目录

6、Web原生组件注入（Servlet、Filter、Listener）

6.1、使用Servlet API 注入（Servlet、Filter、Listener）

目录结构

1.Servlet组件注入

2.Filter组件注入

3.Listener组件注入

6.2、使用RegistrationBean 注入（比较简便，只需要在Config配置类中注入即可生效）

6、Web原生组件注入（Servlet、Filter、Listener）

6.1、使用Servlet API 注入（Servlet、Filter、Listener）

目录结构

1.Servlet组件注入

步骤：

1.必须继承 httpServlet

2.要加 @WebServlet(urlpatterns=“/my”) , 注解设置访问路径

3.使用 Servlet API

在Application启动类中添加扫包:

@ServletComponentScan(basePackages = "com.tulingxueyuan.request")

Application启动类，下同1.2.3条

package com.tulingxueyuan.request;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.ServletComponentScan;
//3.对于SpringBoot中使用原生的组件注入，servlet要配置扫描器，@ServletComponentScan(basePackages = "com.tulingxueyuan.request")
@ServletComponentScan(basePackages = "com.tulingxueyuan.request")
@SpringBootApplication
public class Application {

    public static void main(String[] args) {

        SpringApplication.run(Application.class, args);
    }

}

MyServlet.java

package com.tulingxueyuan.request.servlet;

import javax.jws.WebService;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

//1.必须继承httpservlert
//2.要加@WebServlet(urlpatterns="/my"),注解设置访问路径

@WebServlet(urlPatterns = "/my")
public class MyServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.getWriter().write("66666");
    }
}

2.Filter组件注入

步骤：

1.自定义的Filter(过滤器)必须实现，Javax 下Servlet 的 Filter类，然后重写方法。

2.最后在类上标注@WebFilter 注解，另外对于SpringBoot中使用原生的组件注入，servlet要配置扫描器，@ServletComponentScan(basePackages = "com.tulingxueyuan.request")

MyFilter.java

package com.tulingxueyuan.request.servlet;

import javax.jws.WebService;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

//1.必须继承httpservlert
//2.要加@WebServlet(urlpatterns="/my"),注解设置访问路径

@WebServlet(urlPatterns = "/my")
public class MyServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.getWriter().write("66666");
    }
}

3.Listener组件注入

步骤：

1.实现自定义监听器，需要实现 ServletContextListener接口，然后添加@WebListener注解，重写方法，

2.在启动类上配置

@ServletComponentScan(basePackages = “com.tulingxueyuan.request.servlet”)注解，用以扫描包

package com.tulingxueyuan.request.servlet;

import lombok.extern.slf4j.Slf4j;

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

//1.实现自定义监听器，需要实现 ServletContextListener接口，然后添加@WebListener注解，重写方法，
//2.在启动类上配置@ServletComponentScan(basePackages = "com.yan")注解，用以扫描包

@WebListener
@Slf4j
public class MyServletContextListener implements ServletContextListener {
    @Override
    public void contextInitialized(ServletContextEvent sce) {
        log.info("MyServletContextListener监听到项目初始化完成");
    }

    @Override
    public void contextDestroyed(ServletContextEvent sce) {
        log.info("MyServletContextListener监听到项目销毁");
    }
}

6.2、使用RegistrationBean 注入（比较简便，只需要在Config配置类中注入即可生效）

包括下面3个：

1. ServletRegistrationBean
2. FilterRegistrationBean
3. ServletListenerRegistrationBean

package com.tulingxueyuan.request.servlet;

//import jdk.nashorn.internal.objects.NativeReferenceError;
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.ServletContextListener;
import java.util.Arrays;

@Configuration
public class MyRegistrationConfig {
    @Bean
    public ServletRegistrationBean myServlet(){
        MyServlet myServlet = new MyServlet();
        return new ServletRegistrationBean(myServlet,"/my","/my02");
    }
    @Bean
    //Filter拦截器
    public FilterRegistrationBean myFilter(){
        MyFilter myFilter = new MyFilter();
        FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean(myFilter);
        filterRegistrationBean.setUrlPatterns(Arrays.asList("/my","/css/*"));
        //
        return filterRegistrationBean;
    }
    @Bean
    //Listener监听器
    public ServletListenerRegistrationBean myListener(){
        MyServletContextListener myServletContextListener = new MyServletContextListener();
        return new ServletListenerRegistrationBean(myServletContextListener);
    }
}