在线等待！！！jsp页面链接传送数据问题！！！

有一booklist.jsp文件，列出书名、ISBN等基本信息，并提供链接以显示详细图书详细信息，
通过ISBN来传递。
booklist.jsp
链接语句如下：
<a href="bookmx.jsp?isbn_id=<%= b_isbn %>">，b_isbn为string类型。
bookmx.jsp
接收语句如下：
string isbnid=request.getParameter("isbn_id");

运行后出错信息：
type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

org.apache.jasper.JasperException: Unsupported encoding:
org.apache.jasper.compiler.DefaultErrorHandler.jspError(DefaultErrorHandler.java:94)
org.apache.jasper.compiler.ErrorDispatcher.dispatch(ErrorDispatcher.java:404)
org.apache.jasper.compiler.ErrorDispatcher.jspError(ErrorDispatcher.java:154)
org.apache.jasper.compiler.JspUtil.getReader(JspUtil.java:1062)
org.apache.jasper.compiler.ParserController.parse(ParserController.java:242)
org.apache.jasper.compiler.ParserController.parse(ParserController.java:149)
org.apache.jasper.compiler.ParserController.parse(ParserController.java:135)
org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:237)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:456)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:439)
org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:552)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:291)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:301)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:248)
javax.servlet.http.HttpServlet.service(HttpServlet.java:856)


note The full stack trace of the root cause is available in the Tomcat logs.

因本人为新手，请各位不吝指教。先谢了。