java - Thymeleaf if 表达式不适用于主题参数值

Question

我的应用程序中有一个主题解析器。有两个主题:深色和白色。

<p th:text="${param.theme}">

</p>

这将返回当前主题，深色或白色。然而，

<p th:if="${param.theme == 'white'}">
    white theme
</p>

什么也不输出。

我想要这个来实现主题切换。如何让它发挥作用？

Java配置代码。

public class WebConfig  implements WebMvcConfigurer {

    @Autowired
    private ApplicationContext applicationContext;

    @Bean
    public SpringResourceTemplateResolver templateResolver() {

        var templateResolver = new SpringResourceTemplateResolver();

        templateResolver.setApplicationContext(applicationContext);
        templateResolver.setPrefix("classpath:/templates/");
        templateResolver.setSuffix(".html");

        return templateResolver;
    }

    @Bean
    public SpringTemplateEngine templateEngine() {

        var templateEngine = new SpringTemplateEngine();
        templateEngine.setTemplateResolver(templateResolver());
        templateEngine.setEnableSpringELCompiler(true);

        return templateEngine;
    }

    @Bean
    public ViewResolver viewResolver() {

        var resolver = new ThymeleafViewResolver();
        var registry = new ViewResolverRegistry(null, applicationContext);

        resolver.setTemplateEngine(templateEngine());
        registry.viewResolver(resolver);

        return resolver;
    }

    @Bean
    public ThemeSource themeSource() {

        var themeSource = new ResourceBundleThemeSource();
        themeSource.setBasenamePrefix("themes/");
        return themeSource;
    }

    @Bean
    public ThemeResolver themeResolver(){

        var resolver = new CookieThemeResolver();
        resolver.setCookieMaxAge(604800);
        resolver.setCookieName("mytheme");
        resolver.setDefaultThemeName("dark");
        return resolver;
    }

    @Override
    public void addInterceptors(InterceptorRegistry registry) {

        var themeChangeInterceptor = new ThemeChangeInterceptor();
        themeChangeInterceptor.setParamName("theme");
        registry.addInterceptor(themeChangeInterceptor);
    }

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/css/**").addResourceLocations("classpath:/static/css/");
    }

Answer 1

尝试将主题参数转换为字符串(使用 thymeleaf 表达式 #{} )，然后将其与您的主题名称进行比较

如下:

<p th:if="${#strings.toString(param.theme) == 'white'}">
    white theme
</p>