String index out of range: -2 code example

Example: String index out of range: 7

package com.yawintutor;

public class StringSubstringCharAt {
	public static void main(String[] args) {
		String str = "Bangalore";
		String str2;

		str2 = str.substring(3, 8);

		System.out.println("Given  String : " + str);
		System.out.println("Output String : " + str2);
	}
}