在jsp页面输出字符"*"组成的金字塔

<%@ 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 x=1;x<=10;x++)
    {
        for(int y=1;y<=10-x;y++)
        {
            str += "&nbsp&nbsp";
        }
        for(int z=1;z<=2*x-1;z++)
        {
            str += "*";
        }
        str += "<br>";
    }
    %>
<%=str %>
</body>
</html>