login.java~1~

一个使用java 写的进销存代码 使用了ejb 等技术 是学习j2ee的好

package servlet;

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
import data.*;

public class Login extends HttpServlet {
  private static final String CONTENT_TYPE = "text/html; charset=GBK";
  public void init() throws ServletException {
  }

  public void doPost(HttpServletRequest request, HttpServletResponse response) throws
      ServletException, IOException {
    //设置取得字符串的编码机制
    request.setCharacterEncoding("GBK");
    //设置字符输出的编码机制
    response.setContentType(CONTENT_TYPE);
    //取得html代码输出类
    PrintWriter out = response.getWriter();
    //通过HttpServlet类的getServletContext方法取得application的对象
    ServletContext application = getServletContext();
    //创建session对象
    HttpSession session = request.getSession();
    //声明页面转向类
    RequestDispatcher requestDispatcher = null;
    //取得按钮的字符
    String action = request.getParameter("action");
    //创建钱包数据类
    StockManagementData stockManagementData = new StockManagementData();
    if(action.equals("登陆")){
      //取得用户名字和密码
      String userName = request.getParameter("userName");
      String userPassword = request.getParameter("userPassword");
      int[] result = stockManagementData.checkUser(userName, userPassword);
      if( result[0] == -1){
        //创建页面转向类
        requestDispatcher = application.getRequestDispatcher("/error.jsp");
        request.setAttribute("infor", "用户的名字和密码不正确,请<a href=\"login.jsp\">重新"
                             +"输入</a>.");
        requestDispatcher.forward(request, response);
      }else{
        //创建用户类
        User user = new User(String.valueOf(userId), userName, userPassword);
        //将用户放入session对象
        session.setAttribute("user", user);
        //取得用户的钱包记录数组
        String[][] detail = stockManagementData.getWallet(user.getUserId());
        //取得钱包的余额
        double balance = stockManagementData.getBalance(user.getUserId());
        request.setAttribute("balance", new Double(balance));
        request.setAttribute("detail", detail);
        //创建页面转向类
        requestDispatcher = application.getRequestDispatcher("/walletview.jsp");
        requestDispatcher.forward(request, response);
      }
      return;
    }
  }
  public void destroy() {
  }
}