java - tomcat 无法获取 ServletContext.getContextPath()

Question

我正在尝试获取 contextPath 但出现此异常

ServletContextHandler.contextInitialized()HERE MY PRINT
 2011-02-22 02:45:38,614 ERROR main tomcat.localhost./photo.Context - Error listenerStart
 2011-02-22 02:45:38,615 ERROR main tomcat.localhost./photo.Context - Context startup failed due to previous errors

这是我的 ServletContextListener 类

public class ServletContextHandler implements ServletContextListener {
  private final static Logger logger = Logger.getLogger(ServletContextHandler.class);

  public ServletContextHandler(){}

  public void contextInitialized(ServletContextEvent contextEvent){
    try{
    //LOG DEBUG
    logger.debug("Server.init()-> set context path");
    System.out.println("ServletContextHandler.contextInitialized()HERE MY PRINT");
    System.out.println("ServletContextHandler.contextInitialized() " + contextEvent.getServletContext().getContextPath());
    }catch(Exception e){
      e.printStackTrace();
    }
  }

  public void contextDestroyed(ServletContextEvent contextEvent){
  }

}

这是我的 web.xml

<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN" "http://java.sun.com/j2ee/dtds/web-app_2_3.dtd">

<web-app>
     <listener>
        <listener-class>
            utils.ServletContextHandler
        </listener-class>
    </listener>
</web-app>

你能帮帮我吗？

Answer 1

ServletContext.getContextPath() 仅适用于 Servlet 2.5 规范。您的 web.xml 部署描述符使用 2.3 DTD，因此它强制与 Servlet 2.3 兼容。如果您在 Tomcat 6.0.x 或更高版本上运行，请将 web.xml 中的 DOCTYPE 与 2.5 架构引用交换:

<web-app xmlns="http://java.sun.com/xml/ns/javaee"
   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
   version="2.5">

如果解决了问题，请告诉我。