getstocksinfo.java

传智播客ajax课堂源码

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.ServletException;
import javax.servlet.ServletConfig;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.HashMap;

/**
 * Created by IntelliJ IDEA.
 * User: ming
 * Date: 2008-6-14
 * Time: 9:35:50
 * To change this template use File | Settings | File Templates.
 * 返回股票当前信息的servlet
 */
public class GetStocksInfo extends HttpServlet {
    //保存股票对象的map
    private HashMap<String,Stock> stocks;
    protected void doGet(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws ServletException, IOException {
        //返回两只股票的价格信息

        //1。计算随机数
        double sz = Math.random() * 20;
        double pf = Math.random() * 0.5;

        //通过随机数是奇数还是偶数来判断股票上涨还是下跌
        boolean flagsz = ((int)(Math.random() * 10)) % 2 == 0;
        boolean flagpf = ((int)(Math.random() * 10)) % 2 == 0;

        //2。将随机数和股票的当前价格进行加或减的操作，得到新的当前价格
        Stock szzs = stocks.get("300001");
        Stock pfyh = stocks.get("000001");
        double temp;
        if (flagsz) {
            temp = szzs.getNow() + sz;
        } else {
            temp = szzs.getNow() - sz;
        }
        //需要对新的当前价格进行截取，只保留小数点后两位
        temp = (int)(temp * 100) / 100.0;
        szzs.setNow(temp);
        if (flagpf) {
            temp = pfyh.getNow() + pf;
        } else {
            temp = pfyh.getNow() - pf;
        }
        temp = (int)(temp * 100) / 100.0;
        pfyh.setNow(temp);


        httpServletResponse.setContentType("text/html;charset=gb2312");
        PrintWriter out = httpServletResponse.getWriter();
        //out.println(szzs + "<br />" + pfyh);
        //3。返回两只股票的昨天收盘，今天开盘和当前价格
        //采用json的数据格式返回股票的信息
        StringBuilder builder = new StringBuilder();
        //采用数组的方式回传两个股票对象
        /*
        builder.append("[{name:\"").append(szzs.getName()).append("\",id:\"").append(szzs.getId())
                .append("\",yes:").append(szzs.getYesterday()).append(",tod:").append(szzs.getToday())
                .append(",now:").append(szzs.getNow())
                .append("},")
                .append("{name:\"").append(pfyh.getName()).append("\",id:\"").append(pfyh.getId())
                .append("\",yes:").append(pfyh.getYesterday()).append(",tod:").append(pfyh.getToday())
                .append(",now:").append(pfyh.getNow())
                .append("}]");
        */
        //采用对象的方式回传两个股票对象
        builder.append("{")
                .append("\"").append(szzs.getId()).append("\":{name:\"").append(szzs.getName())
                .append("\",yes:").append(szzs.getYesterday()).append(",tod:").append(szzs.getToday())
                .append(",now:").append(szzs.getNow())
                .append("},")
                .append("\"").append(pfyh.getId()).append("\":{name:\"").append(pfyh.getName())
                .append("\",yes:").append(pfyh.getYesterday()).append(",tod:").append(pfyh.getToday())
                .append(",now:").append(pfyh.getNow())
                .append("}}");
        out.println(builder);

    }

    protected void doPost(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws ServletException, IOException {
        doGet(httpServletRequest, httpServletResponse);
    }

    public void init(ServletConfig servletConfig) throws ServletException {
        stocks = new HashMap<String,Stock>();
        //创建股票
        Stock szzs = new Stock(3000.0,2990.1,"上证指数","300001");
        Stock pfyh = new Stock(23.22, 23.50,"浦发银行","000001");

        //将两只股票保存在stocks的map中
        stocks.put(szzs.getId(),szzs);
        stocks.put(pfyh.getId(),pfyh);

        System.out.println(stocks);
    }
}