Shulou(Shulou.com)06/01 Report--

This article mainly explains "how to access css static files". The explanation content in this article is simple and clear, easy to learn and understand. Please follow the ideas of Xiaobian slowly and deeply to study and learn "how to access css static files" together!

If your DispatcherServlet intercepts URLs with suffixes like "*.do," there is no problem of not accessing static resources.

If your DispatcherServlet intercepts "/," blocking all requests for REST style, then access to static files such as *.js,*.jpg, etc. is also blocked.

We need to fix this.

Scenario 1: Activate Tomcat's defaultServlet to process static files

default *.jpg default *.js default *.css To configure multiple, configure one for each file type

To write in front of DispatcherServlet, let defaultServlet intercept the request first, so that the request does not enter Spring, I think the performance is the best.

Solution 2: mvc:resources is provided in versions after spring 3.0.4, using the method:

/images/** Map to ResourceHttpRequestHandler for processing, location specifies the location of the static resource. It can be under the web application root directory or in the jar package, so that static resources can be compressed into the jar package. cache-period enables static resources to be web cached

If the following error occurs, it may be because there is no configuration.

WARNING: No mapping found for HTTP request with URI [/mvc/user/findUser/lisi/770] in DispatcherServlet with name 'springMVC'

Use the element to register the URI of mapping in urlMap of SimpleUrlHandlerMapping,

key is the URI pattern value of mapping, and value is ResourceHttpRequestHandler,

This cleverly transfers access to static resources from HandlerMapping to ResourceHttpRequestHandler and returns, so it supports access to static resources in classpath directory and jar package.

Another thing to note is that do not set defaultHandler for SimpleUrlHandlerMapping. Because defaultHandler for static uri is ResourceHttpRequestHandler,

Otherwise, static resources requests cannot be processed.

Option 3: Use

will put "/** " url, register in urlMap of SimpleUrlHandlerMapping, transfer access to static resources from HandlerMapping to org.springframework.web.servlet.resource.DefaultServletHttpRequestHandler and return.

DefaultServletHttpRequestHandler uses the default Servlet that is the individual Servlet Container's own.

Supplementary note: Multiple HandlerMapping execution order problem:

DefaultAnnotationHandlerMapping's order attribute value is: 0

The automatically registered SimpleUrlHandlerMapping order attribute value is: 2147483646

The automatically registered SimpleUrlHandlerMapping order attribute value is: 2147483647

Spring will execute the order value first. When accessing an a.jpg image file, first look for the processor through DefaultAnnotationHandlerMapping, which must not be found because we do not have an Action called a.jpg. Then look again in ascending order value, since the last SimpleUrlHandlerMapping is a match "/** "Yes, so it will definitely match up, so you can respond to the picture.

To access an image, you have to go through layers of matching. How's the performance?

Finally, when accessing static resources, Scheme 2 and Scheme 3 will take interceptors if there is a matching (approximate) total interceptor. If you implement permission checking in interception, be careful to filter these requests for static files.

If your DispatcherServlet intercepts URL suffixes such as *.do, the above problem does not exist. Or is it convenient to have a suffix?

Thank you for reading, the above is "how to access css static file" content, after the study of this article, I believe we have a deeper understanding of how to access css static file this problem, the specific use of the situation also needs to be verified by practice. Here is, Xiaobian will push more articles related to knowledge points for everyone, welcome to pay attention!

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.