/**

 * Copyright (c) 2014 Oracle and/or its affiliates. All rights reserved.

 *

 * You may not modify, use, reproduce, or distribute this software except in

 * compliance with  the terms of the License at:

 * https://github.com/javaee/tutorial-examples/LICENSE.txt

 */

package javaeetutorial.hello2;

import java.io.IOException;

import java.io.PrintWriter;

import javax.servlet.RequestDispatcher;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

@WebServlet("/greeting")    //以@WebServlet注释开头，注释指定相对于上下文根的URL模式，即在根目录下使用/greeting来访问

  public class GreetingServlet extends HttpServlet {

      @Override

      public void doGet(HttpServletRequest request,    //该servlet重写该doGet方法，实现GET HTTP方法

              HttpServletResponse response)

              throws ServletException, IOException {

         response.setContentType("text/html");    //指定响应页面的类型为html

        response.setBufferSize(8192);    //指定缓冲区大小

         try (PrintWriter out = response.getWriter()) {    //实例化对象out,作为向html页面输出的对象

             //使用println属性，向html页面输出html标签,这里输出的是：             //<html lang=en>

             //    <head>

            //        <title>Servlet Hello</title>

             //    </head>

            out.println("<html lang=\"en\">"

                     + "<head><title>Servlet Hello</title></head>");

             //使用println属性，向html页面输出html标签,这里输出的是：

             //<body  bgcolor=#ffffff>

             //    <img src=resources/images/duke.waving.gif alt=Duke waving his hand>

             //    <form method=get>

             //        <h2>Hello, my name is Duke. What‘s yours?</h2>

             //        <input title=My name is:  type=text name=username size=25/>

             //        <p></p>

             //        <input type=submit value=Submit/>

             //        <input type=reset value=Reset/>

             //    </form>)

             out.println("<body  bgcolor=\"#ffffff\">"

                     + "<img src=\"resources/images/duke.waving.gif\" "

                    + "alt=\"Duke waving his hand\">"

                     + "<form method=\"get\">"

                     + "<h2>Hello, my name is Duke. What‘s yours?</h2>"

                     + "<input title=\"My name is: \" type=\"text\" "

                     + "name=\"username\" size=\"25\"/>"

                    + "<p></p>"

                     + "<input type=\"submit\" value=\"Submit\"/>"

                     + "<input type=\"reset\" value=\"Reset\"/>"

                     + "</form>");

             //使用一个字符串username来获取，第一个input标签内的username的值

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

             if (username != null && username.length() > 0) {

                 RequestDispatcher dispatcher =

                         getServletContext().getRequestDispatcher("/response");

                         //指定要跳转的页面相对于上下文根的URL模式为/response

                 if (dispatcher != null) {

                     //整合request, response然后跳转

                     dispatcher.include(request, response);

                 }

             }

             //使用println属性，向html页面输出html标签,这里输出的是：

             //    </body>

             //</html>

             out.println("</body></html>");

         }

     }

     @Override

    public String getServletInfo() {

         return "The Hello servlet says hello.";

     }

 }

/**

 * Copyright (c) 2014 Oracle and/or its affiliates. All rights reserved.

 *

 * You may not modify, use, reproduce, or distribute this software except in

 * compliance with  the terms of the License at:

 * https://github.com/javaee/tutorial-examples/LICENSE.txt

 */

package javaeetutorial.hello2;

import java.io.IOException;

import java.io.PrintWriter;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

@WebServlet("/response")    //以@WebServlet注释开头，注释指定相对于上下文根的URL模式，

                              //即在根目录下使用/response来访问,这里作为greting页面的响应页面来实现访问

  public class ResponseServlet extends HttpServlet {

      @Override

     public void doGet(HttpServletRequest request,    ////该servlet重写该doGet方法，实现GET HTTP方法

             HttpServletResponse response)

              throws ServletException, IOException {

          try (PrintWriter out = response.getWriter()) {        //实例化对象out,作为向html页面输出的对象

             //接收来自greting页面请求中的input标签中输入的username

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

             if (username != null && username.length() > 0) {

               //使用println属性，向html页面输出html标签,这里输出的是：

                 //<h2>Hello,XXX(前面输入的username的值)!</h2>

                 out.println("<h2>Hello, " + username + "!</h2>");

             }

         }

     }

     @Override

     public String getServletInfo() {

         return "The Response servlet says hello.";

     }

 }