一、通过配置bean来实现
1.servlet
/**
* 自定义 servlet *
public class CustomServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("servlet get method");
doPost(request, response);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("servlet post method");
response.getWriter().write("hello world");
} }
注册自定义servlet
@ServletComponentScan
@SpringBootApplication
public class SpringBootDemo61Application {
//注册servley ,访问路径为/rencoo
@Bean
public ServletRegistrationBean servletRegistrationBean(){
return new ServletRegistrationBean(new CustomServlet(),"/rencoo");
}
public static void main(String[] args) {
SpringApplication.run(SpringBootDemo61Application.class, args);
}
}
2.filter
/**
* 自定义 filter **/
public class CustomFilter implements Filter {
@Override
public void init(FilterConfig filterConfig) throws ServletException {
System.out.println("init filter");
}
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
throws IOException, ServletException {
System.out.println("do filter");
chain.doFilter(request, response);
}
@Override
public void destroy() {
System.out.println("destroy filter");
}
}
注册自定义filter
@Bean
public FilterRegistrationBean registrationBean(){
return new FilterRegistrationBean(new CustomFilter(),servletRegistrationBean());
//servletRegistrationBean() 意思只拦截servlet,不写则全部拦截
}
3.listener
/**
* 自定义 listener *
* @author wujing */
public class CustomListener implements ServletContextListener {
@Override
public void contextInitialized(ServletContextEvent sce) {
System.out.println("contextInitialized");
}
@Override
public void contextDestroyed(ServletContextEvent sce) {
System.out.println("contextDestroyed");
}
}
//注册
@Bean
public ServletListenerRegistrationBean<CustomListener> listenerRegistrationBean(){
return new ServletListenerRegistrationBean<CustomListener>(new CustomListener());
}
二、通过实现 ServletContextInitializer 接口直接注册
@ServletComponentScan
@SpringBootApplication
public class SpringBootDemo61Application implements ServletContextInitializer {
@Override
public void onStartup(ServletContext servletContext) throws ServletException {
servletContext.addServlet("customServlet", new CustomServlet()).addMapping("/roncoo");
servletContext.addFilter("customFilter", new CustomFilter())
.addMappingForServletNames(EnumSet.of(DispatcherType.REQUEST), true, "customServlet");
servletContext.addListener(new CustomListener()); }
public static void main(String[] args) {
SpringApplication.run(SpringBootDemo61Application.class, args);
}
}
三、在 SpringBootApplication 上使用@ServletComponentScan 注解后,直接通过@WebServlet、 @WebFilter、@WebListener 注解自动注册
@WebServlet(urlPatterns = "/roncoo",name="customServlet")
@WebFilter(urlPatterns = "/*")
@WebListener