HTTP状态500-实例化servlet类java.reg.pkg.Hello时出错

HTTP状态500-实例化servlet类java.reg.pkg.Hello时出错,java,servlets,Java,Servlets,我试图在eclipse中执行一个servlet程序,但是我得到了一个HTTP status 500错误 请查找我的目录结构: 练习 | Java资源 | src | javs.reg.pkg | Hello.java 我的web.xml是: <?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java

我试图在eclipse中执行一个servlet程序,但是我得到了一个HTTP status 500错误

请查找我的目录结构:

练习 | Java资源 | src | javs.reg.pkg | Hello.java

我的web.xml是:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
  <display-name>Practice1_servlet</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
  <servlet>
      <servlet-name>Hello1</servlet-name>
    <servlet-class>java.reg.pkg.Hello</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>Hello1</servlet-name>
    <url-pattern>/hello</url-pattern>
  </servlet-mapping>
</web-app>
你知道问题出在哪里吗

上述程序的堆栈跟踪:

HTTP状态500-实例化servlet类java.reg.pkg.Hello时出错

类型异常报告

实例化servlet类java.reg.pkg.Hello时出错

说明服务器遇到内部错误,无法满足此请求

例外情况

javax.servlet.ServletException:实例化servlet类时出错 java.reg.pkg.Hello org.apache.catalina.authenticator.AuthenticatorBase.invokeAuthenticatorBase.java:501 org.apache.catalina.valves.ErrorReportValve.invokeErrorReportValve.java:98 org.apache.catalina.valves.AccessLogValve.invokeAccessLogValve.java:950 org.apache.catalina.connector.CoyoteAdapter.serviceCoyoteAdapter.java:408 org.apache.coyote.http11.AbstractHttp11Processor.processAbstractHttp11Processor.java:1040 org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.processAbstractProtocol.java:607 org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.runJIoEndpoint.java:313 java.util.concurrent.ThreadPoolExecutor.runWorkerUnknown源 java.util.concurrent.ThreadPoolExecutor$Worker.runUnknown源 java.lang.Thread.runUnknown源

根本原因

java.lang.ClassNotFoundException:java.reg.pkg.Hello org.apache.catalina.loader.WebappClassLoader.loadClassWebappClassLoader.java:1718 org.apache.catalina.loader.WebappClassLoader.loadClassWebappClassLoader.java:1569 org.apache.catalina.authenticator.AuthenticatorBase.invokeAuthenticatorBase.java:501 org.apache.catalina.valves.ErrorReportValve.invokeErrorReportValve.java:98 org.apache.catalina.valves.AccessLogValve.invokeAccessLogValve.java:950 org.apache.catalina.connector.CoyoteAdapter.serviceCoyoteAdapter.java:408 org.apache.coyote.http11.AbstractHttp11Processor.processAbstractHttp11Processor.java:1040 org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.processAbstractProtocol.java:607 org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.runJIoEndpoint.java:313 java.util.concurrent.ThreadPoolExecutor.runWorkerUnknown源 java.util.concurrent.ThreadPoolExecutor$Worker.runUnknown源 java.lang.Thread.runUnknown源

注意,Apache Tomcat/7.0.52日志中提供了根本原因的完整堆栈跟踪


我使用的是ApacheTomcat/7.0.52。

我认为这是一个错误的名称。您的servlet名为Hello,位于java.reg.pkg中,而堆栈跟踪则指示它在java.sample.pkg包中加载名为SampleHello的servlet


您提供的web.xml没有后一个servlet的跟踪,因此出现ClassNotFoundException错误…

尝试清理项目并运行。如果您正在使用eclipse Project->Clean

发布堆栈跟踪。在编辑部分发布堆栈跟踪如果我在eclipse中复制并粘贴您的代码,我不会得到500…我在其他pc中尝试过,但没有得到500错误。但是为什么我的机器会给出500错误?对不起,我昨天发布了错误的堆栈跟踪。请在上面找到正确的堆栈跟踪。
package java.reg.pkg;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class Hello
 */
public class Hello extends HttpServlet {
    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#HttpServlet()
     */
    public Hello() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setContentType("type/html");
        PrintWriter out = response.getWriter();
        out.println("Hello World");
        // TODO Auto-generated method stub
    }

}