为什么我在RESIN能够运行的JSP页面在TOMCAT下面却出错呢，代码如下

出错提示如下 ：（tomcat）A Servlet Exception Has Occurred
org.apache.jasper.JasperException: Unsupported encoding: GB2312;
at org.apache.jasper.compiler.ParserController.getReader(Unknown Source)
at org.apache.jasper.compiler.ParserController.parse(Unknown Source)
at org.apache.jasper.compiler.Compiler.compile(Unknown Source)
at org.apache.jasper.servlet.JspServlet.loadJSP(Unknown Source)
at org.apache.jasper.servlet.JspServlet$JspServletWrapper.loadIfNecessary(Unknown Source)
at org.apache.jasper.servlet.JspServlet$JspServletWrapper.service(Unknown Source)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(Unknown Source)
at org.apache.jasper.servlet.JspServlet.service(Unknown Source)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Unknown Source)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(Unknown Source)
at org.apache.catalina.core.StandardWrapperValve.invoke(Unknown Source)
at org.apache.catalina.core.StandardPipeline.invokeNext(Unknown Source)
at org.apache.catalina.core.StandardPipeline.invoke(Unknown Source)
at org.apache.catalina.core.ContainerBase.invoke(Unknown Source)
at org.apache.catalina.core.StandardContextValve.invoke(Unknown Source)
at org.apache.catalina.core.StandardPipeline.invokeNext(Unknown Source)
at org.apache.catalina.valves.CertificatesValve.invoke(Unknown Source)
at org.apache.catalina.core.StandardPipeline.invokeNext(Unknown Source)
at org.apache.catalina.core.StandardPipeline.invoke(Unknown Source)
at org.apache.catalina.core.ContainerBase.invoke(Unknown Source)
at org.apache.catalina.core.StandardContext.invoke(Unknown Source)
at org.apache.catalina.core.StandardHostValve.invoke(Unknown Source)
at org.apache.catalina.core.StandardPipeline.invokeNext(Unknown Source)
at org.apache.catalina.valves.AccessLogValve.invoke(Unknown Source)
at org.apache.catalina.core.StandardPipeline.invokeNext(Unknown Source)
at org.apache.catalina.core.StandardPipeline.invoke(Unknown Source)
at org.apache.catalina.core.ContainerBase.invoke(Unknown Source)
at org.apache.catalina.core.StandardEngineValve.invoke(Unknown Source)
at org.apache.catalina.core.StandardPipeline.invokeNext(Unknown Source)
at org.apache.catalina.core.StandardPipeline.invoke(Unknown Source)
at org.apache.catalina.core.ContainerBase.invoke(Unknown Source)
at org.apache.catalina.connector.http.HttpProcessor.process(Unknown Source)
at org.apache.catalina.connector.http.HttpProcessor.run(Unknown Source)
at java.lang.Thread.run(Thread.java:536)