cis 260: app dev i
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CIS 260: App Dev I. Chapter 1: Overview. 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 - PowerPoint PPT PresentationTRANSCRIPT
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