Detailed analysis of the technical principle of W3C Jigsaw framework in the Java class library

W3C Jigsaw is a Java -based open source web server framework that follows the standard of W3C (World Wide Web Consortium).It provides a modular way to build and expand the web server to achieve a highly flexible and customized web application. The main design principle of Jigsaw is based on component models and object -oriented development ideas.It divides the web server into multiple independent components, and each component is responsible for handling specific requests or providing specific functions.These components can create a complete web server through simple configuration and assembly. The core component of Jigsaw is Resource, which means a accessible resource on the web server, such as HTML files, images, videos, etc.Each resource has a unique URI logo and can be accessed with this URI in the web.Resources can embed other resources to form a resource hierarchical structure. In Jigsaw, resources are processed by handler.Handler is a component that implements specific functions, such as handling HTTP requests, parsing HTML files, and executing CGI scripts.When a request arrives, Jigsaw will find the corresponding resource based on the request URI and pass the request to the processor associated with resource association for processing. In addition to Handler, Jigsaw also provides the concept of Filter.Filter is a component for pre -processing and post -processing requests and responses.It can verify the request, authentication, request forwarding and other operations, and can also perform compression, encryption, filtering and other operations in response.Through Filter, dynamic control and expansion of Web server behavior can be achieved. Jigsaw also provides an event mechanism for handling events at different stages.When a request arrives, resource access, response, etc., Jigsaw will trigger the corresponding event and call the registered event processor for processing.This allows flexible adjustments to the behavior of the web server without modifying the source code. To facilitate users to use Jigsaw, it also provides a set of XML -based configuration language.Users can use this configuration language to declare and configure components, including resources, handler, Filter, event processor, etc.Through simple configuration files, it can easily customize and expand the functions of the web server. Below is a simple example code that demonstrates how to use JIGSAW to create a simple web server: import org.w3c.jigsaw.http.*; import org.w3c.www.http.HTTP; import org.w3c.tools.resources.*; public class SimpleServer { public static void main(String[] args) { try { // Create an HTTPSERVER instance HttpServer server = new HttpServer(8080); // Create a rootRsource instance as the root resource of the server Resource root = new RootResource(); // Create a FileReSource instance to indicate a static HTML file FileResource file = new FileResource("index.html", root); // Add FileReSource to the root resource root.addChild(file); // Start the server server.start(); } catch(Exception e) { e.printStackTrace(); } } // Root resource classes static class RootResource extends ContainerResource { public RootResource() { super("/"); } } } This example code creates a simple web server to monitor port 8080.The root resource of the server is a container resource, which can contain other resources.In this example, we created a FileReSource instance to indicate a static HTML file called index.html.Then add FileReSource to the root resource.Finally, start the server to access the index.html file in the browser.