how to check given string is long or not in java code example

Example: check if string is decimal java

Scanner in = new Scanner(System.in);
		
		String ip1 = in.nextLine();
		
		if( ip1.matches("^\\d+\\.\\d+") ) 
			System.out.println(ip1+"----is a decimal number");
		else
			System.out.println(ip1+"----is a not decimal number");