1. Running Programs & IDEs Reference: COS240 Syllabus
COS240 O-O Languages AUBG, COS dept
Lecture 10b
Title:
Running Programs & IDEs
(Java)
Reference: COS240 Syllabus
6/4/2018
Assoc. Prof. Stoyan Bonev

2. Assoc. Prof. Stoyan Bonev
Lecture Contents:
Java applications classified
Processing Java source texts
How Java works
IDEs to run Java
6/4/2018
Assoc. Prof. Stoyan Bonev

3. Assoc. Prof. Stoyan Bonev
Java applications classified
Java programs may be applications or applets.
Applications are standalone programs, similar to .NET Console and Windows applications.
Applets are similar to applications, but they do not run as standalone programs.
- Instead, applets adhere to a set of conventions that lets them run within a Java-compatible browser (client-side).
- You can only run an applet from an HTML page.
6/4/2018
Assoc. Prof. Stoyan Bonev

4. Java, C#, C++ - High Level PL
In order to run /to execute/, any program written in HLL should be transformed to executable form
Three ways to convert source code into executable form:
Compiler – generate object code
Interpreter – interpret the source code
Compiler of semi-interpreting type
6/4/2018
Assoc. Prof. Stoyan Bonev

5. Assoc. Prof. Stoyan Bonev
data
Object program
Executing computer
Results
Source program
compiler
Run time
Compile time
6/4/2018
Assoc. Prof. Stoyan Bonev

6. Assoc. Prof. Stoyan Bonev
Data
Source program
Interpreter
Results
Compile time
Run time
6/4/2018
Assoc. Prof. Stoyan Bonev

7. Assoc. Prof. Stoyan Bonev
data
Object program in IL form
Interpreter
Results
Source program
compiler
Compile1 time
Compile2 time
Run time
6/4/2018
Assoc. Prof. Stoyan Bonev

8. Processing HLL programs
Java is compiled to intermediate form – bytecode. Bytecode processed by interpreter named JVM.
C# and C++ (managed code) are compiled to intermediate form – MSIL code. MSIL code processed by interpreter named CLR.
C++ (native, unmanaged code) is directly compiled to executable native machine code. No intermediate code, no need of interpreter.
6/4/2018
Assoc. Prof. Stoyan Bonev

9. Assoc. Prof. Stoyan Bonev
How Java works
6/4/2018
Assoc. Prof. Stoyan Bonev

10. Assoc. Prof. Stoyan Bonev
How Java Works
Java's platform independence is achieved by the use of the Java Virtual Machine (JVM).
A Java program consists of one or more files with a .java extension
these are just text (i.e. source) files.
When a Java program is compiled, the .java files are fed to the compiler which produces a .class file for each .java file.
The .class file contains Java bytecode.
Java bytecode is like machine language, but it is intended for the Java Virtual Machine, not a specific processor.
6/4/2018
Assoc. Prof. Stoyan Bonev

12. Executing a Java program

13. JVM emulation run on a physical machine

14. JVM handles translations

15. Java Popularity
Pure Java includes 3 software facilities:
JRE
JVM
JDK

16. The Java Runtime Environment (JRE) provides
the libraries,
the Java Virtual Machine, and
other components to run applets and applications written in Java.

17. JVM - Overview
Java Virtual Machine is a program which executes certain other programs, namely those containing Java bytecode instructions.
JVM is distributed along with Java Class Library, a set of standard class libraries (in Java bytecode) that implement the Java application programming interface (API). These libraries, bundled together with the JVM, form the Java Runtime Environment (JRE).
JVMs are available for many hardware and software platforms. The use of the same bytecode for all JVMs on all platforms allows Java to be described as a write once, run anywhere programming language, versus write once, compile anywhere, which describes cross-platform compiled languages.
Oracle Corporation, the owner of the Java trademark, produces the most widely used JVM, named HotSpot, that is written in the C++ programming language.

18. JVM JVM architecture. Source code is compiled to Java bytecode, which
is verified, interpreted or
JIT-compiled for the
native architecture.
The Java APIs and JVM
together make up the
Java Runtime Environment
(JRE).

19. JDK contents
The JDK has
a collection
of programming tools,
including:

20. JDK contents
java – the loader for Java applications. This tool is an interpreter and can interpret the class files generated by the javac compiler. Now a single launcher is used for both development and deployment. The old deployment launcher, jre, no longer comes with Sun JDK, and instead it has been replaced by this new java loader.
javac – the Java compiler, which converts source code into Java bytecode
javadoc – the documentation generator, which automatically generates documentation from source code comments
jar – the archiver, which packages related class libraries into a single JAR file. This tool also helps manage JAR files.

