Spring isn't loading CSS and gives a 404 when the page is loaded

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I'm running a Spring (not Boot) web app and it's finding my JSP views properly, but my CSS isn't being found for some reason. To be clear, the page is loading with the necessary elements, but any CSS styling from classes in my .css files is not being applied. The structure for the CSS file I'm trying to use is src/main/resources/css/style.css .

Below is the relevant code for my AppConfig class:

public class AppConfig implements WebMvcConfigurer {
    ...
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/css/**")
                .addResourceLocations("/css/");
    }
    ...
}

And the JSP header:

 <link type="text/css" rel="stylesheet" href="${pageContext.request.contextPath}/css/style.css"/>

I've already checked some other questions asking after this issue and have had no luck. Several of them advised checking the config file for Spring Security to ensure that permission is granted for all requests using the resource file but based on what I can see, it shouldn't be prohibiting the CSS from being loaded:

@Configuration
@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {

    @Autowired
    private UserService userService;

    @Bean
    public BCryptPasswordEncoder encoder() {
        return new BCryptPasswordEncoder();
    }

    @Override
    protected void configure(AuthenticationManagerBuilder auth) throws Exception {
        auth.authenticationProvider(authenticationProvider());
    }

    @Override
    protected void configure(HttpSecurity http) throws Exception {
    }

    @Bean
    public DaoAuthenticationProvider authenticationProvider() {
        DaoAuthenticationProvider authenticationProvider = new DaoAuthenticationProvider();
        authenticationProvider.setPasswordEncoder(encoder());
        authenticationProvider.setUserDetailsService(userService);

        return authenticationProvider;
    }

}

Answer 1

You need to tell spring security to ignore css files by overriding this method in WebSecurityConfigurerAdapter:

 @Override
 public void configure(WebSecurity web) throws Exception {
        web.ignoring().antMatchers("/resources/**", "/static/**", "/css/**", "/js/**", "/images/**","/vendor/**","/fonts/**").anyRequest();
 }

Answer 2

The configuration that you posted in your question:

public class AppConfig implements WebMvcConfigurer {
    ...
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/css/**")
                .addResourceLocations("/css/");
    }
    ...
}

tells Spring MVC to serve /css/style.css from the css directory in your context directory. If it doesn't exist, you get a 404.

If you want to serve the file from the classpath (which is what your question seems to imply), then you should do this instead:

public class AppConfig implements WebMvcConfigurer {
    ...
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/css/**")
                .addResourceLocations("classpath:/resources/css/");
    }
    ...
}

See the documentation of ResourceHandlerRegistry for more details.

Answer 3

For a non-Spring Boot project your css folder should be not in src/main/resources but in src/main/webapp .