-alternatives --display java`.

Example output:

```bash

java /usr/bin/java '2008-08-10-17:30' 3065 priority -1000

```

4. Remove the current default JDK by running:

```bash

sudo rm -rf /opt/jdk*

```

### Step3: Extracting and Configuring Oracle JDK

1. Navigate to your download directory using `cd`.

2. Uncompress the downloaded tarball with:

```bash

tar xvf jdk-6u45-linux-i586.tar.gz

```

3. Create a new directory for installing Oracle JDK:

```

sudo mkdir -p /opt/Oracle/jdk1_6_0_x

```

4. Move extracted contents into the newly created directory using:

```bash

mv jdk1.7.x//* /opt/Oracle/jdk1_6_0_x/

```

5. Create symbolic links to `bin` and `lib` directories:

```

sudo ln -s /opt/Oracle/jdk1_6_0_x/bin/{java, javac, javadoc} /usr/local/bin

```

### Step 4: Setting Up PATH Environment Variables

To ensure that the newly installed Oracle JDK is recognized by your system:

1. Open `~/.bashrc` or equivalent configuration file for your shell editor.

2. Add these lines at the end of the file:

```bash

export JAVA_HOME=/opt/Oracle/jdk1_6_0_x/

export PATH=$PATH:/usr/local/bin

```

3. Save and exit.

### Step 5: Verifying Oracle JDK Installation

To confirm that everything has been successfully set up:

1. Log out of your user account.

2. Reboot or restart the system using `sudo reboot`.

## You have now installed Oracle JDK on Ubuntu manually, bypassing potential issues with default package manager implementations. This guide assumes a basic understanding of Linux command-line operations and Java development concepts.

Remember that this is an older version (JDK 6), which will not receive official security updates or bug fixes from Oracle anymore. For production environments, it's highly recommended to use the latest supported versions available for your specific platform.

If you encounter any difficulties during these steps or have further questions about setting up and managing Java Development Kits on Ubuntu, feel free to ask in our comments section below!

Oracle jdk 6 ubuntu