Tomcat default servlet

每个servlet容器都有一个默认的servlet，一般都叫做default

<display-name>servletDefault</display-name>
  <servlet>
      <servlet-name>dummy</servlet-name>
      <servlet-class>liulixin.DummyServlet</servlet-class>
    </servlet>
    <servlet-mapping>
      <servlet-name>dummy</servlet-name>
      <url-pattern>/dummy</url-pattern>
    </servlet-mapping>
    <!-- 这种利用default servlet访问静态资源的方式在tomcat 6.0.30及以后版本中已经被禁用了 -->
     <servlet-mapping>
        <servlet-name>default</servlet-name>
        <url-pattern>/static/index.html</url-pattern>
    </servlet-mapping>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>
</web-app>

package liulixin;

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 DummyServlet extends HttpServlet
{
protected void doGet(HttpServletRequest request,
                     HttpServletResponse response)
    throws ServletException, IOException
{
	System.out.println("it does come here");
	final String resourcePath = request.getPathTranslated();
    final String requestURI = request.getRequestURI();
    System.out.println("resourcePath "+resourcePath);
    System.out.println("URI "+requestURI);
	//RequestDispatcher requestDispatcher=getServletContext().getNamedDispatcher("default6");
	//上面这种写法报NullPointerException
	RequestDispatcher requestDispatcher=getServletContext().getNamedDispatcher("default");
	System.out.println(requestDispatcher==null);
	requestDispatcher.forward(request, response);
}
}

输出：

it does come here
resourcePath null
URI /servletDefault/dummy
false

源代码：http://pan.baidu.com/share/link?shareid=1256152557&uk=3878681452