guess.java

猜数字游戏

package game;

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
import javax.swing.JOptionPane;

public class guess extends HttpServlet {
    private static final String CONTENT_TYPE = "text/html; charset=GBK";

    //Initialize global variables
    public void init() throws ServletException {
    }

    //Process the HTTP Get request
    public void doGet(HttpServletRequest request, HttpServletResponse response) throws
            ServletException, IOException {

        //1.取请求中的参数
        String numStr = request.getParameter("num");
        int num = Integer.parseInt(numStr);

        //2.从session中取随机数
        HttpSession ses = request.getSession();
        Integer randNum = (Integer) ses.getAttribute("rand");

        if (randNum == null) {
            java.util.Random random = new java.util.Random();
            randNum = random.nextInt(100); //产生随机数
            ses.setAttribute("rand", randNum); //把随机数放入session
        }

        //3.取猜过的次数
        Integer guessTimes = (Integer) ses.getAttribute("guessTimes");
        if (guessTimes == null) {
            guessTimes = new Integer(1);
            ses.setAttribute("guessTimes", guessTimes); //把次数放入session
        } else {
            guessTimes++;
            ses.setAttribute("guessTimes", guessTimes);
        }

        //判断已经产生的随机数和用户输入的数是否相等
        if (num == randNum) {
            //跳转到ok.jsp
            request.getRequestDispatcher("/ok.jsp").forward(request,response);
        } else {
            if (num > randNum) {
                //用户猜的数字偏大
                request.setAttribute("result", "偏大");
            } else {
                //用户猜的数字偏小
                request.setAttribute("result", "偏小");
            }
            //继续猜,跳转到index.jsp
            request.getRequestDispatcher("/index.jsp").forward(request,response);
        }
    }

    //Process the HTTP Post request
    public void doPost(HttpServletRequest request,
                       HttpServletResponse response) throws
            ServletException, IOException {
        doGet(request, response);
    }

    //Clean up resources
    public void destroy() {
    }
}