spring boot配置Servlet容器

Spring boot 默认使用Tomcat做为嵌入式Servlet容器,只须要引入spring-boot-start-web依赖,默认采用的Tomcat做为容器

01  定制和修改Servlet容器的相关配置(ServerProperties是EmbeddedServletContainerCustomizer的子类)

server.port=8080 server.context-path=/ # tomcat相关设置 server.tomcat.uri-encoding=UTF-8

也能够编写EmbeddedServletContainerCustomizer(嵌入式的Servlet容器定制器),来修改servlet容器的配置

@Bean public EmbeddedServletContainerCustomizer embeddedServletContainerCustomizer(){ //定制嵌入式的Servlet容器相关的属性配置 
    return container -> container.setPort(8083); } 

2 注册Servlet容器的三大组件(Servlet  Filter  Listener)

spring boot默认采用是以jar包的形式启动嵌入式的servlet容器,从而启动Springboot的web应用,没有web.xml,固然也能够使用注解的方式(@WebServlet,@WebListener,@WebFilter),如今使用Spring boot做为框架,若是编写三大组件,则须要使用配置的方式进行注册

01 ServletRegistrationBean:注册Servlet

//Servlet定义 
public class MyServlet extends HttpServlet { @Override protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { System.out.println("这是一个servlet请求..."); } } //Servlet注册 
@Configuration public class MyServletConfig { //注册Servlet 
 @Bean public ServletRegistrationBean myServlet(){ return new ServletRegistrationBean(new MyServlet(), "/myServlet"); } } 

 

02 FilterRegistrationBean:注册Filter

//Filter定义 
public class MyFilter implements Filter { @Override public void init(FilterConfig filterConfig) throws ServletException { } @Override public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { System.out.println("MyFilter process..."); //放行 
 chain.doFilter(request, response); } @Override public void destroy() { } } //Filter注册 
@Bean public FilterRegistrationBean myFilter(){ FilterRegistrationBean bean = new FilterRegistrationBean(); bean.setFilter(new MyFilter()); bean.setUrlPatterns(Arrays.asList("/hello", "/myServlet")); return bean; } 

ServletListenerRegistrationBean:注册Listener

//Listener定义 
public class MyListener implements ServletContextListener { @Override public void contextInitialized(ServletContextEvent sce) { System.out.println("contextInitialized...web启动"); } @Override public void contextDestroyed(ServletContextEvent sce) { System.out.println("contextDestroyed...web销毁"); } } //Listener注册 
@Bean public ServletListenerRegistrationBean myListener(){ return new ServletListenerRegistrationBean<>(new MyListener()); } 

最熟悉的是,spring boot 在自动配置springMVC,会自动注册SpringMVC前端控制器:DispatcherServlet,该控制器主要在DispatcherServletAutoConfiguration自动配置类中进行注册

@AutoConfigureOrder(Ordered.HIGHEST_PRECEDENCE) @Configuration @ConditionalOnWebApplication @ConditionalOnClass(DispatcherServlet.class) @AutoConfigureAfter(EmbeddedServletContainerAutoConfiguration.class) public class DispatcherServletAutoConfiguration { //other code... 
      
    public static final String DEFAULT_DISPATCHER_SERVLET_BEAN_NAME = "dispatcherServlet"; private String servletPath = "/"; @Bean(name = DEFAULT_DISPATCHER_SERVLET_REGISTRATION_BEAN_NAME) @ConditionalOnBean(value = DispatcherServlet.class, name = DEFAULT_DISPATCHER_SERVLET_BEAN_NAME) public ServletRegistrationBean dispatcherServletRegistration( DispatcherServlet dispatcherServlet) { ServletRegistrationBean registration = new ServletRegistrationBean( dispatcherServlet, this.serverProperties.getServletMapping()); //默认拦截 / 全部请求，包括静态资源，可是不拦截jsp请求；/*会拦截jsp //能够经过修改server.servlet-path来修改默认的拦截请求 
 registration.setName(DEFAULT_DISPATCHER_SERVLET_BEAN_NAME); registration.setLoadOnStartup( this.webMvcProperties.getServlet().getLoadOnStartup()); if (this.multipartConfig != null) { registration.setMultipartConfig(this.multipartConfig); } return registration; } } 

3 其余Servlet容器

Spring boot默认支持Tomcat,Jetty 和Undertow做为底层容器

而Spring boot默认使用Tomcat,一旦引入spring-boot-starter-web模块,就默认使用Tomcat

切换其其余Servlet容器

  将tomcat依赖移除同事引入其余Servlet容易

引入jetty

<dependency>  
    <groupId>org.springframework.boot</groupId>  
    <artifactId>spring-boot-starter-web</artifactId>  
    <exclusions>  
        <exclusion>  
            <artifactId>spring-boot-starter-tomcat</artifactId>  
            <groupId>org.springframework.boot</groupId>  
        </exclusion>  
    </exclusions>  
</dependency>  
  
<dependency>  
    <groupId>org.springframework.boot</groupId>  
    <artifactId>spring-boot-starter-jetty</artifactId>  
</dependency>

引入undertow

<dependency>  
    <groupId>org.springframework.boot</groupId>  
    <artifactId>spring-boot-starter-web</artifactId>  
    <exclusions>  
        <exclusion>  
            <artifactId>spring-boot-starter-tomcat</artifactId>  
            <groupId>org.springframework.boot</groupId>  
        </exclusion>  
    </exclusions>  
</dependency>  
  
<dependency>  
    <groupId>org.springframework.boot</groupId>  
    <artifactId>spring-boot-starter-jetty</artifactId>  
</dependency>

参考文章   https://blog.csdn.net/caychen/article/details/80344372

这里对于常见的容器jetty和tomcat作一个简单对比

 jetty  更轻量级,更加灵活,可插拔和可扩展,其架构是基于Handler来实现的,能够同时处理大量长时间链接,默认采用NIO,在处理静态资源性能较高

Tomcat  默认采用BIO,基于容器设计的,不易扩展,对JavaEE和Servlet的支持更加全面,不少特性直接集成