computer.jsp

黑魔方JSP基础教程源代码(耿祥义编著)是这里有课件和jsp源代码

<form action "" method=post name=form>
<input type="text" name="txt1">
<br>
<input type="submit" value="ok" name=submit>
</form>
<%
	String a=request.getParameter("txt1");
	if(a==null)
	{
		a="1";
	}
	try{
		double number=Integer.parseInt(a);
		out.print("<br>"+Math.sqrt(number));
	}
	catch(NumberFormatException e)
	{out.print("<br>"+"请输入数字字符");}
%>