1. Java is an object-oriented, distributed, interpreted, robust, secure, architecture-neutral, and portable programming language. 2. It is interpreted, meaning code is compiled into bytecode that runs on a Java Virtual Machine (JVM) on any system with a JVM. 3. Java incorporates features for object-orientation, networking, security, exception handling and more, making it a powerful yet flexible language for application development.

1. 1. Java is Object-Oriented
• Object-oriented programming provides great flexibility, modularity, clarity, and
reusability through encapsulation, inheritance, and polymorphism.
2. Java Is Distributed
• Distributed computing involves several computers working together on a network.
• Java is designed to make distributed computing easy as networking capability is
inherently integrated into Java.
• Thus, writing network programs is like sending and receiving data to and from a
file.
CHARACTERISTICS OF JAVA

2. 3. Java Is Interpreted
• You need an interpreter to run Java programs.
• The programs are compiled into the Java Virtual Machine code called bytecode.
• The bytecode is machine-independent and can run on any machine that has a Java
interpreter, which is part of the Java Virtual Machine (JVM).
4. Java Is Robust
• Java compilers can detect many problems that would first show up at execution
time in other languages.
• Java has a runtime exception-handling feature to provide programming support
for robustness.
CHARACTERISTICS OF JAVA

3. 5. Java Is Secure
• Java implements several security mechanisms to protect your system against
harm caused by stray programs.
6. Java Is Architecture-Neutral
• Write once, run anywhere. With a Java Virtual Machine (JVM), you can write one
program that will run on any platform.
7. Java Is Portable
• They can be run on any platform without being recompiled.
CHARACTERISTICS OF JAVA

4.  Set path to JDK bin directory
set path=c:Program Filesjavajdk1.6.0bin
 Set classpath to include the current directory
set classpath=.
 Compile
javac Welcome.java
 Run
java Welcome
COMPILING AND RUNNING JAVA FROM THE CMD

5.  Right click My Computer.
 Choose Properties from the context menu.
 Click the Advanced system settings link.
 Go to Advanced tab. Click Environment Variables.
 In the section System Variables, find the PATH environment variable and
select it. Click Edit.
 If the PATH environment variable does not exist, click New.
 In the Edit System Variable (or New System Variable) window, specify
the value of the PATH environment variable.
 Click OK. Close all remaining windows by clicking OK.
SETTING PATH AND CLASSPATH DIRECTLY IN WINDOWS 7

6. After installation, the JDK directory will have the structure shown below.
C:Javajdk1.7.0bin //contains both the compiler and the launcher.
 The PATH environmental variable contains the path of the executables (javac.exe,
java.exe, javadoc.exe, and so on)
 The CLASSPATH variable is one way to tell applications, including the JDK tools, where
to look for user classes.
 After setting the PATH variable, we can access these executables (compiler, launcher
etc) from any directory without having to type the full path of the command. For e.g.
javac Example.java- If the PATH is set, then we use following in CMD
C:Javajdk1.7.0binjavac Example.java - Otherwise
The following is an example of a PATH environment variable:
C:Javajdk1.7.0bin;C:WindowsSystem32;C:Windows;C:WindowsSystem32Wbem
PATH and CLASSPATH

7. 1. System.out.println(“Hello World”); – outputs the string
“Hello World” followed by a new line on the screen.
2. System.out.print(“Hello World”); - outputs the string “Hello
World” on the screen. This string is not followed by a new line.
3. Some Escape Sequence –
• n – stands for new line character
• t – stands for tab character
PRINTING ON THE SCREEN

8. //This program prints Welcome to Java!
public class Welcome {
public static void main(String[] args) {
System.out.println("Welcome to Java!");
}
}
A SIMPLE JAVA PROGRAM

9. //This program prints Welcome to Java!
public class Welcome {
public static void main(String[] args) {
System.out.println("Welcome to Java!");
}
}
PROGRAM EXECUTION – STEP I
Enter main method.
The main method provides the control of program flow. The Java interpreter
executes the application by invoking the main method.

10. //This program prints Welcome to Java!
public class Welcome {
public static void main(String[] args) {
System.out.println("Welcome to Java!");
}
}
PROGRAM EXECUTION – STEP II
Execute Statement 1

11.  Java Standard Edition (J2SE)
J2SE can be used to develop client-side standalone
applications or applets.
 Java Enterprise Edition (J2EE)
J2EE can be used to develop server-side applications such as
Java servlets and Java ServerPages.
 Java Micro Edition (J2ME)
J2ME can be used to develop applications for mobile devices
such as cell phones.
 Popular Java IDEs
 NetBeans Open Source by Sun
 Eclipse Open Source by IBM
JDK Editions & IDEs