主页面t2.jsp
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title>include动作--不带参数</title> </head> <body> <div style="text-align:center"> <h1>请输入一个正数,单击按钮求这个数的平方根。</h1> <hr> <jsp:include page="t2_ok.jsp" /> </div> </body> </html>
辅页面t2_ok.jsp
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title>Insert title here</title> </head> <body> <% double num = 0; String str=request.getParameter("num"); try{ if(str!=null){ num = Double.parseDouble(str); }else{ out.println("【提示:】请输入数据,谢谢!"); } } catch(Exception e){ out.println("只能输入数字") ; } %> <p>请输入一个数字,谢谢!</p> <form action="#" method="post" name="form"> <input type="text" name="num"><br><br> <input type="submit" name="submit" value="开始计算"> </form> <p><%=num%>的平方根是:<%=Math.sqrt(num)%></p> </body> </html>