如何判断两位小数

public static boolean isDecimal(String str){
	  return Pattern.compile("([1-9]+[0-9]*|0)(\\.[0-9]{1,2})?").matcher(str).matches();
		  //return Pattern.compile("([1-9]+[0-9]*|0)(\\.[\\d]+)?").matcher(str).matches();
	}
	
	public static void main(String[] args) {
		  /*System.out.println("12.333:"+isDecimal("12.333"));
		  System.out.println("123:"+isDecimal("123"));
		  System.out.println("0.123:"+isDecimal("0.123"));
		  System.out.println(".123:"+isDecimal(".123"));
		  System.out.println("1.23:"+isDecimal("1.23"));
		  System.out.println("123.:"+isDecimal("123."));
		  System.out.println("00.123:"+isDecimal("00.123"));
		  System.out.println("123.0:"+isDecimal("123.0"));
		  System.out.println("123.00:"+isDecimal("123.00"));
		  System.out.println("0123:"+isDecimal("0123"));
		  System.out.println("-123.33:" + isDecimal("-123.33"));*/
		  BigDecimal bigDecimal = new BigDecimal("20.3");
		  System.out.println(bigDecimal.multiply(new BigDecimal(100)).intValue());
		  //System.out.println(Integer.parseInt(String.valueOf(bigDecimal.multiply(new BigDecimal(100)))));
	}