严重：为 servlet <myservlet-name> java.lang.ClassNotFoundException 分配异常：<myservlet> 异常
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/24942153/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
SEVERE: Allocate exception for servlet <myservlet-name> java.lang.ClassNotFoundException: <myservlet> exception
提问by John
When I use the following web.xml, my project runs fine and I can see "Hello World" getting displayed via index.jsp page. I am using Netbeans 7.4and Apache tomcat 6.0.41
当我使用以下内容时web.xml，我的项目运行良好，我可以看到通过 index.jsp 页面显示“Hello World”。我正在使用Netbeans 7.4和Apache tomcat 6.0.41
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
<session-config>
<session-timeout>
30
</session-timeout>
</session-config>
</web-app>
However, when I created my own servlet and use the following web.xml,=
但是，当我创建自己的 servlet 并使用以下内容时web.xml，=
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
<session-config>
<session-timeout>
30
</session-timeout>
</session-config>
<servlet>
<servlet-name>TEST_Authenticate</servlet-name>
<servlet-class>restapi.TEST_Authenticate</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>TEST_Authenticate</servlet-name>
<url-pattern>/TEST_Authenticate</url-pattern>
</servlet-mapping>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.0.1</version>
<scope>provided</scope>
</dependency>
I end up getting the following error in the Apache Tomcat Log:
我最终在 Apache Tomcat 日志中收到以下错误：
Jul 24, 2014 9:36:14 AM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Allocate exception for servlet TEST_Authenticate
java.lang.ClassNotFoundException: TEST_Authenticate
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1680)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1526)
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1128)
at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:827)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:129)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:861)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:606)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Thread.java:744)
I have checked the following postbut still getting the errors.
我已经检查了以下帖子，但仍然出现错误。
Project Structure :
项目结构：
采纳答案by SparkOn
First of all remove
首先删除
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.0.1</version>
<scope>provided</scope>
</dependency>
from the web.xmland put it in your pom.xmlif it is a Maven project.
从web.xml并把它放在你的pom.xml，如果它是一个Maven项目。
Secondly, ClassNotFoundExceptionis thrown when the class cannot be found in the specified location. In your case, as you have
其次，ClassNotFoundException在指定位置找不到类时抛出。在你的情况下，正如你所拥有的
<servlet-class>restapi.TEST_Authenticate</servlet-class>
So, I am assuming that you have a package of name restapiand under which you have the class TEST_Authenticate.
因此，我假设您有一个 name 包，restapi并且在该包下有 class TEST_Authenticate。
So, if it is a Maven project
you should have scr/main/java/yourpackagename/yourClassand if it is a simple web-project then it should be like src/yourpackagename/yourClass.
所以，如果它是一个 Maven 项目，你应该有scr/main/java/yourpackagename/yourClass，如果它是一个简单的网络项目，那么它应该像src/yourpackagename/yourClass.
回答by Am_I_Helpful
You haven't closed the <web-api>in web.xmlusing /web-api>at the end. SO,it might be giving error. Also,it is better to keep <session-config>after the servlet-mappingparameters.
你最后还没有关闭<web-api>in web.xmlusing /web-api>。所以，它可能会出错。此外，最好保留<session-config>在servlet-mapping参数之后。
Just try the following piece of code in web.xml(COPY-PASTE my code in your web.xml) :-
只需在web.xml(COPY-PASTE my code in your web.xml) 中尝试以下代码：-
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="3.1" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd">
<welcome-file-list>
<welcome-file>restapi/TEST_Authenticate.java</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>TEST_Authenticate</servlet-name>
<servlet-class>restapi.TEST_Authenticate</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>TEST_Authenticate</servlet-name>
<url-pattern>/TEST_Authenticate</url-pattern>
</servlet-mapping>
<session-config>
<session-timeout>30</session-timeout>
</session-config>
</web-app>
EDIT --->
编辑--->
By default,the welcome page is set to index.jspin a web-application project in NetBeans IDE. So,if you don't specify anything even then it'll search for that file only and open it. If you want to open a specific page,edit the
默认情况下，欢迎页面设置index.jsp在 NetBeans IDE 中的 Web 应用程序项目中。因此，如果您没有指定任何内容，那么它只会搜索该文件并打开它。如果要打开特定页面，请编辑
<welcome-file-list>
<welcome-file>login.jsp</welcome-file>
</welcome-file-list>
<welcome-file-list>
<welcome-file>login.jsp</welcome-file>
</welcome-file-list>
and replace the login.jspwith your_required_jsp_page.
并将 替换为login.jspyour_required_jsp_page。
I hope it answers your question. Feel free to comment if it doesn't help.
我希望它能回答你的问题。如果没有帮助，请随时发表评论。
