当前位置: 首页 > 面试题库 >

ClassCastException:无法将DispatcherServlet强制转换为Servlet

荣声
2023-03-14
问题内容

我使用maven-eclipse创建了一个新的Spring MVC项目,并引发以下错误:

(我尝试了stackoverflow的一些解决方案,但这些解决方案在我的情况下不起作用。pom.xml出现了一些我找不到的问题。我为servlet-
api添加了提供的作用域,并尝试了它也不起作用。)

SEVERE: Servlet /Remindem threw load() exception
java.lang.ClassCastException: org.springframework.web.servlet.DispatcherServlet 
  cannot be cast to javax.servlet.Servlet

我的pom.xml如下:

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>

<groupId>com.org</groupId>
<artifactId>Remindem</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>

<name>Remindem</name>
<url>http://maven.apache.org</url>

<dependencies>
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>javax.servlet-api</artifactId>
        <version>3.0.1</version>
        <scope>compile</scope>
    </dependency>
    <dependency>
        <groupId>javax.servlet.jsp</groupId>
        <artifactId>jsp-api</artifactId>
        <version>2.1</version>
    </dependency>
    <dependency>
        <groupId>org.apache.maven</groupId>
        <artifactId>maven-plugin-api</artifactId>
        <version>2.0</version>
    </dependency>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>3.8.1</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-core</artifactId>
        <version>3.6.8.Final</version>
    </dependency>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-validator</artifactId>
        <version>4.0.0.Beta2</version>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.6</version>
    </dependency>
    <dependency>
        <groupId>javassist</groupId>
        <artifactId>javassist</artifactId>
        <version>3.12.1.GA</version>
    </dependency>
    <dependency>
        <groupId>javax.mail</groupId>
        <artifactId>mail</artifactId>
        <version>1.4</version>
    </dependency>

    <!-- Spring framework -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring</artifactId>
        <version>2.5.6</version>
        <scope>compile</scope>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-web</artifactId>
        <version>2.5.6</version>
        <scope>compile</scope>

    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
        <version>3.2.3.RELEASE</version>
        <scope>compile</scope>
    </dependency>


    <!-- Spring MVC framework -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>2.5.6</version>
        <scope>compile</scope>
    </dependency>

    <!-- JSTL -->
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>jstl</artifactId>
        <version>1.1.2</version>
    </dependency>

    <dependency>
        <groupId>taglibs</groupId>
        <artifactId>standard</artifactId>
        <version>1.1.2</version>
    </dependency>

    <dependency>
        <groupId>org.apache.tomcat</groupId>
        <artifactId>tomcat-api</artifactId>
        <version>7.0.19</version>
    </dependency>
</dependencies>

<build>
    <plugins>
<plugin>
    <groupId>org.apache.tomcat.maven</groupId>
    <artifactId>tomcat7-maven-plugin</artifactId>
    <version>2.0</version>
    <configuration>
      <url>http://localhost:8080/Remindem</url>
    </configuration>
  </plugin>
    </plugins>
</build>

我的web.xml如下:

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">

<display-name>Remindem</display-name>
<session-config>
    <session-timeout>
        30
    </session-timeout>
</session-config>
<welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>

     <servlet>
        <servlet-name>svn</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>
                /WEB-INF/SpringAppServlet.xml               
            </param-value>
        </init-param>
    <load-on-startup>1</load-on-startup>
</servlet>

 <servlet-mapping>
    <servlet-name>svn</servlet-name>
    <url-pattern>/*</url-pattern>
</servlet-mapping>

 <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

</web-app>

问题答案:

更改

<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>javax.servlet-api</artifactId>
    <version>3.0.1</version>
    <scope>compile</scope>
</dependency>

<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>javax.servlet-api</artifactId>
    <version>3.0.1</version>
    <scope>provided</scope>
</dependency>

provided 具有以下说明:

这很像编译,但是表明您希望JDK或容器在运行时提供依赖项。例如,在为Java Enterprise
Edition构建Web应用程序时,您将对Servlet API和相关Java EE
API的依赖关系设置为提供的范围,因为Web容器提供了这些类。此作用域仅在编译和测试类路径上可用,并且不可传递。

来自maven docs。您基本上是在告诉Maven提供jar进行编译,但是在运行时,请使用其他一些servlet容器的jar。



 类似资料: