Java Source Code

Binary Search

2010-03-30T03:39:00.000-07:00

public class Search
{
/**
The method searches the key in the array passed to it.If the key is
found the position of the key is returned otherwise -1 is returned.
*/
public static int binarySearch(double[] data,double key)
{
int position=-1;
int start=0;
int end=data.length-1;
int middle;
do
{
middle=(start+end)/2;

if(data[middle]==key)
{
//data found
position=middle;
}
else if(data[middle]<key)
{
start=middle+1;
}
else
{
end=middle-1;
}

}
while(start<=end && position==-1);

return position;
}

public static void main(String args[])
{
//calling binarySearch method
//data must be sorted by ascending order for this method to work
double sortedData[]={10,15.5,20,25,25.75,50,77,500,600.99};
double key=50;

int position=Search.binarySearch(sortedData,key);

if(position>=0)
{
System.out.println(key+" is found at position "+position);
}
else
{
System.out.println(key+" is not found in the array");
}

}
}

You can download the code here.

Linear Search

2010-03-30T03:16:00.000-07:00

public class Search
{
/**
The method searches the key in the array passed to it.If the key is
found the position of the key is returned otherwise -1 is returned.
*/

public static int linearSearch(double[] data,double key)
{
int position=-1;

for(int i=0;i<data.length;i++)
{
if(data[i]==key)
{
position=i;
break;
}
}

return position;
}

public static void main(String args[])
{
//calling linerSearch method
double unsortedData[]={5,13,18,4,1,27,50,63.35,100,59};
key=100;
position=Search.linearSearch(unsortedData,key);

if(position>=0)
{
System.out.println(key+" is found at position "+position);
}
else
{
System.out.println(key+" is not found in the array");
}
}
}

You can download this code here.

Calculator Applet

2009-08-15T09:59:00.001-07:00

A simple standard calculator developed in Java Applet. By this calculator you can add, subtract, multiply and divide numbers online. Other online operations of the calculator includes square root, square, cubic root, cube etc. AC and DEL button also exist for clear and delete operations.

Downloads:

Jar File : JCalculatorApplet.jar

NetBeans Project: JCalculatorApplet.zip

Individual Java Source File: JCalculatorApplet.java

JFreeHandDrawing

2009-06-25T21:01:00.000-07:00

JFreeHandDrawing is a Java program which is used for freehand drawing with the mouse.

Features include:

- Colors: You can draw in different colors. The supported colors are Black, Blue, Cyan, Gray, Green, Magenta, Orange, Pink, Red, White and Yellow.
- Pointer Location: The program always shows the mouse pointer location in the title bar. The title is changed dynamically for the mouse movement.

This is not a serous program – it’s a fun. You can use it for education purpose only to learn about how to draw in Java.

Downloads:

Executable Jar: JFreeHandDrawing.jar

NetBeans Project: JFreeHandDrawing.zip

Individual Source File: JFreeHandDrawing.java

JStopWatch

2009-05-29T08:08:00.000-07:00

JStopWatch is a simple program developed in Java programming language which has the functionality of a stop watch like start, stop, pause, resume etc. JStopWatch can be used to know the elapsed time for a particular operaion.

Two Java classes are developed for this program. JStopWatch is created for the stop watch functionality. JStopWatch has inherited the Thread class. JStopWatch has three private attributes hour, minute, second. This program continuously increase the value of second after every 1000 millisecond. In the same way, it increases the value of minute, and hour after every 60 seconds and 60 minutes respectively.

Thread class method start, suspend, resume and stop methods are used for start, pause, resume and stop the watch.

A UI class (JStopWatchUI) has been defined separately for showing the output of JStopWatch. The UI class has an inner class for updating the UI continuously based on the value of JStopWatch.

Followings are some of the screen shots:

Figure: JStopWatch before the start

Figure: JStopWatch after the start

Figure: JStopWatch after the pause

Figure: JStopWatch after the resume

Figure: JStopWatch after the stop

Downloads:

Executable Jar File : JStopWatch.jar

NetBeans Projects: JStopWatch.zip

Individual Java Source Files: JStopWatch.java , JStopWatchUI.java

JExceptionReporter

2009-05-19T20:46:00.001-07:00

JExceptionReporter shows short or detail exception report in graphical user interface. Generally we show the Java exception stack trace in console by calling printStackTrace method. If you want to show the stack trace in graphical mode, you can use the JExceptionReporter.

Just call the showExceptionReport method of JExceptionReporter giving the Exception object in your catch block like below:

try
{
double number1=Double.parseDouble(txtFirstNumber.getText());
double number2=Double.parseDouble(txtSecondNumber.getText());
txtResult.setText(String.valueOf(number1/number2));
}
catch(NumberFormatException nfe)
{
JExceptionReporter.showExceptionReport(nfe);
}
catch(ArithmeticException ae)
{
JExceptionReporter.showExceptionReport(ae);
}

Then you will see the following output if any exception occurs in runtime.

Initially it will show the short message (what exception occurred) only but it will show the details stack trace if you click ‘Show Details’ button. Again you can shorten it by clicking the ‘Hide Details’ button.

Downloads:

Executable Jar File : JExceptionReporter.jar

NetBeans Project : JExceptionReporter.zip

Individual Java Source File : JExceptionReporter.java , TestJExceptionReporter.java

JImageViewer

2009-05-17T03:47:00.000-07:00

A simple image viewing application developed in Java. The application shows all the supported images (jpg, gif and png) of a selected folder in thumbnail view. Full image view can be seen if a thumbnail is double clicked. See the screen shots below:

Figure: Folder Open Dialog

Figure: Thumbnail Image View of JImageViewer

Figure: Full Image View of JImageViewer

Downloads:

Executable Jar File : JImageViewer.jar

NetBeans Project: JImageViewer.zip

Individual Java Source Files: ThumbnailImageViewer.java and FullImageViewer.java

JDigitalClock

2009-05-17T03:37:00.001-07:00

A digital clock that shows system time in hour, minute and second with am/pm.

Downloads:

Executable Jar File : JDigitalClock.jar

NetBeans Project: JDigitalClock.zip

Individual Java Source Files: JDigitalClock.java and JDigitalClockTest.java

JCalculator

2009-05-17T03:15:00.000-07:00

A simple standard calculator developed in Java programming language. By this calculator you can add, subtract, multiply and divide numbers. Other operations of the calculator includes square root, square, cubic root, cube etc. AC and DEL button also exist for clear and delete operations.

Downloads:

Executable Jar File : JCalculator.jar

NetBeans Project: JCalculator.zip

Individual Java Source File: JCalculator.java

JNotePad

2009-05-16T01:25:00.000-07:00

You can develop a notepad in Java very easily. In this blog post you will get the source code for developing a simple notepad program in Java. The executable jar file, NetBeans project with full source code are available for download.

Some screen shots of the JNotePad is as follows:

Figure: Options of File menu

Figure: Options of Edit menu

Figure: Options of Format menu

Some features of JNotePad programs:

1. Open a text file from any folder

2. Cut, Copy and Paste support for editing the file
3. Save a file in user selected folder (Both Sava and Save As operations)

4. Print the file
5. Set font from a font dialog. Font can be chosen from the list of available system fonts. Font size and the font style (Plain, Bold and/or Italic) can be set.
6. Line wrap format option
7. Select the look and feel from the list of installed look and feels.
8. Scrolling option for the large file.

Downloads:

Executable jar file: JNotePad.jar

NetBeans Project: of JNotePad.zip

Individual Java Source Files: JNotePad.java and JFontChooser.java