一.需求
Web 开发使用 Controller 基本上可以完成大部分需求，但是我们还可能会用到 Servlet、 FilterListene
二、案例
2.1
通过注册 ServletRegistrationBean、 FilterRegistrationBean 和ServletListenerRegistrationBean 获得
package com.shyroke;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
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 util.MyFilter;
import util.MyListener;
import util.MyServlet;
@SpringBootApplication
public class Springboot01Application {
@Bean
public ServletRegistrationBean servletRegistrationBean() {
return new ServletRegistrationBean(new MyServlet(), "/servlet");
}
@Bean
public FilterRegistrationBean filterRegistrationBean() {
return new FilterRegistrationBean(new MyFilter(), servletRegistrationBean());
}
@Bean
public ServletListenerRegistrationBean<MyListener> listenerRegistrationBean(){
return new ServletListenerRegistrationBean<MyListener>(new MyListener());
}
public static void main(String[] args) {
SpringApplication.run(Springboot01Application.class, args);
}
}
2.2 MyServlet.java
package util;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class MyServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
this.doPost(req, resp);
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
System.out.println("我是servlet");
resp.getWriter().write("hello world servlet");
}
}
2.3 MyFilter.java
package util;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
public class MyFilter implements Filter {
@Override
public void init(FilterConfig filterConfig) throws ServletException {
// TODO Auto-generated method stub
}
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
throws IOException, ServletException {
System.out.println("我是filter");
chain.doFilter(request, response);
}
@Override
public void destroy() {
// TODO Auto-generated method stub
}
}
2.4 MyListener.java
package util;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
public class MyListener implements ServletContextListener{
@Override
public void contextInitialized(ServletContextEvent sce) {
System.out.println("contextInitialized");
}
@Override
public void contextDestroyed(ServletContextEvent sce) {
System.out.println("contextDestroyed");
}
}
2.5 结果
说明servlet生效
filter和listener生效