21. A Simple Java Program Listing 1.1
//This program prints message “Welcome, Java!“
// braces in new-line style
public class Welcome {
public static void main(String[] args)
System.out.println("Welcome to Java!"); }
Source: Longman dictionary 1987

22. A Simple Java Program Listing 1.1
//This program prints message “Welcome, Java!“
// braces in end-line style (recommended)
public class Welcome {
public static void main(String[] args) {
System.out.println("Welcome to Java!"); }
Source: Longman dictionary 1987

23. Creating, Compiling, and Running Java Programs

24. Compiling Java Source Code
You can port a source program to any machine with appropriate compilers. The source program must be recompiled, however, because the object program can only run on a specific machine. Nowadays computers are networked to work together. Java was designed to run object programs on any platform. With Java, you write the program once, and compile the source program into a special type of object code, known as bytecode. The bytecode can then run on any computer with a Java Virtual Machine, as shown below. Java Virtual Machine is a software that interprets Java bytecode.

25. Approaches to run Java How to Compile/Run Java Programs Java IDEs
javac, java
Java IDEs
TextPad, jGRASP, BlueJ, NetBeans, Eclipse
Java Development Tools
javadoc, jar, jdb
Java Programming: From Problem Analysis to Program Design, 3e

26. Creating, Compiling & Running Java
From the Command Window
From within IDE
6/4/2018
Source: Longman dictionary 1987

27. Creating, Compiling and Running Java from Command Line Window
First: to open a Command Window
Click Start, All Programs, Accessories, Command Prompt
Second: to create a separate directory/folder on C: drive or Q: drive where to save .java and .class files
md COS240Progs
cd COS240Progs
Third: to Set path to JDK bin directory
Already done by OCC
Fourth: to create and save Java source file
Notepad/Write Welcome.java
Fifth: to Compile
javac Welcome.java
Sixth: to Run
java Welcome

28. Creating and Editing Using editors like Notepad, WordPad, etc
To use NotePad, type
notepad Welcome.java
from the DOS prompt.
To use WordPad, type
write Welcome.java
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29. Compiling, and Running Java Programs
In order to compile your Java program, you should type
javac Welcome.java
In order to run your compiled to bytecode Java program, you should type
java Welcome
6/4/2018

30. Compiling, and Running Java Programs
public class Welcome {
public static void main(String args[]) {
int i=1;
while (i<5) {
System.out.println("Greeting to Blagoevgrad!");
i++;
} // end of while loop
} // end of method main
} // end of Welcome class
6/4/2018

31. Compiling and Running Java from IDEs
Java IDEs:
TextPad
jGRASP
BlueJ
NetBeans – Open source by Sun
Eclipse – Open source by IBM
6/4/2018
Source: Longman dictionary 1987

32. Compiling and Running Java from TextPad.
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Source: Longman dictionary 1987

33. Compiling and Running Java from TextPad
Edit the .java file
The edited file should be saved before the coming commands to take effect.
Subjects of interest:
Select tools, click run (user is expected to type command and parameters)
Command:javac Parameter:Welcome.java
Command:java Parameter:Welcome
Select view, click tool output
6/4/2018

34. Compiling and Running Java from TextPad
public class COS240 {
public static void main(String args[]) {
int i=1;
for (i=1; i<=5; i++)
System.out.println("Greeting from COS dept"); }
6/4/2018

35. Compiling and Running Java from jGRASP
6/4/2018
Source: Longman dictionary 1987

36. Compiling and Running Java from jGRASP
Subjects of interest:
Select Build, Click Compile
Select Build, Click Run Or
Select Build, Click Run as Applet
Select Build, Click Run as Application
CheckBox: run in MS-DOS window
6/4/2018

37. Compiling and Running Java from jGRASP
import java.util.Scanner;
public class COS240Proba {
public static void main(String args[]) {
Scanner cin = new Scanner(System.in);
int pom = cin.nextInt();
float pom2 = cin.nextFloat();
double pom3 = cin.nextDouble();
System.out.println(" " + pom + " " + pom2 + " " + pom3); }
6/4/2018

