Servlet相关配置

配置方式

webXML

定义标签

<url-pattern>

Servlet访问路径

<!--配置Servlet-->
<servlet>
    <!--起个短名-->
    <servlet-name>demo1</servlet-name>
    <!--全类名-->
    <servlet-class>cn.itcast.web.servlet.ServletDemo1</servlet-class>
</servlet>
<!--映射-->
<servlet-mapping>
    <!--映射名称对应类短名-->
    <servlet-name>demo1</servlet-name>
    <!--资源路径-->
    <url-pattern>/demo1</url-pattern>
</servlet-mapping>

注解

定义的<urlpartten>数组：可以为一个servlet定义多个访问路径。

 package cn.itcast.web.servlet;

 import javax.servlet.ServletException;
 import javax.servlet.annotation.WebServlet;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import java.io.IOException;

 /**
  * @author 旗木五五开
  * @create 2020-02-19 0:08
  */
 @WebServlet({"/d4","/dd4","/ddd4"})
 //{}多个，数组用大括号
 public class ServletDemo4 extends HttpServlet {
     @Override
     protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
         System.out.println("doGet");
     }
 }

路径定义规则

1. /xxx
2. /xxx/xxx：多层路径。目录结构
3. /*.do

多层路径。目录结构

 package cn.itcast.web.servlet;

 import javax.servlet.ServletException;
 import javax.servlet.annotation.WebServlet;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import java.io.IOException;

 /**
  * @author 旗木五五开
  * @create 2020-02-19 0:08
  */
 @WebServlet("/user/demo4")
 public class ServletDemo4 extends HttpServlet {
     @Override
     protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
         System.out.println("doGet");
     }
 }

*代表任意，想写啥就写啥，写啥都能访问到。直接写/*。后面写什么都能访问到

优先级最低，别的都访问不到，才访问

 package cn.itcast.web.servlet;

 import javax.servlet.ServletException;
 import javax.servlet.annotation.WebServlet;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import java.io.IOException;

 /**
  * @author 旗木五五开
  * @create 2020-02-19 0:08
  */
 @WebServlet("/user/*")
 public class ServletDemo4 extends HttpServlet {
     @Override
     protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
         System.out.println("doGet");
     }
 }

*.do：*所有，do后缀名。注意不要写错，*.啥都行

注意*前不要加/

加了就——报错

 package cn.itcast.web.servlet;

 import javax.servlet.ServletException;
 import javax.servlet.annotation.WebServlet;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import java.io.IOException;

 /**
  * @author 旗木五五开
  * @create 2020-02-19 0:08
  */
 @WebServlet("*.do")
 public class ServletDemo4 extends HttpServlet {
     @Override
     protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
         System.out.println("doGet");
     }
 }