Make a string uppercase in Java

/**
 * @author lautturi.com 
 * Java example: Java convert the characters in a string to uppercase
 */

import java.util.*;

public class Lautturi {
	public static void main(String args[]) {
		String str = "welcome to lauttur! java world!";
		System.out.println(str);
		str = str.toUpperCase();
		System.out.println(str);
		
		str = str.substring(5,6).toUpperCase();
		System.out.println(str);
	}
}

output:

welcome to lauttur! java world!
WELCOME TO LAUTTUR! JAVA WORLD!
M