在SpringMVC的源代码中也提供了一个封装过的ThreadLocal，其中保存了每次请求的HttpServletRequest对象，（详细请看org.springframework.web.context.request.ServletRequestAttributes的源代码） 。这样我们就可以进行简单封装一下写一个工具进行使用：*当然必不可少的一点一定记得，在web.xml里必须要有相应的配置来支持 
           
      
       org.springframework.web.context.request.RequestContextListener
        
       工具类代码：package samples.utils;    import java.util.Arrays;  import java.util.Collection;  import java.util.Locale;    import javax.servlet.ServletContext;  import javax.servlet.http.HttpServletRequest;  import javax.servlet.http.HttpSession;  import javax.sql.DataSource;    import org.slf4j.Logger;  import org.slf4j.LoggerFactory;  import org.springframework.beans.factory.NoSuchBeanDefinitionException;  import org.springframework.beans.factory.NoUniqueBeanDefinitionException;  import org.springframework.context.ApplicationContext;  import org.springframework.context.ApplicationEventPublisher;  import org.springframework.context.MessageSource;  import org.springframework.core.convert.ConversionService;  import org.springframework.core.io.ResourceLoader;  import org.springframework.core.io.support.ResourcePatternResolver;  import org.springframework.ui.context.Theme;  import org.springframework.util.ClassUtils;  import org.springframework.web.context.request.RequestContextHolder;  import org.springframework.web.context.request.ServletRequestAttributes;  import org.springframework.web.context.support.WebApplicationContextUtils;  import org.springframework.web.servlet.LocaleResolver;  import org.springframework.web.servlet.ThemeResolver;  import org.springframework.web.servlet.support.RequestContextUtils;      /**  * SpringMVC通用工具  * @author  */  public final class WebContextHolder {            private static final Logger LOGGER = LoggerFactory.getLogger(WebContextHolder.class);           private static final WebContextHolder INSTANCE = new WebContextHolder();            public WebContextHolder get() {          return INSTANCE;      }        private WebContextHolder() {          super();      }            // --------------------------------------------------------------------------------------------------------------            public HttpServletRequest getRequest() {          ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder.currentRequestAttributes();        return attributes.getRequest();      }            public HttpSession getSession() {          return getSession(true);      }            public HttpSession getSession(boolean create) {          return getRequest().getSession(create);      }            public String getSessionId() {          return getSession().getId();      }            public ServletContext getServletContext() {          return getSession().getServletContext();    // servlet2.3      }            public Locale getLocale() {          return RequestContextUtils.getLocale(getRequest());      }            public Theme getTheme() {          return RequestContextUtils.getTheme(getRequest());      }        public ApplicationContext getApplicationContext() {          return WebApplicationContextUtils.getWebApplicationContext(getServletContext());      }            public ApplicationEventPublisher getApplicationEventPublisher() {          return (ApplicationEventPublisher) getApplicationContext();      }            public LocaleResolver getLocaleResolver() {          return RequestContextUtils.getLocaleResolver(getRequest());      }            public ThemeResolver getThemeResolver() {          return RequestContextUtils.getThemeResolver(getRequest());      }            public ResourceLoader getResourceLoader() {          return (ResourceLoader) getApplicationContext();      }            public ResourcePatternResolver getResourcePatternResolver() {          return (ResourcePatternResolver) getApplicationContext();      }        public MessageSource getMessageSource() {          return (MessageSource) getApplicationContext();      }            public ConversionService getConversionService() {          return getBeanFromApplicationContext(ConversionService.class);      }        public DataSource getDataSource() {          return getBeanFromApplicationContext(DataSource.class);      }        public Collection
     
       getActiveProfiles() {          return Arrays.asList(getApplicationContext().getEnvironment().getActiveProfiles());      }            public ClassLoader getBeanClassLoader() {          return ClassUtils.getDefaultClassLoader();      }        private 
      
        T getBeanFromApplicationContext(Class
       
         requiredType) {          try {              return getApplicationContext().getBean(requiredType);          } catch (NoUniqueBeanDefinitionException e) {              LOGGER.error(e.getMessage(), e);              throw e;          } catch (NoSuchBeanDefinitionException e) {              LOGGER.warn(e.getMessage());              return null;          }      }    }