1. Bluej Java Programming App
2. Download Blue Java
3. Blue Jeans
4. Bluejay

Start BlueJ by either clicking on the icon you created when you downloaded and installed BlueJ or by navigating to the BlueJ directory and double clicking on the bluej.bat icon. You can alter some of the defaults for BlueJ my modifying the file called bluej.defs with a text editor.This file is located in the lib directory in the bluej folder. If you're new to Java programming then BlueJ is an excellent introductory Java environment designed specifically for introductory teaching. BlueJ is a fully integrated environment featuring everything you'd expect from a Java environment including graphical and textual editing, a built-in editor, compiler, virtual machine, debugger and interactive object creation. 'Objects First with Java: A Practical Introduction Using BlueJ' is a textbook co-written by the developers of BlueJ and has sold hundreds of thousands of copies worldwide. Teacher support Our free Blueroom website offers teaching resources and the chance to engage with other educators using BlueJ around the world.

BlueJ is an integrated development environment (IDE) for the Java programming language, developed mainly for educational purposes, but also suitable for small-scale software development. It runs with the help of JDK (Java Development Kit).

BlueJ was developed to support the learning and teaching of object-oriented programming, and its design differs from other development environments as a result.^[2] The main screen graphically shows the class structure of an application under development (in a UML-like diagram), and objects can be interactively created and tested. This interaction facility, combined with a clean, simple user interface, allows easy experimentation with objects under development. Object-oriented concepts (classes, objects, communication through method calls) are represented visually and in its interaction design in the interface.

History[edit]

Bluej Java Programming App

The development of BlueJ was started in 1999 by Michael Kölling and John Rosenberg at Monash University, as a successor to the Blue^[3] system. BlueJ is an IDE (Integrated Development Environment). Blue was an integrated system with its own programming language and environment, and was a relative of the Eiffel language. BlueJ implements the Blue environment design for the Java programming language.

In March 2009, the BlueJ project became free and open source software, and licensed under GNU GPL with the classpath exception.

BlueJ is currently being maintained by a team at King's College London, England, where Kölling works.

Functionality[edit]

Download Blue Java

BlueJ has a simpler interface than most professional IDEs, but its functionality is not a subset of those kinds of environment. While many of the standard development tools exist, such as an editor, compiler and runtime environment, it also offers tools that are specific to its educational goals and not found in this form in common professional environments. These includes interactive object creation and method invocation (via the 'Object Bench'), simplified debugging and teamwork controls, interactive, line-based expression and statement evaluation (via the 'Code Pad'), and automated creation of JUnit classes from recordings of interactive test sequences.

Visualisation[edit]

The BlueJ interface emphasises class structure (in preference of source code) by showing a UML-like diagram as its main screen. Class structures can be manipulated by the user, and the class relation display is generated automatically from the source code.

Source level structure is visualised through scope highlighting (the visual emphasis of lexical scope through use of graphical frames and background colour).

Interaction and experimentation[edit]

Supported interaction features include the ability to create objects interactively for ad-hoc testing and experimentation, and support for interactive invocation of public methods. Parameters may be passed and objects can be composed in interactive calls.

Interactive tests may be recorded and stored as standard unit test classes. Code fragments can be evaluated interactively in the Code Pad, which provides a Java-based REPL.

Blue Jeans

Supported languages[edit]

BlueJ supports programming in Java and in Stride.^[4] Java support has been provided in BlueJ since its inception, while Stride support was added in 2017.

See also[edit]

References[edit]

1. ^'Version History'. Retrieved 2019-08-12.
2. ^'Using BlueJ to Introduce Programming'(PDF). Retrieved 2010-06-13.
3. ^'An Object-Oriented Program Development Environment for the First Programming Course'(PDF). Retrieved 2018-09-17.
4. ^Stride

Bibliography[edit]

• Barnes, David J.; Kölling, Michael (May 12, 2011). Objects First with Java: A Practical Introduction Using BlueJ (5th ed.). Prentice Hall. p. 560. ISBN978-0-13-249266-9.
• Kölling, Michael; Quig, Bruce; Patterson, Andrew; Rosenberg, John (Aug 9, 2010). 'The BlueJ System and its Pedagogy'. Computer Science Education. 13 (4): 249–268. CiteSeerX10.1.1.22.3975. doi:10.1076/csed.13.4.249.17496.

