springboot随笔五：添加Interceptor，Filter，Servlet, Listener

一：添加拦截器：实现HandlerInterceptor接口，并在由配置类(有@Configuration注解)加入该interceptor，并设置拦截路径

package com.wzp.interceptor;

import com.wzp.domain.User;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class LoginHandlerInterceptor implements HandlerInterceptor {

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("intercept url:" + request.getRequestURL());
        System.out.println("intercept uri:" + request.getRequestURI());
        User user = (User) request.getSession().getAttribute("user");
        if (null != user) {
            return true;
        }
        request.setAttribute("flag", "error");
        request.getRequestDispatcher("/login").forward(request, response);
        return false;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {

    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {

    }
}

 

 

package com.wzp.config;

import com.wzp.interceptor.LoginHandlerInterceptor;
import com.wzp.resolver.MyLocaleResolver;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.LocaleResolver;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Configuration
//@EnableWebMvc// 如果配置了这个，springboot的webMvc将不会自动装配，也就是说springboot给我们的默认很多web功能将失效，完全有自己接管
public class MyConfig implements WebMvcConfigurer {// 通过实现WebMvcConfigurer来在原来springboot自动化的基础上进行扩展
    
    // 添加拦截器
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        // 除了去登录页面，其他请求全部拦截
        registry.addInterceptor(new LoginHandlerInterceptor()).addPathPatterns("/**").excludePathPatterns("/", "/index", "/index.html", "/", "/login", "/login.html", "/user/login",
                "/images/*", "/webjars/**");
    }

    
}

 

 

二：添加Servlet, Filter, Listener

package com.wzp;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class MyServelt extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doPost(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        System.out.println("myServlet *********************");
    }


}

package com.wzp.filter;

import javax.servlet.*;
import java.io.IOException;

public class MyFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        System.out.println("myFilter *************");
        filterChain.doFilter(servletRequest, servletResponse);
    }

    @Override
    public void destroy() {

    }
}

package com.wzp.listener;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

public class MyListener implements ServletContextListener {

    @Override
    public void contextInitialized(ServletContextEvent sce) {
        System.out.println("web 应用启动");
    }

    @Override
    public void contextDestroyed(ServletContextEvent sce) {
        System.out.println("web 结束");
    }
}

package com.wzp.config;

import com.wzp.MyServelt;
import com.wzp.filter.MyFilter;
import com.wzp.listener.MyListener;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.boot.web.servlet.ServletListenerRegistrationBean;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import javax.servlet.Filter;
import javax.servlet.Servlet;
import java.util.Arrays;

/**
 * 与服务器相关的配置
 */

@Configuration
public class MyServerConfig {

    @Bean
    public ServletRegistrationBean myServlet() {
        ServletRegistrationBean<Servlet> servletServletRegistrationBean = new ServletRegistrationBean<Servlet>(new MyServelt(), "/myServlet");
        return servletServletRegistrationBean;
    }

    @Bean
    public FilterRegistrationBean myFilter() {
        FilterRegistrationBean<Filter> filterFilterRegistrationBean = new FilterRegistrationBean<Filter>();
        filterFilterRegistrationBean.setFilter(new MyFilter());
        filterFilterRegistrationBean.setUrlPatterns(Arrays.asList("/myServlet"));
        return filterFilterRegistrationBean;
    }

    @Bean
    public ServletListenerRegistrationBean myListener() {
        ServletListenerRegistrationBean registrationBean = new ServletListenerRegistrationBean();
        registrationBean.setListener(new MyListener());
        return registrationBean;
    }
}