randomstr.java

	private static String nextRngString() {
		for (int idx = 0; idx < buf.length; ++idx) 
			buf[idx] = symbols[random.nextInt(symbols.length)];
		return new String(buf);
	}
	
	
	/* *****************************
	 * **** Private  constants *****
	 ***************************** */
	
	static {
		StringBuilder tmp = new StringBuilder();
		for (char ch = '0'; ch <= '9'; ++ch)
			tmp.append(ch);
		for (char ch = 'a'; ch <= 'z'; ++ch)
			tmp.append(ch);
		symbols = tmp.toString().toCharArray();
	}
	
	private static final char[] symbols;
	private static final Random random = new Random();
	private static final char[] buf = new char[____NUMERO_DE_CARACTERES____];