17、配置嵌入式servlet容器（1）

SpringBoot默认使用Tomcat作为嵌入式的Servlet容器

1）、如何定制和修改Servlet容器的相关配置

        1、修改和server有关的配置

           （ServerProperties【也是EmbeddedServletContainerCustomizer】）

server.port=
server.servlet.context-path=/crud

//通用的Servlet容器设置
server.xxx

//Tomcat的设置
server.tomcat.xxx
server.tomcat.uri-encoding=UTF-

        2、编写一个EmbeddedServletContainerCustomizer：

            嵌入式的Servlet容器的定制器；来修改Servlet容器的配置

 

         在Spring Boot2.0以上配置嵌入式Servlet容器时

         EmbeddedServletContainerCustomizer类不存在，

         经网络查询发现被WebServerFactoryCustomizer替代

@Configuration
public class config  {
    @Bean
    public WebServerFactoryCustomizer webServerFactoryCustomizer(){
        return new WebServerFactoryCustomizer<ConfigurableServletWebServerFactory >() {

            //定制嵌入式的Servlet容器相关的规则
            @Override
            public void customize(ConfigurableServletWebServerFactory factory) {
                factory.setPort();
            }
        };
    }
}

2）、注册Servlet、Filter、Listener

由于SpringBoot默认是以jar包的方式启动嵌入式的Servlet容器来启动

SpringBoot的web应用，没有web.xml文件

 

使用一下三个类：

ServletRegistrationBean

FilterRegistrationBean

ServletListenerRegistrationBean

注册Servlet

Servlet实现类：

public class MyServlet extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
       resp.getWriter().write("hello");
    }
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
       doPost(req,resp);
    }
}

 

ServletRegistrationBean实现Servl加入容器

@Configuration
public class MyServletConfig {
    //注册三大组件
    @Bean
    public ServletRegistrationBean servletRegistrationBean(){
        // public ServletRegistrationBean(T servlet, String... urlMappings)
        ServletRegistrationBean re = new ServletRegistrationBean(new MyServlet(),"/myServlet");
        return  re;
    }
}

/myServlet、是拦截浏览器的请求

 注册Filter

public class MyFilter implements Filter {
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        System.out.println("MyFilter...");
        filterChain.doFilter(servletRequest,servletResponse);
    }
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
    }
    @Override
    public void destroy() {
    }
}

将Filter添加到容器

@Configuration
public class MyServletConfig {
    //注册Filter
    @Bean
    public FilterRegistrationBean filterRegistrationBean(){
      //  public FilterRegistrationBean(T filter, ServletRegistrationBean... servletRegistrationBeans)
        FilterRegistrationBean f = new FilterRegistrationBean();
        f.setFilter(new MyFilter());
        f.setUrlPatterns(Arrays.asList("/myfilter","/test"));
        return f;
    }
}

Listener：

public class MyListener implements ServletContextListener {
    //监听当前web项目销毁
    @Override
    public void contextDestroyed(ServletContextEvent sce) {
        System.out.println("web  end....");
    }
    //启动监听
    @Override
    public void contextInitialized(ServletContextEvent sce) {

        System.out.println("web  start...");
    }
}

加入容器　　

@Configuration
public class MyServletConfig {
    //注册Listener
    @Bean
    public ServletListenerRegistrationBean servletListenerRegistrationBean(){
        ServletListenerRegistrationBean<MyListener> L = new
            ServletListenerRegistrationBean<MyListener>(new MyListener());
        return L;
    }
}

同时可以设置的参数很多如load-starton......

SpringBoot帮我们自动SpringMVC的时候，自动的注册SpringMVC的前端控制器；

DIspatcherServlet；DispatcherServletAutoConfiguration中：

@Bean(
    name = {"dispatcherServletRegistration"}
)
@ConditionalOnBean(
    value = {DispatcherServlet.class},
    name = {"dispatcherServlet"}
)
public DispatcherServletRegistrationBean dispatcherServletRegistration(DispatcherServlet dispatcherServlet) {
    DispatcherServletRegistrationBean registration = new DispatcherServletRegistrationBean(dispatcherServlet, this.webMvcProperties.getServlet().getPath());
//默认拦截： / 所有请求；包静态资源，但是不拦截jsp请求
//   /*会拦截jsp
//可以通过server.servletPath来修改SpringMVC前端控制器默认拦截的请求路径

 registration.setName("dispatcherServlet");
    registration.setLoadOnStartup(this.webMvcProperties.getServlet().getLoadOnStartup());
    if (this.multipartConfig != null) {
        registration.setMultipartConfig(this.multipartConfig);
    }

    return registration;
}

getPath->WebMvcProperties ->  private String path = "/";