For Windows Users-bluejsetup-304.exe
For Mac Users-BlueJ-304.zip
For Debian, Ubuntu and other Debian-based systems-bluej-304.deb
For all other systems (executable jar file) -bluej-304.jar
Installation
Windows:
Double-click the install file (bluejsetup-304.exe).
This will run a standard installation. Follow the instructions on screen. The installer will install the executable bluej.exe. Execute this to run BlueJ.
When executing BlueJ you might get dialog from the firewall asking you whether you want to block or unblock BlueJ. It should be safe to keep blocking.
If you have more than one Java version installed, BlueJ will let you select your preferred version the first time it is executed. This can be changed later by running the "vmselect" program, which will be installed into the same directory as BlueJ.
Macintosh:
Note: BlueJ requires Java 6. Updating to the latest Java version (via the Mac OS Software Update feature) is recommended.
Download and expand the install file (BlueJ-304.zip). Move the resulting folder to your preferred location (for example Applications).
Debian, Ubuntu, and other Debian-based systems
Check your distribution's instructions on how to install "deb" packages. In many cases it will be as simple as double-clicking the downloaded file from within a file manager, and then providing an administrator password to allow the installation to proceed.
Note the "deb" package requires one of the following packages to be installed:
sun-java6-jdk or openjdk-6-jdk
However, we recommend installing "sun-java6-jdk" before installing BlueJ.
Please note, the example projects will be installed under /usr/share/doc/BlueJ/
On Ubuntu "Lucid Lynx" (10.04), the Sun JDK is no longer part of the multiverse section of the Ubuntu archive. To install it, you should open the Synaptic package manager, go to "Settings", "Repositories", "Other Software" tab, and enable the "lucid partner" repository, then close the dialog and press "Reload" in the main window; after completing these steps, it should be possible to install the "sun-java6-jdk" package.
Thanks to Joe Lewis for providing the initial version of the .deb package.
Unix:
Make sure you have a suitable JDK. The Sun JDKis recommended as it is the most tested. Currently the "gij" (GNU java interpreter) cannot be used.
Run the installer by executing (from the command shell)
/path/to/jdk/bin/java -jar bluej-304.jar
... where "/path/to/jdk" should be replaced by the actual path to the JDK.
Note: if you have a suitable java binary in a directory listed in your PATH environment variable, you may be able to omit the "/path/to/jdk" above. Be careful that this does not run an incompatible java implementation (such as "gij") however! You can check if a Java implementation is in your path by runng "java -version".
In the installer, select an installation directory and your JDK directory and install. By default, the installer will install into a directory called "bluej" inside the directory from which you launch it, and it will pick up the JDK location automatically (if it is run correctly according to the instructions above).
In the directory where BlueJ was installed, you will find a file named bluej. This is the launcher script. Execute this script to start BlueJ. For example:
cd bluej # change into installation directory
./bluej # execute the "bluej" launcher script
Note: This installer can be executed on any system with Java installed (including Windows and MacOS), but Windows/MacOS specific icons and configurations will not be present.
Optional: Remove the Installer
If you do not want to make further installations, you can now delete the installer file.
Opening a project
After starting BlueJ, open a project by selecting "Open" from the Project menu. You can find some examples in the "examples" directory. After the project has been opened, right-clicking (Mac: control-clicking) a class lets you select a constructor from a pop-up menu to construct an object.
SYSTEM REQUIREMENTS
Note that only the version labeled JDK will work. Not the one labeled JRE, nor the one that comes with NetBeans, nor the EE version.
Debian/Ubuntu users should install the JDK via the package management system rather than using the links above. See the installation instructions.