Spring MVC Handler拦截器用例

Spring MVC HandlerInterceptor Example

HandlerInterceptor 接口有三个方法:

preHandle(): It is executed before actual handler is executed. 在实际处理之前执行, 返回值是布尔类型, false 取消处理
postHandle(): It is executed after handler is executed. 在实际处理之后执行
afterCompletion(): It is executed after the complete request is finished.  在完成请求后执行

import ...@EnableMvc
@ComponetScan(basePackageClasses = { Index.class })
public final class MyWebAppInitializer extends WebConfigAdapter {@Overridepublic void addInterceptors(InterceptorRegistry registry) {registry.addInterceptor( new HandlerInterceptorAdapter() {@Overridepublic boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {return true; // 继续处理}}).addPathPatterns("/*", "/*.jpg");//}...
}

如果不调用 addPathPatterns( String... ) , 则会匹配所有 RequestMapping

Spring 过滤器用例

javax.servlet
Interface Filter
All Known Implementing Classes:
GenericFilter, HttpFilter

default void    destroy()
//Called by the web container to indicate to a filter that it is being taken out of service.void    doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
//The doFilter method of the Filter is called by the container each time a request/response pair is passed through the chain due to a client request for a resource at the end of the chain.default void    init(FilterConfig filterConfig)
//Called by the web container to indicate to a filter that it is being placed into service.

实现效果:

package club.init;import java.io.IOException;
import java.util.Enumeration;import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;public class StaticResourceFilter implements Filter {@Overridepublic void init(FilterConfig filterConfig) throws ServletException {}@Overridepublic void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) {intercept((HttpServletRequest)request, (HttpServletResponse)response, chain);}public void intercept(HttpServletRequest request, HttpServletResponse response, FilterChain chain) {// 添加服务器名try {response.addHeader("Server", "Fast Tomcat");} catch (Exception e) {e.printStackTrace();}// 获取 referEnumeration<String> headers = request.getHeaderNames();String refer = null;String content = "GET " + request.getRequestURI() + "\n";while (headers.hasMoreElements()) {String header = headers.nextElement();content += String.format("%s : %s\n", header, request.getHeader(header));if ("referer".equals(header)) {refer = request.getHeader(header);break;}}Log.d(content);if (request.getRequestURI().matches(".*\\..+")) {// 静态资源if (refer == null || !refer.matches("https?://abc.com/.*")) {response.setStatus(404);response.addHeader("Error", "You can't use this resource without abc.com");return;}response.addHeader("Content-Disposition", String.format("attachment; filename*=UTF-8''%s", request.getRequestURI().replaceAll(".*/", "")));}try {chain.doFilter(request, response);} catch (IOException | ServletException e) {e.printStackTrace();}}}

最好使用 HttpFilter 这个类

这里有一个使用过滤器的项目: https://github.com/develon2015/Spring-filter