CIS 260: App Dev I

CIS 260: App Dev I

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IT and Computer Systems

Important changes in information technology (IT)– Newspapers WWW– Snail mail email– Typewriter _____________– Brick & mortar e-commerce

Two major components of a computer system:– Hardware: run by software– Software: created/used by people

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History of Computers See

http://sunsethigh.dade.k12.fl.us/sunset/history/index.htm for a good history.

A brief history:– 1950s: emergence of mainframes– 1960s: widespread use of mainframes– 1970s: widespread use of minicomputers– 1980s: ____ become popular– 1990s: notebooks, Internet become popular– 2000s: E-commerce, wireless become

popular

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Tasks Performed by Computers

Input– Human (e.g., keypunch, mouse)– Automated (e.g., barcode, RFID)

Output– Human readable– Non-human readable

Storage– Primary– Secondary

Operations– Arithmetic– ____________

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Hardware CPU

– Control unit, arithmetic logic unit, instruction register, program counter

Main memory– Memory cells with addresses– RAM, ROM– Holds programs and data– Volatile

__________ storage– Hard disk, floppy disk, CD-ROM, flash drive

I/O– Input: keyboard, mouse, screen, scanner– Output: printer, monitor, speaker

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Software

System programs– Operating system

• Windows Explorer• Control Panel

Application programs– Word processor– Spreadsheet– Internet browser– ERP (__________

resource planning)– Games

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Computer Languages Signals

– Analog: changes are continuous (audio tape)– _______: changes are discrete, on/off (music

CD) Computer codes

– Binary digit (bit): a 0 or 1 (off/on), base 2– Byte: 8 _____ (00000001, 00000010, …)– ASCII code: 128 characters (27), nearly a

byte– EBCDIC: 256 characters (28), one byte– Unicode: 65,536 characters (216), two bytes

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Programming Languages Machine languages

– instructions in codes with 0s and 1s– Depends on type of CPU– Codes used for memory locations, operations

Assembly languages– ___________ used for instructions– 100100 means LOAD, 100101 means ADD– Assembler translates AL to ML

High-level languages (C, C++, Java)– Compiler converts Java to bytecode– ________ (JVM) converts bytecode to ML

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Processing a Java Program Programmer creates ______ code in an editor

– Type the Java code as a text file– Save the text file as <ClassName>.java

Compile the source code into __________– Source code MUST follow Java syntax– Compiler creates the bytecode in

<ClassName>.class Link the bytecode to other programs

– The Java library contains additional programs– A linker links your bytecode to create executable

code Run the executable program

– Loader loads executable into main memory– __________ translates executable code into ML

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Programming Process

Java Integrated Development Environments (IDE’s)– Forte– JBuilder– NetBeans– BlueJ

Programming Aids– Flowcharts: graphic– ____________: textual,

non-executable

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Programming Methodologies

Structured programming– Divide a problem into procedures– Use basic programming structures

• Sequence: do A, do B, do C, …• Selection: if…then• Loop: automated repetition

________-oriented programming (OOP)– Represent a problem as interacting objects– Determine the objects’ attributes– Determine the objects’ behaviors

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Introduction to Java Java was created in 1996 by _______. JDK is the Java _________, where “JDK”

stands for __________ Development Kit. Java syntax is similar to that of _______. Java was designed to run on any

computer _________ (i.e., combination of operating system and microprocessor).

Java applications run slightly _______ than most others.

Java handles internal memory overhead ______________.

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Applications, Applets, & Servlets

Java can be used to create ____________ that often have a GUI (_________ user interface).

Java can be used to create web-based applications called __________.

A Java server-side application is called a __________.

You can copy the applications from the text CD by running the OO_Java_Source_Code.zip file.

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How Java Compiles & Interprets

You can use a text ________ to create Java ________ code (.java file extension).

The Java __________ converts the source code into Java _________.

A platform that has a Java __________ (a.k.a. a Java _______ machine or JVM) can translate the bytecodes into the processor’s (machine) language.

A web browser with a Java interpreter can download and run Java ________.

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Installing the JDK

Using the CD that comes with the text,– Simply navigate to the Java folder (in the

Software folder), double-click the .exe file.– Follow the prompts.

Using the www.java.sun.com web site,– Select the download link for Java SE

(Standard Edition).– Download (can take a long time and can

contain errors).– Run the .exe file and follow the prompts.

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Directories & Files of the SDK

In the c:\jdk1.6.x directory,– bin contains the Java _________ and other

necessary tools for developing and testing– demo contains sample applications and

________– include contains header files for using ____

code in Java applications– jre contains the Java __________ or Java

Runtime Environment– lib contains libraries and support files– doc contains _____________

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To Configure Windows Select Start, Settings,

Control Panel. Select System,

Advanced tab, and Environment Variables button).

Select Path under System variables, Edit…

At the end of the current path, enter a “;” and add c:\jk1.6.x\bin\ (replace x with the current #)

If the system has a classpath variable, add “;.;” at the end.

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Creating a Java Program Run Notepad (Start, Programs, Accessories,

Notepad). Enter Java code (exactly), such as

public class MyFirstJavaProgram {

public static void main( String[ ] args )

{

System.out.println(“Hello world!”);

}

}

Remember!!! Java is ______-sensitive. Save the file as “MyFirstJavaProgram.java”,

say, in a folder called “first” on the a:\ drive (use the quotes on the file name).

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Compiling and Running

Run the Command Prompt (Start, Programs, Accessories, Command Prompt).

To ________, at the C:\> prompt, enter the following:a:javac \first\MyFirstJavaProgram.java

To _____, at the A:\> prompt, enter the following:cd\firstjava MyFirstJavaProgram

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Errors

You may get compile-time errors or run-time errors.

The JDK will provide the line _______ of the error, a description, and the actual code that is in error.

You will need to go back to _________ to correct the errors, recompile, and rerun.

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Creating a Java File w/ TextPad

TextPad is a text _______ designed for Java. To install TextPad go to

http://www.textpad.com/download/index.html#downloads

and select English, FTP (USA) To run TextPad…

– click Start, Programs, TextPad To create a Java program…

– enter Java code – select File, Save As… – enter the file name (matches the class name)– select Java as file type, OK.

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To Compile and Run w/ TextPad To compile…– Select Tools, Compile Java (or Ctrl+1)

To run…– Select Tools, Run Java Application (or Ctrl+2)

To view line numbers of code…– Select Configure, Preferences, View

What’s wrong with using a complex IDE (___________ Development Environment) in an introductory course?– Interferes with learning how to write pure

Java code– Wastes precious time learning the IDE