38. Compiling and Running Java from BlueJ
6/4/2018
Source: Longman dictionary 1987

39. Compiling and Running Java from BlueJ
6/4/2018
Source: Longman dictionary 1987

40. Compiling and Running Java from NetBeans
6/4/2018
Source: Longman dictionary 1987

41. Compiling and Running Java from NetBeans
Subjects of interest:
The concept of a project
The user is expected:
To choose project (Categories: Java, Projects: Java application)
To name the project and to locate the project
To create Main class and to set as Main project
To type the Java source text
To select Run, click Run Main Project (F6) Or
To select Run, click Build Main Project(F11), click Run Main Project (F6)
To select Run, click Clean and Build Main Project(Shift+F11), click Run Main Project (F6)
6/4/2018
Source: Longman dictionary 1987

42. Compiling and Running Java from Eclipse
6/4/2018
Source: Longman dictionary 1987

43. Compiling and Running Java from Eclipse
Subjects of interest:
The concept of a project
Compilation activated when File_save activity take place
List of steps to follow:
6/4/2018
Source: Longman dictionary 1987

44. Compiling and Running Java from Eclipse
Open the Java perspective:
In main menu select Window > Open Perspective > Java
Create a Java project
In main toolbar Click New Java Project btn, Enter HelloWorld for name, click Finish
Create your Helloworld class
In main toolbar Click New Java class btn, select xx\src as a source folder, enter HelloWorld for class name, click check box to create the main() method, click Finish
Add a println statement
Type stmts, then save changes, the class will automatically compile upon saving
Run your java application
Right click on your class in the Package Explorer, and then select Run As>Java application
6/4/2018
Source: Longman dictionary 1987

45. Eclipse Downloads: Tutorials: http://www.eclipse.org/downloads/
6/4/2018

46. Java Development Tools
Brief overview on Java Development Tools: (Detailed discussion in lecture 29)
java
javac
javadoc
jar
jdb
6/4/2018
Source: Longman dictionary 1987

47. Running java Description Common Options Synopsis
java [interpreter options] classname [program arguments]
java [interpreter options] -jar jarfile [program arguments]
Description
Common Options
6/4/2018
Source: Longman dictionary 1987

48. Running javac Description Common Options Synopsis
javac [options] files
Description
Common Options
6/4/2018
Source: Longman dictionary 1987

49. Running javadoc Description Common Options Synopsis
javadoc [options] @list package… sourcefiles…
Description
Common Options
6/4/2018
Source: Longman dictionary 1987

50. Running jar Description Common Options Synopsis
jar c|t|u|x [jarfile] [manifest] [-C directory] [input files]
jar I [jarfile]
Description
Common Options
6/4/2018
Source: Longman dictionary 1987

51. Running jdb Description Common Options Synopsis
jdb [options] class [program options]
Description
Common Options
6/4/2018
Source: Longman dictionary 1987

52. Assoc. Prof. Stoyan Bonev
Practical session
Task: write a program to input two integral values and to compute and display the result of their addition, subtraction, multiplication and division
Language: Java
IDE: Eclipse
6/4/2018
Assoc. Prof. Stoyan Bonev

53. Assoc. Prof. Stoyan Bonev
Practical session
Task: write a program to input two integral values and to compute and display the result of their addition, subtraction, multiplication and division
Language: Java
IDE: NetBeans
6/4/2018
Assoc. Prof. Stoyan Bonev

54. Assoc. Prof. Stoyan Bonev
Practical session
Task: write a program to input two integral values and to compute and display the result of their addition, subtraction, multiplication and division
Language: Java
IDE: jGRASP
6/4/2018
Assoc. Prof. Stoyan Bonev

55. Assoc. Prof. Stoyan Bonev
Practical session
Problem:
To accumulate sum of stream of input integers terminated by sentinel value
Language: Java
IDE: Eclipse
6/4/2018
Assoc. Prof. Stoyan Bonev

56. Assoc. Prof. Stoyan Bonev
Practical session
Problem:
To accumulate sum of stream of input integers terminated by sentinel value
Language: Java
IDE: NetBeans
6/4/2018
Assoc. Prof. Stoyan Bonev

57. Assoc. Prof. Stoyan Bonev
Practical session
Problem:
To accumulate sum of stream of input integers terminated by sentinel value
Language: Java
IDE: jGRASP
6/4/2018
Assoc. Prof. Stoyan Bonev

58. Thank You
for
Your attention!