awt lower to upper

//Import Statements

import java.awt.*;

import java.awt.event.*;

//Class method

class ChangeCase extends Frame implements ActionListener

{

    //Variable declaration

    Checkbox ch1,ch2,ch3,ch4,ch5;

    CheckboxGroup chg;

    Button bu;

    TextArea tax;

    public ChangeCase(String title)//Main method

    {

    super(title);

    chg=new CheckboxGroup();//Object creation

    ch1=new Checkbox("SentenceCase",chg,false);

    ch2=new Checkbox("lowercase",chg,false);

    ch3=new Checkbox("UPPERCASE",chg,false);

    ch4=new Checkbox("TitleCase",chg,false);

    ch5=new Checkbox("tOGGLEcASE",chg,false);

    bu=new Button("Apply");

    tax=new TextArea();

    setLayout(new GridLayout(7,1));

    add(ch1);

    add(ch2);

    add(ch3);

    add(ch4);

    add(ch5);

    add(bu);

    add(tax);

    bu.addActionListener(this);

//  addWindowListener(new Mywindow());

    setSize(400,400);

    setVisible(true);

    }

    // © http://students3k.com – Karhtikh venkat

    public void actionPerformed(ActionEvent e)

    {

 

        if(e.getSource()==bu)//Decision making statement

        {

                int i;

                StringBuffer str=new StringBuffer(ta.getText());

                String s;

                if(ch1.getState()==true)

                {

                str.insert(0,Character.toUpperCase(str.charAt(0)));

                str.deleteCharAt(1);

                for(i=0;i<str.length();i++)//For statement

                    {

                    if(str.charAt(i)=='.')

                    {

                    str.insert(i+2,Character.toUpperCase(str.charAt(i+2)));

                    str.deleteCharAt(i+3);

                    }

                }

                tax.setText(new String(str));

                }

                else if(ch2.getState()==true)

                {

                s=tax.getText();

                s=s.toLowerCase();

                tax.setText(s);

                }

                else if(ch3.getState()==true)

                {

                s=tax.getText();

                s=s.toUpperCase();

                tax.setText(s);

                }

                else if(ch4.getState()==true)

                {

                s=tax.getText();

                s=s.toLowerCase();

                str=new StringBuffer(s);

        // © http://students3k.com – Karhtikh venkat

    str.insert(0,Character.toUpperCase(str.charAt(0)));

                str.deleteCharAt(1);

                for(i=0;i<str.length();i++)

                {

                if(Character.isSpace(str.charAt(i))==true)

                    {

                    str.insert(i+1,Character.toUpperCase(str.charAt(i+1)));

                    str.deleteCharAt(i+2);

                    }

                }

                tax.setText(new String(str));

                }

                else

                {

                s=tax.getText();

                s=s.toUpperCase();

                str=new StringBuffer(s);

                str.insert(0,Character.toLowerCase(str.charAt(0)));

                str.deleteCharAt(1);

                for(i=0;i<str.length();i++)

                {

                if(Character.isSpace(str.charAt(i))==true)

                    {

                    str.insert(i+1,Character.toLowerCase(str.charAt(i+1)));

                    str.deleteCharAt(i+2);

                    }

                }

                tax.setText(new String(str));

                }

 

        }

        // © http://students3k.com – Karhtikh venkat

    }

    public static void main(String a[])

    {

    ChangeCase n=new ChangeCase("ChangeCase");

    }

}