Question

我试图通过使用JSP扩展页面指令来做一个例子，首先，我在项目源区域中构建了一个简单的java类文件。 Project正在Eclipse IDE中构建。

代码在这里：

package com.coderbd.extend;

public class Test {

    public String testMethod(){
        return "Hello";
    }

}

首先在JSP页面，我使用扩展页面指令扩展了类，如：<%@ page extends="com.coderbd.extend.Test" %> 然后在我的index.jsp页面中，我创建了Test类的对象，如：

<%
    Test t= new Test();
    t.testMethod();
%>

最后试图打印：

<%
    out.println(""+ testMethod());
%>

我在lib WEB-INF文件夹下的jasper.jar使用了以下广告罐。

org.apache.jasper.jar
javax.servlet-api-3.0.jar
javax.el-api.jar
javax.servlet-3.0.jar
HTTP Status 500 - Unable to compile class for JSP: type Exception report message Unable to compile class for JSP: description The server encountered an internal error that prevented it from fulfilling this request. exception org.apache.jasper.JasperException: Unable to compile class for JSP: An error occurred at line: [32] in the generated java file: [E:\The Java Spring Tutorial Learn Java's Popular Web Framework\JSP\work-space\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\work\Catalina\localhost\jsp-sec-4-lec-3\org\apache\jsp\index_jsp.java] The method getServletConfig() is undefined for the type index_jsp An error occurred at line: [33] in the generated java file: [E:\The Java Spring Tutorial Learn Java's Popular Web Framework\JSP\work-space\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\work\Catalina\localhost\jsp-sec-4-lec-3\org\apache\jsp\index_jsp.java] The method getServletConfig() is undefined for the type index_jsp An error occurred at line: [54] in the generated java file: [E:\The Java Spring Tutorial Learn Java's Popular Web Framework\JSP\work-space\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\work\Catalina\localhost\jsp-sec-4-lec-3\org\apache\jsp\index_jsp.java] The method getPageContext(Servlet, ServletRequest, ServletResponse, String, boolean, int, boolean) in the type JspFactory is not applicable for the arguments (index_jsp, HttpServletRequest, HttpServletResponse, null, boolean, int, boolean) Stacktrace: org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:103) org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:331) org.apache.jasper.compiler.JDTCompiler.generateClass(JDTCompiler.java:468) org.apache.jasper.compiler.Compiler.compile(Compiler.java:378) org.apache.jasper.compiler.Compiler.compile(Compiler.java:353) org.apache.jasper.compiler.Compiler.compile(Compiler.java:340) org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:646) org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:357) org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390) org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334) javax.servlet.http.HttpServlet.service(HttpServlet.java:727) org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

但是我知道，我的Tomcat服务器出现以下错误：

{{1}}

请帮我修复使用jsp extends page指令的例子。

Answer 1

从WEB-INF / lib中删除所有这些jar。这些是Tomcat内部使用的jar文件。它们不应该在您的webapp中。

并删除extends="com.coderbd.extend.Test"：它没有任何意义。您的JSP创建了Test和使用的实例。它不需要（并且不能）扩展它。

Jsp扩展页面指令异常：无法为JSP编译类：

1 个答案: