package cn.edu.bjut.utils;

public class StringUtils {
	public final static char SEPARATOR = '/';
	
	public static String capitalize(String str) {
		if (str == null) {
			return null; 
		} 
		
		if (str.length() == 1) {
			return str.toUpperCase(); 
		}
		
		return str.substring(0, 1).toUpperCase() + str.substring(1).toLowerCase(); 
	}
	
	public static boolean isIpc(String str) {
		char section = str.charAt(0); 
		if (section < 'A' || section > 'H') {
			return false; 
		}
		
		int mainClass = Integer.parseInt(str.substring(1, 3)); 
		if (mainClass < 1 || mainClass > 99) {
			return false; 
		}
		
		char subclass = str.charAt(3); 
		if (subclass < 'A' || subclass > 'Z') {
			return false; 
		}
		
		int pos = str.indexOf(SEPARATOR); 
		int mainGroup = Integer.parseInt(str.substring(4, pos).trim()); 
		if (mainGroup < 1 || mainGroup > 9999) {
			return false; 
		}
		
		int subgroup = Integer.parseInt(str.substring(pos + 1)); 
		if (subgroup < 0 || subgroup > 99999) {
			return false; 
		}
		
		return true; 
	}
	
	public static void main(String[] args) {
		String str = "heLLO"; 
		System.out.println(StringUtils.capitalize(str)); 
		
		String symbol = "G06F 17/30"; 
		System.out.println(StringUtils.isIpc(symbol)); 
	}
}