seatinfo.java~9~

航班查询与订票系统 用Java与sqlserver2000来编写一个航班查询与订票系统

package flight.assist;

import flight.assist.*;

import javax.swing.*;
import java.io.*;
import java.sql.*;

public class SeatInfo {
  DataBaseManager dbManager = DataBaseManager.getInstance();
  private SqlBean sqlBean = new SqlBean();
  private RandomAccessFile raf;
  private final int FLIGHT_PER_DAY = 10;

  public SeatInfo() {
    File file = new File(".", "data");
    file.mkdir();
    File f = new File(file, "SeatInfo.txt");

    try {
      raf = new RandomAccessFile(f, "rw");

      if (raf.length() == 0) {
        raf.setLength(31 * 4 * FLIGHT_PER_DAY);
        for (int i = 0; i < 31 * FLIGHT_PER_DAY; i++)
          raf.writeInt(0);
      }
    }
    catch (Exception e) {
      e.printStackTrace();
    }

  }
  //判断航班是否已满
  public boolean isFull(String flightNum, String day) {
    String sqlString = "select orderedSeats from orderedSeats where flight='" + flightNum +
          "' and flightdate='"+day+"'";
    ResultSet rs =dbManager.getResult(sqlString);
    try{
      if (!rs.next()) {
        sqlString = "insert into orderedSeats values('flightNum','day',0)";
        dbManager.updateSql(sqlString);
        return false;
      }
      else {
        int orderSeats = rs.getInt(1);
        sqlString = "select seat from flight where flight='" + flightNum + "'";
        rs = dbManager.getResult(sqlString);
        int totalSeats = 0;
        if (rs.next())
          totalSeats = rs.getInt(1);
        if (totalSeats == orderSeats)
          return true;
        else
          return false;
      }
    }catch(Exception e){
      e.printStackTrace();
      return false;
    }
    /*
    try {
      long index = cacuIndex(day);
      long address = cacuAddr(flightNum);
      long absoluteAddress = index + address;

      raf.seek(absoluteAddress);
      int bookedSeats = raf.readInt();
      String sqlString = "select seat from flight where flight='" + flightNum +
          "'";
      ResultSet rs = sqlBean.executeQuery(sqlString);

      int totalSeats = 0;

      while (rs.next())
        totalSeats = rs.getInt(1);
      if (totalSeats == bookedSeats)
        return true;
      else
        return false;

    }
    catch (Exception e) {
      return false;
    }*/
  }

  public int dingPiao(String flightNum, String day, int seats) {
    int leftSeats = 0;
    try {
      long index = cacuIndex(day);
      long address = cacuAddr(flightNum);
      long absoluteAddress = index + address;

      raf.seek(absoluteAddress);
      int bookedSeats = raf.readInt();

      String sqlString = "select seat,week from flight where flight='" +
          flightNum + "' ";
      ResultSet rs = sqlBean.executeQuery(sqlString);

      int totalSeats = 0;
      String week = "";
      while (rs.next()) {
        totalSeats = rs.getInt(1);
        week = rs.getString(2);
      }

      String c = isAbsence(day);
      int flag = 0;
      for (int i = 0; i < week.length(); i++) {
        String w = week.substring(i, i + 1);
        if (c.equals(w)) {
          flag = 1;
          break;
        }
      }

      if (flag == 1) {
        leftSeats = totalSeats - bookedSeats;

        if (leftSeats >= seats) {
          raf.seek(absoluteAddress);
          raf.writeInt(bookedSeats + seats);
          return -1;
        }
        else
          return leftSeats;
      }
      else
        return -2;

    }
    catch (Exception e) {
      e.printStackTrace();
    }

    return leftSeats;
  }

  public void tuiPiao(String flightNum, String day, int seats) {
    try {
      long index = cacuIndex(day);
      long address = cacuAddr(flightNum);
      long absoluteAddress = index + address;

      raf.seek(absoluteAddress);
      int bookedSeats = raf.readInt();

      if (bookedSeats < seats)
        JOptionPane.showMessageDialog(null, "退票数大于已定票数!",
                                      "错误信息", JOptionPane.ERROR_MESSAGE);
      else {
        raf.seek(absoluteAddress);
        raf.writeInt(bookedSeats - seats);
      }
    }
    catch (Exception e) {
    }
  }

  public long cacuIndex(String day) {
    String d = day.substring(6, 8);
    long index = Long.parseLong(d);

    return (index - 1) * 4 * FLIGHT_PER_DAY;
  }

  public long cacuAddr(String flightNum) {
    long remark = 0;
    try {
      String sqlString = "select remark from flight where flight='" + flightNum +
          "'";
      ResultSet rs = sqlBean.executeQuery(sqlString);

      while (rs.next())
        remark = rs.getInt(1);
    }
    catch (Exception e) {
      e.printStackTrace();
    }

    return (remark - 1) * 4;
  }

  private String timeToWeek(String year, String month, String day) {
    int sum = 0;
    int y = Integer.parseInt(year);
    int m = Integer.parseInt(month);
    int d = Integer.parseInt(day);

    int[] dayOfMonth = {
        0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

    //Caculate the first the day of the designate year is "Xing Qi Ji"
    int firstDayOfYear = firstDay(y);

    for (int i = 1; i < m; i++) {
      sum = sum + dayOfMonth[i];
    }

    sum = sum + (d - 1) + firstDayOfYear;

    //If month is over February and the designate year is leap year,
    //the total days should be add one
    if ( (m >= 2) && ( (y % 4 == 0 && y % 100 != 0) || (y % 400 == 0)))
      sum++;

    int week = 0;
    //The weekday for the designate day is:
    int x = sum % 7;
    switch (x) {
      case 1:
        week = 1;
        break;
      case 2:
        week = 2;
        break;
      case 3:
        week = 3;
        break;
      case 4:
        week = 4;
        break;
      case 5:
        week = 5;
        break;
      case 6:
        week = 6;
        break;
      case 0:
        week = 7;
        break;
    }

    return String.valueOf(week);
  }

  //The method used to caculate the first the day of the designate year is "Xing Qi Ji"
  private int firstDay(int year) {
    int a, b;

    if (year <= 2000) {
      a = 2000 - year;
      b = 6 - (a + a / 4 - a / 100 + a / 400) % 7;
      return b;
    }
    else {
      a = year - 2000;
      b = (a + 1 + (a - 1) / 4 - (a - 1) / 100 + (a - 1) / 400) % 7 + 6;
      return b % 7;
    }
  }

  private String isAbsence(String date) {
    String year = date.substring(0, 4);
    String month = date.substring(4, 6);
    String day = date.substring(6, 8);

    String week = timeToWeek(year, month, day);

    return week;

  }
}