public static final String getIntString(int length) {
		if (length <= 0) {
			return "";
		}
		String str = Double.toString(Math.random()).substring(2);
		int realLen = str.length();
		if (length > realLen) {
			StringBuilder sb = new StringBuilder(length).append(str);
			int remain = length - realLen;
			while (remain > 0) {
				str = Double.toString(Math.random()).substring(2);
				realLen = str.length();
				if (remain >= realLen) {
					sb.append(str);
				} else {
					sb.append(str.substring(0, remain));
				}
				remain -= realLen;
			}
			return sb.toString();
		} else {
			return str.substring(0, length);
		}
	}