Spring Boot 学习（一） 原生组件注入

1.使用Servlet  API

@ServletComponentScan(basePackages = "com.sp")      //可以自动将写的servlet扫描进去  配置扫描的包，在BootWeb01Application里面声明注解

@WebServlet(urlPatterns = "/my")    //这注解是servlet3.0生成的注解，在Myservlet里声明注解 ,直接响应没有结果spring boot的拦截器

@WebFilter(urlPatterns = {"/css/*","/js/*","/imges/*"})    //可以拦截请求,css下的所有、js下的所有、imges下的所有请求

@WebListener

Servlet
@WebServlet(urlPatterns = "/my")    //这注解是servlet3.0生成的注解
public class Myservlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.getWriter().write("123456");
    }
}

Filter
package com.sp.filter;


import lombok.extern.slf4j.Slf4j;

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

@Slf4j
@WebFilter(urlPatterns = {"/css/*","/js/*","/imges/*"})    //指定路径拦截，拦截成功会打印MyFilter工作
public class Myfilter implements Filter {

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        log.info("Myfilter初始化完成");
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        log.info("Myfilter工作");
//        Filter想要进行过滤，要在Filter链中
        chain.doFilter(request,response);
    }

    @Override
    public void destroy() {
        log.info("Myfilter销毁");
    }
}

Listener
package com.sp.servlet;


import lombok.extern.slf4j.Slf4j;

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

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

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

 

 

 

 

 

 

 

 2.使用方法二、使用RegistrationBean

springboot中的拦截方法

注意要先声明为Configration配置类，之后通过添加容器的方式进行配置Servlet，只要配置了请求的Url才会在控制台显示提示信息

package com.sp.servlet;


import com.sp.filter.Myfilter;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.util.Arrays;

@Configuration    //声明为配置类   这里没有声明ProxyBeanMethods = false 
　　　　　　　//　因为false会导致不是单实例，每次new都会新建一个，会导致对象的冗余
　　　　　　　//　默认为true

public class MyRegistConfig {

    @Bean     //存放到容器中
    public ServletRegistrationBean myServlet() {
        Myservlet myservlet = new Myservlet();

        return new ServletRegistrationBean(myservlet,"/my01","/my02");  //可以放多个servlet请求
    }
    @Bean
    public FilterRegistrationBean myFilter() {
        Myfilter myfilter = new Myfilter();

//        return new FilterRegistrationBean(myfilter,myServlet() );    //访问servlet的指定路径
        FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean(myfilter);  
        filterRegistrationBean.setUrlPatterns(Arrays.asList("/my04","/my05"));　　　//自定义访问路径

return filterRegistrationBean; } }

 

 

 

@Bean     //存放到容器中
    public ServletRegistrationBean myServlet() {
        Myservlet myservlet = new Myservlet();

        return new ServletRegistrationBean(myservlet,"/my01","/my02","/my04");  //可以放多个servlet请求
    }
    @Bean
    public FilterRegistrationBean myFilter() {
        Myfilter myfilter = new Myfilter();

//        return new FilterRegistrationBean(myfilter,myServlet() );  //访问servlet的指定路径
        FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean(myfilter);
        filterRegistrationBean.setUrlPatterns(Arrays.asList("/my04","/my05"));    //此时自定义拦截，其中my04是servlet定义的请求，所以可以返回123456
        return filterRegistrationBean;
    }

 

 

 

监听器,在启动时打印写入的内容

 

 @Bean
    public ServletListenerRegistrationBean myListener() {
        MyservletListener myservletListener = new MyservletListener();
        return  new ServletListenerRegistrationBean(myservletListener);
    }

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

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

 

 

 

 

*单星是servlet的写法   **双星是spring的写法

 

注意：配置静态资源路径的时候：可以用数组来表示多个静态资源路径

resources:
  static-locations: [classpath:/templates,classpath:/static,classpath:/public]