Post on 24-May-2015
description
Introduction toJava Programming
Y. Daniel LiangEdited by Hoàng Văn Hậu – VTC Academy – THSoft co.,ltd
https://play.google.com/store/apps/developer?id=THSoft+Co.,Ltd
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Introduction
Course Objectives Organization of the Book
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Course Objectives Upon completing the course, you will understand
– Create, compile, and run Java programs
– Primitive data types
– Java control flow
– Methods– Arrays (for teaching Java in two semesters, this could be the end)
– Object-oriented programming
– Core Java classes (Swing, exception, internationalization, multithreading, multimedia, I/O, networking, Java Collections Framework)
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Course Objectives, cont.
You will be able to – Develop programs using Eclipse IDE– Write simple programs using primitive data
types, control statements, methods, and arrays.– Create and use methods– Write interesting projects
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Session 01 Introduction to Java and Eclipse
What Is Java? Getting Started With Java Programming
– Create, Compile and Running a Java Application
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What Is Java? Java language programming market
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History James Gosling and Sun Microsystems
Oak
Java, May 20, 1995, Sun World
HotJava – The first Java-enabled Web browser
JDK Evolutions
J2SE, J2ME, and J2EE (not mentioned in the book, but could discuss here optionally)
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Characteristics of Java Java is simple
Java is object-oriented
Java is distributed
Java is interpreted
Java is robust
Java is secure
Java is architecture-neutral
Java is portable
Java’s performance
Java is multithreaded
Java is dynamic
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Java IDE Tools Forte by Sun MicroSystems Borland JBuilder
Microsoft Visual J++
NetBean by Oracle
IBM Visual Age for Java
Eclipse by Sun MicroSystems
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Getting Started with Java Programming
A Simple Java Application
Compiling Programs
Executing Applications
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A Simple Application
Example 1.1//This application program prints Welcome//to Java! package chapter1;
public class Welcome { public static void main(String[] args) { System.out.println("Welcome to Java!"); }}
RunRunSourceSource
NOTE: To run the program, install slide files on hard disk.
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Creating and Compiling Programs
On command line– javac file.java
Source Code
Create/Modify Source Code
Compile Source Code i.e. javac Welcome.java
Bytecode
Run Byteode i.e. java Welcome
Result
If compilation errors
If runtime errors or incorrect result
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Executing Applications
On command line– java classname
JavaInterpreter
on Windows
JavaInterpreter
on Sun Solaris
JavaInterpreteron Linux
Bytecode
...
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Example
javac Welcome.java
java Welcome
output:...
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Compiling and Running a Program
Where are the files stored in the directory?
c:\example
chapter1 Welcome.class
Welcome.java
chapter2
.
.
.
Java source files and class files for Chapter 2
chapter19 Java source files and class files for Chapter 19
Welcome.java~
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Anatomy of a Java Program Comments Package Keywords Variables – Data type Operators Control flow If else statement
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Comments
Eclipse shortcut key:Ctrl + Shift + C
Ctrl + Shift + /
Ctrl + /
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Package
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Keywords (reserved words)
http://en.wikipedia.org/wiki/List_of_Java_keywords
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Blocks
A pair of braces in a program forms a block that groups components of a program.
public class Test { public static void main(String[] args) { System.out.println("Welcome to Java!"); } }
Class block
Method block
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Data Types
byte 8 bits
short 16 bits
int 32 bits
long 64 bits
float 32 bits
double 64 bits
char 16 bits
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Constants
final datatype CONSTANTNAME = VALUE;
final double PI = 3.14159;
final int SIZE = 3;
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Operators
+, -, *, /, %, ++, --, +=, -=, *=, /=, ^, &, |
5/2 yields an integer 2.
5.0/2 yields a double value 2.5
5 % 2 yields 1 (the remainder of the division)
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Arithmetic Expressions
)94
(9))(5(10
5
43
y
x
xx
cbayx
is translated to
(3+4*x)/5 – 10*(y-5)*(a+b+c)/x + 9*(4/x + (9+x)/y)
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Shortcut Assignment Operators
Operator Example Equivalent
+= i+=8 i = i+8
-= f-=8.0 f = f-8.0
*= i*=8 i = i*8
/= i/=8 i = i/8
%= i%=8 i = i%8
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Increment andDecrement Operators
x++; // Same as x = x + 1;
++x; // Same as x = x + 1;
x––; // Same as x = x - 1;
––x; // Same as x = x - 1;
suffix
prefix
suffix
prefix
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Increment andDecrement Operators, cont.
int i=10; int newNum = 10*i++;
int newNum = 10*i; i = i + 1;
Equivalent to
int i=10; int newNum = 10*(++i);
i = i + 1; int newNum = 10*i;
Equivalent to
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Variables
// Compute the first arearadius = 1.0;area = radius*radius*3.14159;System.out.println("The area is “ + area + " for radius "+radius);
// Compute the second arearadius = 2.0;area = radius*radius*3.14159;System.out.println("The area is “ + area + " for radius "+radius);
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Declaring Variablesint x; // Declare x to be an // integer variable;
double radius; // Declare radius to // be a double variable;
char a; // Declare a to be a // character variable;
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if ... Else
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Displaying Text in a Message Dialog Box
you can use the showMessageDialog method in the JOptionPane class. JOptionPane is one of the many predefined classes in the Java system, which can be reused rather than “reinventing the wheel.”
RunRunSourceSource
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Actions on Eclipse
Development environment– Copy folder: Java_setup_thsoft– Install JDK– JAVA_HOME=path_to_jre– Install Eclipse (copy folder only)
Create workspace Create simple project
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Actions on Eclipse
Create, build, run welcome.java and welcomeBox.java
Rewrite demo Calcule this expression with a = b = c = 2.5;
x = y = z = 8.7
)94
(9))(5(10
5
43
y
x
xx
cbayx
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Actions on Eclipse
Problem ax + b = 0 Problem ax^2 + bx + c = 0
Input data by user. (JOptionPane)
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Action on class
Teacher – hauc2@yahoo.com– 0984380003– https://play.google.com/store/search?q=thsoft+co&c=apps
Captions Members