SpringBoot修改servlet容器配置、注册三大组件、切换servlet容器

待我称王封你为后i 2022-12-27 12:34 129阅读 0赞

# 一、修改Servlet容器配置 #

**Springboot默认servlet容器是Tomcat**  
![默认tomcat][tomcat]

## 1、通过yaml修改 ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQzNDQyMzM1_size_16_color_FFFFFF_t_70]  
绑定的是ServerProperties配置类  
**注意，这里通过配置类修改的容器设置会覆盖掉yaml的，也就是说配置类的优先级高于yaml，亲测**  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQzNDQyMzM1_size_16_color_FFFFFF_t_70 1]

## 2、编写WebServerFactoryCustomizer配置方法 ##

通过serlvet工厂类来修改容器配置  
`WebServerFactoryCustomizer`：

@Bean
        public WebServerFactoryCustomizer<ConfigurableWebServerFactory> webServerFactoryCustomizer(){ 
            return new WebServerFactoryCustomizer<ConfigurableWebServerFactory>(){ 
                @Override
                public void customize(ConfigurableWebServerFactory factory) { 
                    factory.setPort(8081);
                }
            };
        }

# 二、注册三大组件 #

## 1、注册Servlet ##

首先编写一个`servlet`  
`MyServlet`：

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

在配置类中注入`bean`  
`ServletRegistrationBean` ：

@Bean
        public ServletRegistrationBean myServlet(){ 
            return new ServletRegistrationBean(new MyServlet(),"/myServlet");
        }

`Springboot`自动装配的`SpringMVC`中的`DispatcherServlet`也是通过`RegistrationBean`进行自动配置

`DispatcherServletRegistrationConfiguration`：

@Configuration(proxyBeanMethods = false)
    	@Conditional(DispatcherServletRegistrationCondition.class)
    	@ConditionalOnClass(ServletRegistration.class)
    	@EnableConfigurationProperties(WebMvcProperties.class)
    	@Import(DispatcherServletConfiguration.class)
    	protected static class DispatcherServletRegistrationConfiguration { 
    
    		@Bean(name = DEFAULT_DISPATCHER_SERVLET_REGISTRATION_BEAN_NAME)
    		@ConditionalOnBean(value = DispatcherServlet.class, name = DEFAULT_DISPATCHER_SERVLET_BEAN_NAME)
    		public DispatcherServletRegistrationBean dispatcherServletRegistration(DispatcherServlet dispatcherServlet,
    				WebMvcProperties webMvcProperties, ObjectProvider<MultipartConfigElement> multipartConfig) { 
    			DispatcherServletRegistrationBean registration = new DispatcherServletRegistrationBean(dispatcherServlet,
    					webMvcProperties.getServlet().getPath());
    			registration.setName(DEFAULT_DISPATCHER_SERVLET_BEAN_NAME);
    			registration.setLoadOnStartup(webMvcProperties.getServlet().getLoadOnStartup());
    			multipartConfig.ifAvailable(registration::setMultipartConfig);
    			return registration;
    		}
    
    	}

默认的`path`：`private String path = "/";`

## 2、注册Filter ##

编写一个`Filter`：

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

通过配置类注入Bean：

@Bean
        public FilterRegistrationBean myFilter(){ 
            FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean();
            filterRegistrationBean.setFilter(new MyFilter());
            filterRegistrationBean.setUrlPatterns(Arrays.asList("/myServlet","/filter"));
            return filterRegistrationBean;
        }

## 3、注册Litener ##

编写一个Litener：

public class MyListener implements ServletContextListener { 
        public void contextInitialized(ServletContextEvent sce) { 
            System.out.println("web init");
        }
    
        public void contextDestroyed(ServletContextEvent sce) { 
            System.out.println("web destroy");
        }
    }

通过配置类注入Bean：

@Bean
        public ServletListenerRegistrationBean myListener(){ 
            ServletListenerRegistrationBean listenerRegistrationBean = new ServletListenerRegistrationBean(new MyListener());
            return listenerRegistrationBean;
        }

# 三、切换其他Serlvet容器 #

在pom中排除spring-boot-starter-tomcat，并且加入jetty的启动器

<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>
                <artifactId>spring-boot-starter-jetty</artifactId>
                <groupId>org.springframework.boot</groupId>
            </dependency>

![jetty][]

[tomcat]: /images/20221120/af779bea48494b2f8283e8b012891dac.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQzNDQyMzM1_size_16_color_FFFFFF_t_70]: /images/20221120/54835297b0ed480b9cbab7d385b3a73b.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQzNDQyMzM1_size_16_color_FFFFFF_t_70 1]: /images/20221120/5767c296e2034db89052a477d3b283c7.png
[jetty]: /images/20221120/027d6d45a0784b2699b00f0d721c9c67.png