Spring Boot：
SpringBoot-start-web 里面依赖的环境中
如果是外部的Tomcat 容器，可以通过修改config进行配置
内嵌的呢？
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类【也是EmbeddedServletContainerCustomizer】）；
经常用的：
server.port=8081
server.context‐path=/crud
server.tomcat.uri‐encoding=UTF‐8
//通用的Servlet容器设置 server.xxx //Tomcat的设置 server.tomcat.xxx 最大连接数等等
原理：
@ConfigurationProperties(prefix = "server", ignoreUnknownFields = true)
public class ServerProperties { /**
* Server HTTP port.
*/
private Integer port; /**
* Network address to which the server should bind.
*/
private InetAddress address; @NestedConfigurationProperty
private final ErrorProperties error = new ErrorProperties(); /**
* Whether X-Forwarded-* headers should be applied to the HttpRequest.
*/
private Boolean useForwardHeaders; /**
* Value to use for the Server response header (if empty, no header is sent).
*/
private String serverHeader; /**
* Maximum size of the HTTP message header.
*/
private DataSize maxHttpHeaderSize = DataSize.ofKilobytes(8); /**
* Time that connectors wait for another HTTP request before closing the connection.
* When not set, the connector's container-specific default is used. Use a value of -1
* to indicate no (that is, an infinite) timeout.
*/
private Duration connectionTimeout; @NestedConfigurationProperty
private Ssl ssl; @NestedConfigurationProperty
private final Compression compression = new Compression(); @NestedConfigurationProperty
private final Http2 http2 = new Http2(); private final Servlet servlet = new Servlet(); private final Tomcat tomcat = new Tomcat(); private final Jetty jetty = new Jetty(); private final Undertow undertow = new Undertow(); public Integer getPort() {
return this.port;
} public void setPort(Integer port) {
this.port = port;
} public InetAddress getAddress() {
return this.address;
}
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 （已经过时了）
@Bean //一定要将这个定制器加入到容器中
public EmbeddedServletContainerCustomizer embeddedServletContainerCustomizer(){
return new EmbeddedServletContainerCustomizer() {
//定制嵌入式的Servlet容器相关的规则
@Override
public void customize(ConfigurableEmbeddedServletContainer container) {
container.setPort(8083);
}
};
}
注册Servlet的三大组件 Servlet Filter Listener
Spring boot 默认以jar包的方式 启动嵌入式tomcat，而不是标准的web应用。 webapp/WEB-INF/web.xml
没有web.xml 也可以注册哦
ServletRegistrationBean
//注册三大组件
@Bean
public ServletRegistrationBean myServlet(){
ServletRegistrationBean registrationBean = new ServletRegistrationBean(new
MyServlet(),"/myServlet");
return registrationBean;
}
举个栗子：
MyServlet:
public class MyServlet extends HttpServlet {
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doPost(req, resp);
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
resp.getWriter().write("hello MyServlet");
}
}
config:
@Configuration
public class MyConfig { @Bean
public ServletRegistrationBean<Servlet> myServlet(){ //是个class 直接new出来
ServletRegistrationBean<Servlet> servletServletRegistrationBean =
new ServletRegistrationBean<>(new MyServlet(),"/myServlet");
return servletServletRegistrationBean;
}
}
运行后：注册成功
FilterRegistrationBean
@Bean
public FilterRegistrationBean myFilter(){
FilterRegistrationBean registrationBean = new FilterRegistrationBean();
registrationBean.setFilter(new MyFilter());
registrationBean.setUrlPatterns(Arrays.asList("/hello","/myServlet"));
return registrationBean;
}
举个栗子：
config中加入组件：
@Bean
public FilterRegistrationBean myFilter(){
FilterRegistrationBean<Filter> filterFilterRegistrationBean = new FilterRegistrationBean<>();
filterFilterRegistrationBean.setFilter(new MyFilter());
filterFilterRegistrationBean.setUrlPatterns(Arrays.asList("/hello","/myServlet"));
return filterFilterRegistrationBean;
}
过滤器：
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("doFilter 方法執行");
filterChain.doFilter(servletRequest,servletResponse);
}
@Override
public void destroy() {
}
}
请求后：
ServletListenerRegistrationBean
@Bean
public ServletListenerRegistrationBean myListener(){
ServletListenerRegistrationBean<MyListener> registrationBean = new
ServletListenerRegistrationBean<>(new MyListener());
return registrationBean;
}
举个栗子：
/**
* listener 有好多的！
*/
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..................");
}
}
组件注册进去：
@Bean
public ServletListenerRegistrationBean myListener(){
ServletListenerRegistrationBean<MyListener> registrationBean = new ServletListenerRegistrationBean<>(
new MyListener()); //通過構造函數 s
return registrationBean;
}
启动和退出
总结：
Spring boot 帮我们自动配置Spring mvc的时候，自动注册了前端控制器，DispatcherServlet。 （DispatcherServletAutoConfiguration类）
这个类中有个方法：
@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： / 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(DEFAULT_DISPATCHER_SERVLET_BEAN_NAME);
registration.setLoadOnStartup(
this.webMvcProperties.getServlet().getLoadOnStartup());
if (this.multipartConfig != null) {
registration.setMultipartConfig(this.multipartConfig);
}
return registration;
}
总结一个思路：
经常在看源码时候，发现定义一个接口，然后实现类是个中Factory命名的。通过某个工厂创建组件 xxFactory 是用來得到xx的！
condition的用法，倒入哪個，那個生效。