ssm中web.xml文件的加粗的代码是做什么用的，我删除会报错

Question

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" 
    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_2_5.xsd">
  <!-- 配置spring容器的上下文 -->
  <context-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>classpath:spring-mvc.xml</param-value>
  </context-param>
  <context-param>
        <param-name>spring.profiles.active</param-name>
        <param-value>dev</param-value>
    </context-param>
    <context-param>
        <param-name>spring.profiles.default</param-name>
        <param-value>dev</param-value>
    </context-param>
    <context-param>
        <param-name>spring.liveBeansView.mbeanDomain</param-name>
        <param-value>dev</param-value>
    </context-param>
  <!-- 配置spring的启动项 -->
  <listener>
      <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
  </listener>
  <!-- 配置springmvc的启动配置 -->
   <servlet>
      <servlet-name>dispatcherServlet</servlet-name>
      <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
      <init-param>
          <param-name>contextConfigLocation</param-name>
          <param-value>classpath:spring-bean.xml</param-value>
      </init-param>
      <load-on-startup>1</load-on-startup>
  </servlet>
 <servlet-mapping>
      <servlet-name>dispatcherServlet</servlet-name>
      <url-pattern>*.action</url-pattern>
  </servlet-mapping> 
  <!-- 配置乱码的问题 -->    
  <filter>
      <filter-name>encodingFilter</filter-name>
      <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
      <init-param>
          <param-name>encoding</param-name>
          <param-value>UTF-8</param-value>
      </init-param>
      <init-param>
          <param-name>forceEncoding</param-name>
          <param-value>true</param-value>
      </init-param>
    </filter>
    <filter-mapping>
        <filter-name>encodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
      <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
      </welcome-file-list>
</web-app>
 

控制器报错：

java.lang.annotation.AnnotationFormatError: Unexpected end of annotations.
    at sun.reflect.annotation.AnnotationParser.parseAnnotations(AnnotationParser.java:72)
    at java.lang.reflect.Method.declaredAnnotations(Method.java:714)
    at java.lang.reflect.Method.getAnnotation(Method.java:700)
    at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.buildLifecycleMetadata(InitDestroyAnnotationBeanPostProcessor.java:201)
    at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.findLifecycleMetadata(InitDestroyAnnotationBeanPostProcessor.java:181)
    at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessMergedBeanDefinition(InitDestroyAnnotationBeanPostProcessor.java:124)
    at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessMergedBeanDefinition(CommonAnnotationBeanPostProcessor.java:281)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyMergedBeanDefinitionPostProcessors(AbstractAutowireCapableBeanFactory.java:862)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:512)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:299)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:295)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:195)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:644)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:932)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:493)
    at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:389)
    at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:294)
    at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:106)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:5157)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5680)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1707)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1697)
    at java.util.concurrent.FutureTask.run(FutureTask.java:262)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:745)

Answer 1

让阿豪来帮你解答，本回答参考chatgpt3.5编写提供，如果还有疑问可以评论或留言

根据报错信息"java.lang.annotation.AnnotationFormatError: Unexpected end of annotations"，可以看出是注解格式错误导致的异常。在XML配置中，有一段context-param的配置不符合注解的格式。具体来说，配置了两个context-param标签用来定义spring的profile和liveBeansView，但是在实际使用过程中，这些配置项是通过注解来定义的，而不是在web.xml中配置。 解决方法是删除多余的context-param标签，把这些配置项写入到相应的Java代码中，使用注解的方式进行配置。下面给出示例代码： 定义一个配置类，使用@Configuration注解，并在类中使用@Profile定义profile，@Bean定义liveBeansView：

@Configuration
@Profile("dev")
public class AppConfig {
    
    @Bean
    public LiveBeansView liveBeansView() {
        return new LiveBeansView();
    }
}

在spring-mvc.xml中导入该配置类：

<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">
    <context:annotation-config/>
    <context:component-scan base-package="com.example"/>
    <import resource="classpath:appConfig.java"/>
</beans>

这样就可以通过注解的方式配置spring的profile和liveBeansView，同时避免了在web.xml中配置的错误。