<%@ 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>
<%
String str = "";
for(int i=1;i<10;i++)
{
for(int j=0;j<10-i;j++)
{
str += "  ";
}
for(int x=0;x<=2*i-1;x++)
{
str += "*";
}
str += "<br>";
}
%>
<%=str %>
</body>
</html>
原文：http://www.cnblogs.com/jakeasd/p/5610401.html