-1
我試圖使用ServletContextListener運行一個servlet，我已經把 「Head-First」編寫的代碼放在了「Kathy sierra」中，但這不起作用，它顯示404錯誤。已將類文件放在目錄C：\ Tomcat 5.5 \ webapps \ Listener_exe \ web-inf \ classes \ com \ example中。 web-inf目錄中的web.xml文件。所以請顯示我的 做錯了。這裏是servlet，java文件和xml文件.`上下文監聽器中的問題
package com.example;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
public class ListenerTester extends HttpServlet
{
public void doGet(HttpServletRequest request,HttpServletResponse response) throws IOException,ServletException
{
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out.println("<html><body>test context attributes set by listener<br>");
Dog dog = (Dog) getServletContext().getAttribute("dog");
out.println("Dog's breed is: "+dog.getBreed()+</body></html>);
}
}
package com.example;
public class Dog
{
private String breed;
public Dog(String breed)
{
this.breed=breed;
}
public String getBreed()
{
return breed;
}
}
package com.example;
import javax.servlet.*;
public class MyServletContextListener implements ServletContextListener
{
public void contextInitialized(ServletContextEvent event)
{
ServletContext sc = event.getServletContext();
String dogBreed = sc.getInitParameter("breed");
Dog d = new Dog(dogBreed);
sc.setAttribute("dog",d);
}
public void contextDestroyed(ServletContextEvent event)
{}
}
<web-app>
<servlet>
<servlet-name>ListenerTester</servlet-name>
<servlet-class>com.example.ListenerTester</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>ListenerTester</servlet-name>
<url-pattern>/ListenerTester</url-pattern>
</servlet-mapping>
<Context-param>
<param-name>breed</param-name>
<param-value>Great Dane</param-value>
</Context-param>
<listener>
<listener-class>
com.example.MyServletContextListener
</listener-class>
</listener>
</web-app>