guestdatabean.java

这是java的一本书上的源代码

// Fig. 25.21: GuestDataBean.java
// Class GuestDataBean makes a database connection and supports 
// inserting and retrieving data from the database.
package com.deitel.jhtp5.jsp.beans;

// Java core packages
import java.io.*;
import java.sql.*;
import java.util.*;

public class GuestDataBean {
   private Connection connection;
   private Statement statement;
   
   // construct TitlesBean object 
   public GuestDataBean() throws Exception
   {
         System.setProperty( "db2j.system.home", "C:/Cloudscape_5.0" );

         // load the Cloudscape driver
         Class.forName("com.ibm.db2j.jdbc.DB2jDriver");

         // connect to the database
         connection = DriverManager.getConnection(
            "jdbc:db2j:guestbook" );

         statement = connection.createStatement();
   }

   // return an ArrayList of GuestBeans
   public List getGuestList() throws SQLException
   {
      List guestList = new ArrayList();

      // obtain list of titles
      ResultSet results = statement.executeQuery( 
         "SELECT firstName, lastName, email FROM guests" );

      // get row data
      while ( results.next() ) {
         GuestBean guest = new GuestBean();

         guest.setFirstName( results.getString( 1 ) );
         guest.setLastName( results.getString( 2 ) );
         guest.setEmail( results.getString( 3 ) );

         guestList.add( guest ); 
      }         

      return guestList; 
   }
   
   // insert a guest in guestbook database
   public void addGuest( GuestBean guest ) throws SQLException
   {
      statement.executeUpdate( "INSERT INTO guests ( firstName, " + 
         "lastName, email ) VALUES ( '" + guest.getFirstName() + "', '" + 
         guest.getLastName() + "', '" + guest.getEmail() + "' )" );
   }

   // close statements and terminate database connection
   protected void finalize()
   {
      // attempt to close database connection
      try {
         statement.close();
         connection.close();
      }

      // process SQLException on close operation
      catch ( SQLException sqlException ) {
         sqlException.printStackTrace();
      }
   }
}


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