package com.ccc.pro;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class ServletProj extends HttpServlet{

	@Override
	protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		String category=request.getParameter("category");
		String html="<h2 style='color:blue'>"+category+"</h2>";
		PrintWriter out=response.getWriter();
		out.println(html);
	}

}

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
  <display-name>ServletProj</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
  <servlet>
    <servlet-name>pro</servlet-name>
    <servlet-class>com.ccc.pro.ServletProj</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>pro</servlet-name>
    <url-pattern>/ShopServlet</url-pattern>
  </servlet-mapping>
</web-app>