The server encountered an internal

HTTP Status 500 - --------------------------------------------------------------------------------type Exception reportmessage description The server encountered an internal error () that prevented it from fulfilling this request.exception org.apache.jasper.JasperException: Exception in JSP: /ch01/detailed.jsp:63: <%
4:   List typeinfoList =(List)request.getAttribute("typeinfoList");   
5:   List productList =(List)request.getAttribute("productList"); 
6:   Product product=(Product)productList.get(1);
7:   Double pice=  product.getMarketPrice()-product.getSalePrice();
8:   session.setAttribute("product",product);
9:  %>
Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:506)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:395)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
com.zhoujun.servlet.DetailedServlet.doPost(DetailedServlet.java:70)
com.zhoujun.servlet.DetailedServlet.doGet(DetailedServlet.java:24)
javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
com.zhoujun.filter.MyFilter.doFilter(MyFilter.java:22)
root cause java.lang.IndexOutOfBoundsException: Index: 1, Size: 1
java.util.ArrayList.RangeCheck(Unknown Source)
java.util.ArrayList.get(Unknown Source)
org.apache.jsp.ch01.detailed_jsp._jspService(detailed_jsp.java:51)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:334)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
com.zhoujun.servlet.DetailedServlet.doPost(DetailedServlet.java:70)
com.zhoujun.servlet.DetailedServlet.doGet(DetailedServlet.java:24)
javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
com.zhoujun.filter.MyFilter.doFilter(MyFilter.java:22)
note The full stack trace of the root cause is available in the Apache Tomcat/5.5.20 logs.
找不到错哪里了？ 很郁闷 强烈求助！
--------------------------------------------------------------------------------Apache Tomcat/5.5.20