debugger resources are 404 not found

[wmh]

I have tool.debugger = true in the configuration and append ?ddl-debug to the url to enable debugger. Resource files are appended to html, but all of them are 404 not found. Any thing I can do with this?

[tduchateau]

Are you sure to deploy on a Servlet 3.x compatible container?
Is your web.xml file configured for the Servlet 3. API?

<web-app 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_3_0.xsd"
         version="3.0">
...
</web-app>

[wmh]

I'm using the lastest version of spring boot and without web.xml configuration. The embed tomcat is 8.0.2x. I think it's Servlet 3.x.

[tduchateau]

I think it comes from the Servlet API version. Let me try to reproduce and I get back to you.

[tduchateau]

I've tested with the spring-boot-sample-tomcat sample app.

I've just added the following configuration class:

@Configuration
public class DandelionConfig {

   @Bean
   public FilterRegistrationBean dandelionFilterRegistrationBean() {
      return new FilterRegistrationBean(new DandelionFilter());
   }

   @Bean
   public FilterRegistrationBean datatableFilterRegistrationBean() {
      return new FilterRegistrationBean(new DatatablesFilter());
   }

   @Bean
   public ServletRegistrationBean dandelionServletRegistrationBean() {
      return new ServletRegistrationBean(new DandelionServlet(), "/dandelion-assets/*");
   }
}

No particular issue with the debugger. Do you know what could differ between your app and the above sample?

Spring Boot: 1.3.0.BUILD
Dandelion: 1.1.0
Tomcat embedded: 8.0.23

[wmh]

I have the same configuration in my project and I also have some other custom filters and interceptors, I don't know if that will be the problem. How can I debug for this?

[tduchateau]

Interesting. Could you please try to configure the filter as the first one in the filter chain?

@Bean
public FilterRegistrationBean dandelionFilterRegistrationBean() {
      FilterRegistrationBean registrationBean = new FilterRegistrationBean();
      DandelionFilter dandelionFilter = new DandelionFilter();
      registrationBean.setFilter(dandelionFilter);
      registrationBean.setOrder(0);
      return registrationBean;
}

[wmh]

I found that my own resource handler cause the problem, how can I adopt the debugger with the resource handler?

This is the resource handler:

@Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
    String verPrefix = myConf.getVersion();
    registry.addResourceHandler(verPrefix + "/**").addResourceLocations("classpath:/public/");
    registry.addResourceHandler("/**").addResourceLocations("classpath:/public/");
}

[tduchateau]

Try:

registry.addResourceHandler("/ddl-debugger/**").addResourceLocations("/ddl-debugger/");

The above will only work in a Servlet 3.x container. So it should work with Spring Boot.

[wmh]

It's not working, still 404 not found. 😢

[tduchateau]

I'm wondering if it's an ordering issue or not..

What happens if you declare the most specific rule in first?

@Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
    String verPrefix = myConf.getVersion();
    registry.addResourceHandler("/ddl-debugger/**").addResourceLocations("/ddl-debugger/");
    registry.addResourceHandler(verPrefix + "/**").addResourceLocations("classpath:/public/");
    registry.addResourceHandler("/**").addResourceLocations("classpath:/public/");
}

[wmh]

I have tried but the result is the same.

[tduchateau]

Some logs would help. Could you please turn on DEBUG logs on org.springframework.web and post what happens while trying to access the debugger?

[wmh]

one of the resource file:

15:29:22.265 [http-nio-8080-exec-8] DEBUG [org.springframework.web.servlet.DispatcherServlet]: 861 - DispatcherServlet with name 'dispatcherServlet' processing GET request for [/ddl-debugger/js/d3.min.js]
15:29:22.266 [http-nio-8080-exec-8] DEBUG [org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping]: 294 - Looking up handler method for path /ddl-debugger/js/d3.min.js
15:29:22.268 [http-nio-8080-exec-8] DEBUG [org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping]: 302 - Did not find handler method for [/ddl-debugger/js/d3.min.js]
15:29:22.269 [http-nio-8080-exec-8] DEBUG [org.springframework.web.servlet.handler.SimpleUrlHandlerMapping]: 168 - Matching patterns for request [/ddl-debugger/js/d3.min.js] are [/ddl-debugger/**, /**]
15:29:22.269 [http-nio-8080-exec-8] DEBUG [org.springframework.web.servlet.handler.SimpleUrlHandlerMapping]: 193 - URI Template variables for request [/ddl-debugger/js/d3.min.js] are {}
15:29:22.269 [http-nio-8080-exec-8] DEBUG [org.springframework.web.servlet.handler.SimpleUrlHandlerMapping]: 123 - Mapping [/ddl-debugger/js/d3.min.js] to HandlerExecutionChain with handler [ResourceHttpRequestHandler [locations=[ServletContext resource [/ddl-debugger/]], resolvers=[org.springframework.web.servlet.resource.PathResourceResolver@b16770]]] and 1 interceptor
15:29:22.269 [http-nio-8080-exec-8] DEBUG [org.springframework.web.servlet.DispatcherServlet]: 947 - Last-Modified value for [/ddl-debugger/js/d3.min.js] is: -1
15:29:22.269 [http-nio-8080-exec-8] DEBUG [org.springframework.web.servlet.DispatcherServlet]:1034 - Null ModelAndView returned to DispatcherServlet with name 'dispatcherServlet': assuming HandlerAdapter completed request handling
15:29:22.269 [http-nio-8080-exec-8] DEBUG [org.springframework.web.servlet.DispatcherServlet]: 997 - Successfully completed request
15:29:22.270 [http-nio-8080-exec-8] DEBUG [org.springframework.web.servlet.DispatcherServlet]: 861 - DispatcherServlet with name 'dispatcherServlet' processing GET request for [/error]
...

[tduchateau]

Thanks!
I think I got it. Could please try to configure a default servlet handler?

Using JavaConfig:

public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
   configurer.enable(); 
}

Or XML:

<mvc:default-servlet-handler/>

Then the custom resource handler for Dandelion shouldn't be needed.