Question

HTTP Status 500 - Unable to compile class for JSP

好的，有很多关于这个错误的文章，我还是个新手。我播种这个错误可能是由于某种不同的原因引起的，这是我（可能是愚蠢的或已经存在的）原因：

它找不到类，显然是从NetBeans导入的。

<%@ page import="mypack.Display" %>

事实上，如果我查看缓存文件“index_jsp.java”，问题就在于“ import mypack.Display; ”。我的问题与此What causes this jsp Error 500?非常相似，区别在于我没有将 mypack.Display 放入默认包中，然后我不知道为什么会出现此错误。

这是我的 index.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>JSP Page</title>
    </head>
    <body>
        <h1><% out.print("jsp class test");%></h1>
        <%@ page import="mypack.Display" %>   
        <%
            Display t = new Display();
            t.test("Roby");
        %>
    </body>
</html>

这是简单的 Display.java

package mypack;

public class Display{

  public void test(String msg){
    System.out.println("My name is "+msg);
  }
 }

我的一位朋友说我应该将 servlet 配置到 web.xml 文件中的WEB-INF文件夹中，但查看样本我没有'我明白我是怎么做到的。我是否必须将包映射到该文件中？

我将 Display.java 放在Netbeans正确采用的“mypack”包下，实际上如果我尝试在index.jsp和Display中更改类或包名称.java，编译器向我显示错误。

有人可以帮助我，以便更好地理解吗？

完整错误下方：

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: 14 in the generated java file
Only a type can be imported. mypack.Display resolves to a package

An error occurred at line: 19 in the jsp file: /index.jsp
Display cannot be resolved to a type
16:         <%--<jsp:useBean id="link" scope="application" class = "mypack.Display" />--%>
17:         <%@ page import="mypack.Display" %>   
18:         <%
19:             Display t = new Display();
20:             t.test("Roby");
21: //          out.println(outpt);
22:         %>


An error occurred at line: 19 in the jsp file: /index.jsp
Display cannot be resolved to a type
16:         <%--<jsp:useBean id="link" scope="application" class = "mypack.Display" />--%>
17:         <%@ page import="mypack.Display" %>   
18:         <%
19:             Display t = new Display();
20:             t.test("Roby");
21: //          out.println(outpt);
22:         %>


Stacktrace:
    org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:102)
    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:728)

note The full stack trace of the root cause is available in the Apache Tomcat/7.0.35 logs.

HTTP状态500 - 无法为JSP编译类

0 个答案: