Listener、Filter、Servlet 初始化

来源：互联网发布：pcb开料软件编辑：程序博客网时间：2024/06/07 01:20

listener、Filter、Servlet都有一个初始化的过程
那么它们的初始化顺序是: listener > Filter > Servlet;

servlet初始化

import java.io.IOException;import javax.servlet.Filter;import javax.servlet.FilterChain;import javax.servlet.FilterConfig;import javax.servlet.ServletException;import javax.servlet.ServletRequest;import javax.servlet.ServletResponse;public class TestFilter implements Filter{    public void init(FilterConfig filterConfig) throws ServletException {          System.out.println("Filter 初始化。。。");      }      public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {          System.out.println("doFilter 。。。");          chain.doFilter(request, response);      }      public void destroy() {          System.out.println("Filter 销毁。。。");      } }

filter初始化

import java.io.IOException;import javax.servlet.Filter;import javax.servlet.FilterChain;import javax.servlet.FilterConfig;import javax.servlet.ServletException;import javax.servlet.ServletRequest;import javax.servlet.ServletResponse;public class TestFilter implements Filter{    public void init(FilterConfig filterConfig) throws ServletException {          System.out.println("Filter 初始化。。。");      }      public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {          System.out.println("doFilter 。。。");          chain.doFilter(request, response);      }      public void destroy() {          System.out.println("Filter 销毁。。。");      } }

Listener 初始化

import javax.servlet.ServletContextEvent;import javax.servlet.ServletContextListener;public class TestListener implements ServletContextListener{  public void contextInitialized(ServletContextEvent arg0) {          System.out.println("Listener 初始化。。。");      }      public void contextDestroyed(ServletContextEvent arg0) {          System.out.println("Listener 销毁。。。");      } }

web.xml

<servlet>         <servlet-name>s</servlet-name>         <servlet-class>com.zm.test.TestServlet</servlet-class>     </servlet>     <servlet-mapping>         <servlet-name>s</servlet-name>         <url-pattern>/login</url-pattern>     </servlet-mapping>     <filter>         <filter-name>f</filter-name>         <filter-class>com.zm.test.TestFilter</filter-class>     </filter>     <filter-mapping>         <filter-name>f</filter-name>         <url-pattern>/*</url-pattern>     </filter-mapping>     <listener>         <listener-class>com.zm.test.TestListener</listener-class>     </listener>

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