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08/17/11 - Introduction to Java and OOP
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 | What is programming about?
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 | Computer as "answer" machine, need to know its language to ask it a question
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| What makes something a computer? Is a calculator a computer? A cell phone? What else?
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| Input (keyboard, mouse, trackpad, scanner, modem, microphone, ...)
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| Output (display, speaker, printer, modem, ...)
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| Short-term storage (RAM) -- How big?
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| Long-term storage (Hard disk, flash drive, ...) - How big?
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| What is a computer program?
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| Source code (high-level, human-readable)
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| Assembly and machine language (low-level, not easily human readable, not portable to different CPUs/OSs)
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| Byte code (Java - portable, JVM - Java Virtual Machine)
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| Compiler is a program which translates high-level source code into machine-runnable code (.exe or .class file)
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| .exe is run by CPU, .class file is run by JVM
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| Interpreter translates and executes program one line at a time (BASIC)
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| We use Oracle's Java SDK (Software Development Kit) and the BlueJ IDE (integrated development environment).
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| The latest version of the Java SDK and the BlueJ IDE can be obtained from BlueJ's website:
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| We focus on Object-Oriented Programming (OOP)
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| An approach to writing programs which has evolved out of experience to make robust programs
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| Program consists of modules which have particular attributes and capabilities
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| Simplifies programming (a program largely consists of collecting and manipulating suitable objects)
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| Relatively easy to make modifications and extensions
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| Demo of Shapes Project from BlueJ examples directory
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| Project contains classes (templates for objects) for Circle, Square, Triangle and Canvas.
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| Diagonal lines indicate the code needs to be compiled. Compile the class source code.
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| Instantiate a Circle (make an instance of a Circle => create a circle object from the Circle class).
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| Examine some of the circle object's methods.
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| Experiment with some of the methods (make visible, move left, right, up, down, change size, color,...).
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| Instantiate additional Circles -- make a picture of a target.
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| Instantiate a square and a triangle.
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| Notice the similarities and differences among the methods.
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| Make a picture something like the following:
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| Install Java on your home computer (if necessary)
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| Install BlueJ on your home computer
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| Draw a picture of a house something like this using the classes in the shapes project. Feel free to elaborate on this or make it very different.
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| Submit a picture of your result (by taking a screenshot) by emailing it to me at:
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