JstlUtils.java 文件源码

/**
 * Checks JSTL's "javax.servlet.jsp.jstl.fmt.localizationContext"
 * context-param and creates a corresponding child message source,
 * with the provided Spring-defined MessageSource as parent.
 * @param servletContext the ServletContext we're running in
 * (to check JSTL-related context-params in {@code web.xml})
 * @param messageSource the MessageSource to expose, typically
 * the ApplicationContext of the current DispatcherServlet
 * @return the MessageSource to expose to JSTL; first checking the
 * JSTL-defined bundle, then the Spring-defined MessageSource
 * @see org.springframework.context.ApplicationContext
 */
public static MessageSource getJstlAwareMessageSource(
        ServletContext servletContext, MessageSource messageSource) {

    if (servletContext != null) {
        String jstlInitParam = servletContext.getInitParameter(Config.FMT_LOCALIZATION_CONTEXT);
        if (jstlInitParam != null) {
            // Create a ResourceBundleMessageSource for the specified resource bundle
            // basename in the JSTL context-param in web.xml, wiring it with the given
            // Spring-defined MessageSource as parent.
            ResourceBundleMessageSource jstlBundleWrapper = new ResourceBundleMessageSource();
            jstlBundleWrapper.setBasename(jstlInitParam);
            jstlBundleWrapper.setParentMessageSource(messageSource);
            return jstlBundleWrapper;
        }
    }
    return messageSource;
}