External links[edit]

You need to have downloaded and installed BlueJ before completing the following steps.

1. Download the java files you need from the class web site. You don't have to put them in the BlueJ folder, just remember where you download them to on your computer. In this example I will assume they have been downloaded to the desktop.
   
2. Start BlueJ by either clicking on the icon you created when you downloaded and installed BlueJ or by navigating to the BlueJ directory and double clicking on the bluej.bat icon.

Bluejay

3. You can alter some of the defaults for BlueJ my modifying the file called bluej.defs with a text editor.This file is located in the lib directory in the bluej folder. You can also modifying the template that starts when creating new programs and classes. The template is stored in the lib -> english -> templates -> newclass folder.
   

4. When BlueJ is up and running you should see a window that looks something like this:
   
   

   To create a new program you first need to create a new project. Click on the Project menu and select New Project...
   
   

5. This opens a new window.
   From this window type in the name of the new project in the text field File name. The name of the project does not have to be the same as the name of the java file you will later add to the project. It can be anything you want.
   

6. After giving the new project and name and clicking Create you see the new project.
   There aren't any classes, which are the basic building blocks of programs in Java, or code associated with the project yet. The icon that looks like a piece of paper is just a simple text file that acts as the projects readme file. You can double click on it to add comments about the project as a whole or write notes to yourself on things that need to be done. You probably won't use it much at first.
   

7. If you need to add any pre-existing classes to the project now is a good time to do that. On the first assignment you need to download and add then add the DrawingPanel.java class to your project. To add the existing file to the project click on the Edit menu and then select Add Class from File...
   

8. A new window pops up that allows you to navigate to the correct directory and select the file you want to add. Only files that end in .java are shown.
   Navigate to the directory that contains the file or files you want to add. If you want to add a single file, click on it and then click on the Add button. If you want to add 2 or more files from the same directory hold down the CTRL key and click on all the files you want to add, then click on the Add button.
   

9. Now the new file / class has been added to the file. It shows up with diagonal lines because it has not been compiled yet.
   

10. To compile a class that is part of a program you can either click the Compile button on the left side of the window or right click on the icon of the class and select the Compile option from the pop up menu.
    If the class does not have any syntax errors it will now be shown without any diagonal lines on its icon.
    

11. To add a new class to the project click on the New Class button.
    

12. A menu pops up asking for the name of the class. On assignment 1 the name must be Circle.
    Ensure the Class radio button is selected, type in Circle for the Class Name and click the okay button. A new class is added to our project.
    

13. To edit the code in a class double click on its icon. This opens an editor window which is very like a simple word processor.
    Select and delete the default code in the class.
    

14. Type in the changes to the program. You save the program by clicking on the Class menu and selecting Save. You can attempt to compile the program by clicking the Compile button. Any errors will show up in the text area at the bottom of the edit window. If an error occurs the line the error is on is highlighted in yellow. After compiling the program and getting it to work close the editing window w and go back to the project window. The program / class icon no longer has diagonal lines across it.
    

15. To run the program right click on the icon that has the main method in it. IN assignment one, this is the Circle class. This brings up a menu that allows you to carry out various actions. (You could also compile classes here.) Select the menu option void main(args). This causes the main method of the class to be executed.
    

16. Another menu pops up that asks what parameters or information you want to pass to the method, in this case main. In this class we won't normally pass any information to method main so just click Ok.
    

17. This causes the program to run. In assignment 1 a separate window opens and you may have to click on that window to see the program run.
    For more help with BlueJ see the BlueJ tutorial and BlueJ reference manual.

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