at org.apache.jsp.result_jsp._jspService(result_jsp.java:66)

Stacktrace:
\x05org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:521)
\x05org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:430)
\x05org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
\x05org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
\x05javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
root cause
java.lang.NullPointerException
\x05org.apache.jsp.result_jsp._jspService(result_jsp.java:66)
\x05org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
\x05javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
\x05org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:388)
\x05org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
\x05org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
\x05javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
note The full stack trace of the root cause is available in the
Apache Tomcat/6.0.35 logs.
九月 04,2013 9:26:10 上午 org.apache.catalina.core.StandardWrapperValve invoke
SEVERE:Servlet.service() for servlet jsp threw exception
java.lang.NullPointerException
运行result.jsp报错,烦请大家帮忙看看具体是什么错误,

JSP页面第13行的for循环没有关闭.应该如下：

   for(int i=0; i < books.size(); i++){
        Book book = books.get(i);

   }
再问： 您再看看  他的括号 是不是25行那个？但是报错的信息又是13行的
再答： 怀疑是：books这个对象为空。 也就是从session中没有取到books的值。

你在for循环之前加个调试信息，看看   <%=book%> 或 <%=book.size()%>