cityweatherreportserver.java

java EJB 编程源代码。

import java.rmi.*;
import java.rmi.server.*;
import java.sql.*;

public class cityWeatherReportServer extends UnicastRemoteObject implements cityWeatherReportInterface
  {
   /* 这是“城市天气预报”的服务器程序，用于响应客户端的请求 */

   Connection con1 = null;    //定义数据库连接对象
   Connection con2 = null;   
   Statement stmt1 = null;    //定义数据库声明对象
   Statement stmt2 = null;   
   ResultSet rset1 = null;    //定义记录结果集对象
   ResultSet rset2 = null;   
   private String cityName = null;

   private cityWeatherReportServer() throws RemoteException
     {
      super();
     }

   public cityWeatherReportServer(String cityName) throws RemoteException
     {
      super();
      this.cityName = cityName;
     }

   public String getCityTemperature() throws RemoteException
     {
      /* 处理城市天气温度的查询请求 */

      String ResponseStr = null;
      String sSQLCmd = null;
      int Recordset1 = 0;
      int Recordset2 = 0;
      String HighTemperature = null;
      String LowTemperature = null;

      if(cityName.equals("") || cityName == null || cityName.length() < 1)
        {
         ResponseStr = "error";
        }
      else
        {
         sSQLCmd = "SELECT HighTemperature, LowTemperature FROM CityWeather WHERE CityName = '"+ cityName +"'";
         
         try
           {
            /* 建立与后台数据库服务器的连接 */ 
            DriverManager.registerDriver(new sun.jdbc.odbc.JdbcOdbcDriver());
            con1 = DriverManager.getConnection("jdbc:odbc:DemoDB","demo","demo");
            stmt1 = con1.createStatement ();
            rset1 = stmt1.executeQuery (sSQLCmd);

            while(rset1.next())
              {
               Recordset1 = rset1.getInt(1); 
               Recordset2 = rset1.getInt(2);
               HighTemperature = Integer.toString(Recordset1);
               LowTemperature = Integer.toString(Recordset2);
               ResponseStr = "（最高气温）" + HighTemperature + "℃" + "  （最低气温）" + LowTemperature + "℃";
              }
            rset1.close();
            con1.close();
           }

         catch(SQLException e)
           {
            ResponseStr = "error";
            System.out.println("!服务器端数据库连接出错：" + e.toString());
           }
        }

      return ResponseStr;
     }

   public String getWeatherForecast() throws RemoteException
     {
      /* 处理城市天气情况的查询请求 */

      String ResponseStr = null;
      String sSQLCmd = null;
      String Recordset1 = null;
      String WeatherInfo = null;

      if(cityName.equals("") || cityName == null || cityName.length() < 1)
        {
         ResponseStr = "error";
        }
      else
        {
         sSQLCmd = "SELECT WeatherInfo FROM CityWeather WHERE CityName = '"+ cityName +"'";
         
         try
           {
            /* 建立与后台数据库服务器的连接 */ 
            DriverManager.registerDriver(new sun.jdbc.odbc.JdbcOdbcDriver());
            con2 = DriverManager.getConnection("jdbc:odbc:DemoDB","demo","demo");
            stmt2 = con2.createStatement ();
            rset2 = stmt2.executeQuery (sSQLCmd);

            while(rset2.next())
              {
               Recordset1 = rset2.getString(1); 
               WeatherInfo = (Recordset1 == null) ? "不详" : Recordset1;
               ResponseStr = WeatherInfo;
              }
            rset2.close();
            con2.close();
           }

         catch(SQLException e)
           {
            ResponseStr = "error";
            System.out.println("!服务器端数据库连接出错：" + e.toString());
           }
        }

      return ResponseStr;

     }
  }