spring boot 配置过滤器filter, 拦截器interceptor, 监听器listener

简单配置,如需深入学习和使用, 待续

项目地址码云

1. filter过滤器

过滤器是servlet提供, 用于对servlet的请求和详情进行过滤处理

import org.springframework.boot.web.servlet.ServletComponentScan;
import org.springframework.stereotype.Component;

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

/**
 * spring boot 注解式过滤器,
 *  1. 定义一个类实现javax.servlet.annotation.WebFilter.Filter接口,并重写三大方法
 *          通常: init和destroy可以不用重写
 *          主要重写doFilter方法
 *  2. 使用注解@WebFilter(urlPatterns = "/*", filterName = "indexFilter")
 *          来定义这是一个拦截器, urlPatterns是拦截规则, filterName是拦截器名称
 *  3. 启动类上增加注解@ServletComponentScan, 启动即可,
 *
 * 拦截规则: urlPatterns = {"/*", "*.html", "/filter/test1/*"}
 *          分别对应: 所有请求, 以.html为后缀的所有请求, 指定路径的所有请求
 *
 * Created by noseew on 2018/1/5.
 */
/**
 * 注解方式配置filter需要@Component,@ServletComponentScan 或者将@ServletComponentScan加在启动类上
 */
//@Component
@ServletComponentScan
@WebFilter(urlPatterns = {"/*", "*.html", "/filter/test1/*"}, filterName = "indexFilter")
public class IndexFilter implements Filter {

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        System.out.println("filter init...");
    }

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

        /**
         * 这里进行请求和相应的过滤处理
         */

        // filter chain filter过滤链
        filterChain.doFilter(servletRequest, servletResponse);
    }

    @Override
    public void destroy() {
        System.out.println("filter destroy...");
    }
}

2. interceptor拦截器

拦截器有spring框架提供, 和过滤器功能相似,拦截器能实现过滤器的基本功能, 此外能对请求响应页面等实现精确拦截控制, 个人觉得在前后端分离的项目中使用不多.

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

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

/**
 * spring boot 自定义拦截器
 *
 * Created by noseew on 2018/1/5.
 */

public class IndexInterceptor implements HandlerInterceptor {

    private static final Logger logger = LoggerFactory.getLogger(IndexInterceptor.class);

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse httpServletResponse, Object o) throws Exception {
        /**
         * 对来自后台的请求统一进行日志处理
         */
        String url = request.getRequestURL().toString();
        String method = request.getMethod();
        String uri = request.getRequestURI();
        String queryString = request.getQueryString();
        System.out.println(request.getParameterMap());
        logger.info(String.format("请求参数, url: %s, method: %s, uri: %s, params: %s", url, method, uri, queryString));
        System.out.println("在请求处理之前进行调用（Controller方法调用之前）");
        return true;// 只有返回true才会继续向下执行，返回false取消当前请求
    }

    @Override
    public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {
        System.out.println("请求处理之后进行调用，但是在视图被渲染之前（Controller方法调用之后）");
    }

    @Override
    public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {
        System.out.println("在整个请求结束之后被调用，也就是在DispatcherServlet 渲染了对应的视图之后执行（主要是用于进行资源清理工作）");
    }
}

import org.song.servlet.config.interceptors.IndexInterceptor;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

/**
 * java配置方式, 配置interceptor 拦截器
 *
 * Created by noseew on 2018/1/5.
 */

@Configuration
public class IndexInterceptorConfig extends WebMvcConfigurerAdapter {

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        // 多个拦截器组成一个拦截器链
        // addPathPatterns 用于添加拦截规则
        // excludePathPatterns 用户排除拦截
        registry.addInterceptor(new IndexInterceptor()).addPathPatterns("/**").excludePathPatterns("/*");

        super.addInterceptors(registry);
    }
}

3. listener监听器

监听器listener, 个人使用不多, 主要对服务的事件进行监听,这里仅作参考

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.servlet.annotation.WebListener;

/**
 * 自定义监听器配置
 *
 * 实现ServletContextListener并重写方法
 *
 * Created by noseew on 2018/1/6.
 */
/**
 * 可以配合 @[email protected] 放在自定义监听器上
 * 也可以方在启动类上
 * 但是不能同时使用多个
 * 也可以单独放@ServletComponentScan在启动类上, 可以配置多个监听器
 *
 */
//@Component
//@ServletComponentScan
@WebListener
public class ListenerServletContent implements ServletContextListener {

    @Override
    public void contextInitialized(ServletContextEvent servletContextEvent) {
        System.out.println("ListenerServletContent init...");
    }

    @Override
    public void contextDestroyed(ServletContextEvent servletContextEvent) {
        System.out.println("ListenerServletContent destroy...");
    }
}