spring mvc —— servlet Filter 过滤器实现控制层 2

╰半夏微凉° 2022-06-02 04:41 213阅读 0赞

@WebFilter(filterName = "DispatcherFilter",
            urlPatterns = { "/*" })
    public class DispatcherFilter implements Filter {
    
    
        @Override
        public void init(FilterConfig filterConfig)
                throws ServletException {
        }
    
    
        @Override
        public void destroy() {
        }
    
    
        @Override
        public void doFilter(ServletRequest request,
                ServletResponse response, FilterChain filterChain)
                throws IOException, ServletException {
            HttpServletRequest req = (HttpServletRequest) request;
            String uri = req.getRequestURI();
            /*
             * uri is in this form: /contextName/resourceName, for
             * example /appdesign2/input-product. However, in the
             * case of a default context, the context name is empty,
             * and uri has this form /resourceName, e.g.:
             * /input-product
             */
            // action processing
            int lastIndex = uri.lastIndexOf("/");
            String action = uri.substring(lastIndex + 1);
            String dispatchUrl = null;
            if ("input-product".equals(action)) {
                // do nothing
                dispatchUrl = "/jsp/ProductForm.jsp";
            } else if ("save-product".equals(action)) {
                // create form
                ProductForm productForm = new ProductForm();
                // populate action properties
                productForm.setName(request.getParameter("name"));
                productForm.setDescription(
                        request.getParameter("description"));
                productForm.setPrice(request.getParameter("price"));
                
                // create model
                Product product = new Product();
                product.setName(productForm.getName());
                product.setDescription(product.getDescription());
                try {
                    product.setPrice(new BigDecimal(productForm.getPrice()));
                } catch (NumberFormatException e) {
                }
                // execute action method
                SaveProductAction saveProductAction = 
                        new SaveProductAction();
                saveProductAction.save(product);
                
                // store model in a scope variable for the view
                request.setAttribute("product", product);
                dispatchUrl = "/jsp/ProductDetails.jsp";
            }
            // forward to a view
            if (dispatchUrl != null) {
                RequestDispatcher rd = request
                        .getRequestDispatcher(dispatchUrl);
                rd.forward(request, response);
            } else {
                // let static contents pass
                filterChain.doFilter(request, response);
            }
        }
    }

pom

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    	<modelVersion>4.0.0</modelVersion>
    	<groupId>appdesign2</groupId>
    	<artifactId>appdesign2</artifactId>
    	<version>0.0.1-SNAPSHOT</version>
    	<packaging>war</packaging>
    	<build>
    		<plugins>
    			<plugin>
    				<groupId>org.apache.maven.plugins</groupId>
    				<artifactId>maven-war-plugin</artifactId>
    				<version>2.6</version>
    				<configuration>
    					<failOnMissingWebXml>false</failOnMissingWebXml>
    				</configuration>
    			</plugin>
    		</plugins>
    	</build>
    	<dependencies>
    		<dependency>
    			<groupId>javax.servlet</groupId>
    			<artifactId>javax.servlet-api</artifactId>
    			<version>3.1.0</version>
    			<scope>provided</scope>
    		</dependency>
    	</dependencies>
    	<properties>
    		<maven.compiler.source>1.8</maven.compiler.source>
    	</properties>
    </project>

源码 ：  [https://github.com/kaifengxu/spring-mvc-xuexizhinan/tree/master/chapter-02/sts/appdesign2][https_github.com_kaifengxu_spring-mvc-xuexizhinan_tree_master_chapter-02_sts_appdesign2]

[https_github.com_kaifengxu_spring-mvc-xuexizhinan_tree_master_chapter-02_sts_appdesign2]: https://github.com/kaifengxu/spring-mvc-xuexizhinan/tree/master/chapter-02/sts/appdesign2