Hi Friend,

Try the following code:

import java.util.*;

class CaseConverter{
public static void main(String[] args) {
Scanner input=new Scanner(System.in);
System.out.print("Enter string: ");
String str=input.nextLine();
StringBuffer sb=new StringBuffer();
char ch[]=str.toCharArray();
for(int i=0;i<ch.length;i++){
if(ch[i]==' '){
sb.append(" ");
}
if(Character.isLowerCase(ch[i])){
char cha=Character.toUpperCase(ch[i]);
sb.append(Character.toString(cha));
}
else if(Character.isUpperCase(ch[i])) {
char cha=Character.toLowerCase(ch[i]);
sb.append(Character.toString(cha));
}
}
System.out.println(sb.toString()+" ");
}
}

Thanks