Servlet生命周期方法，request.getRequestDispatcher
1,request.getRequestDispatcher 方法全称javax.servlet.ServletRequest.getRequestDispatcher(String)
2，在web.xml中配置url-mapping的时候，需要以/开头，否则tomcat启动过程报错；
3，servlet先调用构造函数，再调用init方法；
不进行http请求tomcat不会初始化servlet，关闭tomcat的时候会调用destroy()方法；
package com.stono.servlet; import java.io.IOException; import javax.servlet.RequestDispatcher; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; public class TestServlet extends HttpServlet { private static final long serialVersionUID = 1L; public TestServlet() { System.out.println("com.stono.servlet.TestServlet constructor called"); } @Override public void init() throws ServletException { System.out.println("com.stono.servlet.TestServlet.init() called"); } @Override public void destroy() { System.out.println("com.stono.servlet.TestServlet.destroy() called"); } @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { RequestDispatcher dispatcher = req.getRequestDispatcher("test2.do"); dispatcher.forward(req, resp); } @Override protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { } }
2015-9-22 8:57:40 org.apache.catalina.core.AprLifecycleListener init 信息: Loaded APR based Apache Tomcat Native library 1.1.24 using APR version 1.4.6. 2015-9-22 8:57:40 org.apache.catalina.core.AprLifecycleListener init 信息: APR capabilities: IPv6 [true], sendfile [true], accept filters [false], random [true]. 2015-9-22 8:57:40 org.apache.catalina.core.AprLifecycleListener initializeSSL 信息: OpenSSL successfully initialized (OpenSSL 1.0.1c 10 May 2012) 2015-9-22 8:57:40 org.apache.coyote.AbstractProtocol init 信息: Initializing ProtocolHandler ["http-apr-8080"] 2015-9-22 8:57:40 org.apache.coyote.AbstractProtocol init 信息: Initializing ProtocolHandler ["ajp-apr-8009"] 2015-9-22 8:57:40 org.apache.catalina.startup.Catalina load 信息: Initialization processed in 851 ms 2015-9-22 8:57:40 org.apache.catalina.core.StandardService startInternal 信息: Starting service Catalina 2015-9-22 8:57:40 org.apache.catalina.core.StandardEngine startInternal 信息: Starting Servlet Engine: Apache Tomcat/7.0.35 2015-9-22 8:57:40 org.apache.catalina.startup.HostConfig deployDirectory 信息: Deploying web application directory D:\Java\apache-tomcat-7.0.35\webapps\TestBootWeb 2015-9-22 8:57:41 org.apache.coyote.AbstractProtocol start 信息: Starting ProtocolHandler ["http-apr-8080"] 2015-9-22 8:57:41 org.apache.coyote.AbstractProtocol start 信息: Starting ProtocolHandler ["ajp-apr-8009"] 2015-9-22 8:57:41 org.apache.catalina.startup.Catalina start 信息: Server startup in 322 ms com.stono.servlet.TestServlet constructor called com.stono.servlet.TestServlet.init() called do get method called! 2015-9-22 8:57:47 org.apache.catalina.core.StandardServer await 信息: A valid shutdown command was received via the shutdown port. Stopping the Server instance. 2015-9-22 8:57:47 org.apache.coyote.AbstractProtocol pause 信息: Pausing ProtocolHandler ["http-apr-8080"] 2015-9-22 8:57:47 org.apache.coyote.AbstractProtocol pause 信息: Pausing ProtocolHandler ["ajp-apr-8009"] 2015-9-22 8:57:47 org.apache.catalina.core.StandardService stopInternal 信息: Stopping service Catalina com.stono.servlet.TestServlet.destroy() called 2015-9-22 8:57:47 org.apache.coyote.AbstractProtocol stop 信息: Stopping ProtocolHandler ["http-apr-8080"] 2015-9-22 8:57:47 org.apache.coyote.AbstractProtocol stop 信息: Stopping ProtocolHandler ["ajp-apr-8009"] 2015-9-22 8:57:47 org.apache.coyote.AbstractProtocol destroy 信息: Destroying ProtocolHandler ["http-apr-8080"] 2015-9-22 8:57:47 org.apache.coyote.AbstractProtocol destroy 信息: Destroying ProtocolHandler ["ajp-apr-8009"]
