cw2c.java.org

samll awt programs for the beginner.

/**
* Author: Jing Han
* Date; 12/11/03
*Module: G6DICp
* Title: ICP Coursework 2
* SCSiT Username: jxh23m
*/




import java.io.*;
import java.awt.*;
import java.util.*;


class MainWindow extends Frame
{
    
    String title;
    
    public MainWindow()
    {
     setLayout(null);
     setSize(400,400);
     setBackground(Color.gray);
     setTitle("Pie Chart");
     doStuff();
     
     } //end of mainwindow   

    
    public void doStuff()
    {
            //prompt for filename
        System.out.print("Enter data file:"+"  ");
        String filename=TButils.readln();
        
        //declare varialbe title and instantiate vector
        title = "";
        Vector data=new Vector();
        double sum=0;
        Integer myInteger;
        double datavalue; 
        
        
        //instantiate RandomAeccessFile. myData file is opened for reading
        try 
        {
            RandomAccessFile inFile=new RandomAccessFile(filename,"r");
            String line; //a string to contain the line read
            int lineNo=0;//initialise the line number of file
            
            // use the readLine method to read a line into the string line 
        //until the end of the file
            while((line=inFile.readLine())!=null) 
            {
               
                if( lineNo == 0 )
                {
                    title=line;
                 }// store the first line into title
                 
                 else
                 {
                        myInteger=Integer.valueOf(line);    //convert string to Integer
                        datavalue=myInteger.doubleValue();    //get the int value of data
                        sum=sum+datavalue;        //do sum calculation
                    	data.addElement(myInteger); //cast Integer to vector object
                 }// store the rest of file into vector data
          
            
                lineNo++; //track line number to seperate the title input from vector input  

       
            }//end of while loop 
         }// end of try 
         catch (IOException e)
         {
            System.out.println("An i/o error has occured ["+e+"]");
         }// end of catch exception

      
         
         System.out.println("Title:"+"  "+title);// print out title
     	 System.out.println("     "+"Data"+"     "+"Angle(degree)");//print out line of text

         
         // instatiate new vector angle and delacare new variables
        Integer tmpValue;     		  // store temporary int variable
 	double value;           		  // primitive int value
	double angleDouble;      		  // primitive anlge int value
	int angleInt;
	Double myD;
	
	Vector angle=new Vector();	 // vector to contain angle 
	
         for(int n=0;n<data.size();n++)
         {
            
                  tmpValue=(Integer)data.elementAt(n);	//cast object from vector to Integer
                  value=tmpValue.doubleValue();		//convert Integer to int
                  angleDouble=Math.round(360*value/sum);	//caculate the angle
		  myD=new Double(angleDouble);
		  angleInt=myD.intValue();
		 
				  
                 angle.addElement(new Integer(angleInt));/*convert int angle to Integer
							  cast Integer to vector object*/
                 
         
         }// end of for loop 
     
         //print out data in two vectors
     for(int n=0;n<angle.size();n++)
     {
        System.out.println("      "+data.elementAt(n)+"       "+angle.elementAt(n));
     }//end of for loop 
     	
 	   	
    }
    
    public void paint(Graphics g)
    {
        super.paint(g);
        
        // draw a circle

        // draw a yellow circle
        g.setColor(Color.yellow);    
        g.drawOval(100,60,100,100); // NB draw two concentric circles (to make it thick)
        g.drawOval(101,61,98,98);
            
        // write the message in white SansSerif bold 16
        g.setColor(Color.white);            
        g.setFont(new Font("SansSerif", Font.BOLD, 16));
        g.drawString(title,105,45);
    }//end of paint
}//end of mainwindow class


class cw2c
{
    public static void main(String args[])
    {
     MainWindow myWindow=new MainWindow();
     myWindow.show();
    }
}