java - 如何为spring配置web.xml

Question

我是 spring 框架的新手，在通过 web.xml 链接/配置 springframework 时遇到问题。 运行我的应用程序时出现以下错误。

错误:

HTTP Status 500 - Error instantiating servlet class org.springframework.web.servlet.DispatcherServlet


    type Exception report

    message Error instantiating servlet class org.springframework.web.servlet.DispatcherServlet

    description The server encountered an internal error (Error instantiating servlet class org.springframework.web.servlet.DispatcherServlet) that prevented it from fulfilling this request.

    exception 

    javax.servlet.ServletException: Error instantiating servlet class org.springframework.web.servlet.DispatcherServlet
        org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
        org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
        org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
        org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
        org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1001)
        org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:585)
        org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
        java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
        java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
        java.lang.Thread.run(Unknown Source)


    root cause 

    java.lang.ClassNotFoundException: org.springframework.web.servlet.DispatcherServlet
        org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1711)
        org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1556)
        org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
        org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
        org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
        org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
        org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1001)
        org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:585)
        org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
        java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
        java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
        java.lang.Thread.run(Unknown Source)

显然，它在库中找不到类 org.springframework.web.servlet.DispatcherServlet。但是，我不知道如何告诉 web.xml 在哪里查找此类。

web.xml

    <?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" 
             xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" 
             xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">

        <servlet>
            <servlet-name>DispatcherSample</servlet-name>
            <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        </servlet>

        <servlet-mapping>
            <servlet-name>DispatcherSample</servlet-name>
            <url-pattern>/PlayField.html</url-pattern>
        </servlet-mapping>

      <welcome-file-list>
        <welcome-file>index.html</welcome-file>
        <welcome-file>Welcome.html</welcome-file>
      </welcome-file-list>

    </web-app>

DispatcherSample-servlet.xml

    <?xml version="1.0" encoding="UTF-8"?>

    <beans xmlns="http://www.springframework.org/schema/beans"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">

        <bean id="handlerMapping" class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">  
            <property name="mappings">
                <props>
                    <prop key="/PlayField.html">playfieldController</prop>
                </props>    
            </property>
        </bean>

        <bean id="playfieldController" class="demos.PlayfieldController"/>

    </beans>

Answer 1

java.lang.ClassNotFoundException: org.springframework.web.servlet.DispatcherServlet

您必须添加spring-webmvc.jar到您的 CLASSPATH(最有可能是 /WEB-INF/lib 目录)。您的其余配置看起来不错。