import javax.servlet.*;

import javax.servlet.http.*;

servlet的配置

　　1、导入包：jsp-api.jar，servlet-api.jar

　　2、把servlet源文件SimpleServlet.java放在WEB-INF\classes路径下

　　3、修改web.xml配置文件如下

　　<servlet>

                <servlet-name>SimpleServlet</servlet-name>

                <servlet-class>com.bn.SimpleServlet</servlet-class>

　　　　　　</servlet>

　　　　<servlet-mapping>

  　　　　<servlet-name>SimpleServlet</servlet-name>

  　　　　<url-pattern>/tttt</url-pattern>

　　　　</servlet-mapping>

　　4、可在浏览器中输入访问SimpleServlet.java

　　5、最好把tttt改写成有意义的名字如SimpleServlet.java

　　如把配置文件改成如下则可以 添加带初始化值：

<servlet>

                <servlet-name>SimpleServlet</servlet-name>

                <servlet-class>com.bn.SimpleServlet</servlet-class>

　　　　<init-param>

           <param-name>count</param-name>

           <param-value>128</param-value>

        </init-param>   

</servlet>

　　　　<servlet-mapping>

  　　　　<servlet-name>SimpleServlet</servlet-name>

  　　　　<url-pattern>/tttt</url-pattern>

　　　　</servlet-mapping>

    例：

　　1、ParamServlet.java//有参数的

package com.bn;

import javax.servlet.*;

import javax.servlet.http.*;

import java.io.*;

public class ParamServlet extends HttpServlet

{

 @Override

 public  void doGet(HttpServletRequest request,

                     HttpServletResponse response)

              throws ServletException,

                     IOException

    {

     doPost(request,response);

    }

   

    @Override

    public  void doPost(HttpServletRequest request,

                     HttpServletResponse response)

              throws ServletException,

                     IOException

    {

     String uname=request.getParameter("uname");

     

     PrintWriter out=response.getWriter();

     response.setContentType("text/html");

     out.print("Hello,"+uname+", this is the message from servlet");

    }

}

2、ToJspServlet.java//跳转到jsp页面

package com.bn;

import javax.servlet.*;

import javax.servlet.http.*;

import java.io.*;

public class ToJspServlet extends HttpServlet

{

 @Override

 public  void doGet(HttpServletRequest request,

                     HttpServletResponse response)

              throws ServletException,

                     IOException

    {

     doPost(request,response);

    }

   

    @Override

    public  void doPost(HttpServletRequest request,

                     HttpServletResponse response)

              throws ServletException,

                     IOException

    {

     request.getRequestDispatcher("toServlet.jsp").forward(request,response);//页面跳转

    }

}

3、 InitServlet.java//配置文件中有默认初始化值时

package com.bn;

import javax.servlet.*;

import javax.servlet.http.*;

import java.io.*;

public class InitServlet extends HttpServlet

{

    public void doGet (HttpServletRequest request,HttpServletResponse response) throws IOException

    {

       String count=this.getInitParameter("count");  //获得默认值

       response.getWriter().println("<font size=6 color=red>count: "+count+"</font>");

    }

}