Re: [java-list] JAVA E ACCESS

Cesar Hunning Fri, 04 Jul 2003 10:38:20 -0700

Iva !!

A classe abaixo implementa uma janela com 2 frames.

- uma para digitar um comando sql simples (select)

- outra que mostrará o resultado do select.

OBS: Esta classe acessa o Postgre. Nao tenho disponível no momento a string de conexao ao Access.

T+,

import java.sql.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;

public class Display extends JFrame {
   // java.sql types needed for database processing
   private Connection connection;
   private Statement statement;
   private ResultSet resultSet;
   private ResultSetMetaData rsMetaData;

   // javax.swing types needed for GUI
   private JTable table;
   private JTextArea inputQuery;
   private JButton submitQuery;

   public Display()
   {
      super( "Enter Query. Click Submit to See Results." );

      // The URL specifying the Books database to which
      // this program connects using JDBC to connect to a
      // Microsoft ODBC database.
      String url = "";
      String username = "postgres";
      String password = "";

      // Load the driver to allow connection to the database
      try {
         Class.forName( "org.postgresql.Driver" );

         connection = DriverManager.getConnection(
            url, username, password );
      }
      catch ( ClassNotFoundException cnfex ) {
         System.err.println(
            "Failed to load driver." );
         cnfex.printStackTrace();
         System.exit( 1 ); // terminate program
      }
      catch ( SQLException sqlex ) {
         System.err.println( "Unable to connect" );
         sqlex.printStackTrace();
         System.exit( 1 ); // terminate program
      }

      // If connected to database, set up GUI
      inputQuery =
         new JTextArea( "SELECT * FROM clientes", 4, 30 );
      submitQuery = new JButton( "Submit query" );
      submitQuery.addActionListener(
         new ActionListener() {
            public void actionPerformed( ActionEvent e )
            {
               getTable();
            }
         }
      );

      JPanel topPanel = new JPanel();
      topPanel.setLayout( new BorderLayout() );
      topPanel.add( new JScrollPane( inputQuery),
                    BorderLayout.CENTER );
      topPanel.add( submitQuery, BorderLayout.SOUTH );

      table = new JTable( 4, 4 );

      Container c = getContentPane();
      c.setLayout( new BorderLayout() );
      c.add( topPanel, BorderLayout.NORTH );
      c.add( table, BorderLayout.CENTER );

getTable();

      setSize( 500, 500 );
      show();
   }

   private void getTable()
   {
      try {
         String query = inputQuery.getText();

         statement = connection.createStatement();
         resultSet = statement.executeQuery( query );
         displayResultSet( resultSet );
      }
      catch ( SQLException sqlex ) {
         sqlex.printStackTrace();
      }
   }

   private void displayResultSet( ResultSet rs )
      throws SQLException
   {
      // position to first record
      boolean moreRecords = rs.next();

      // If there are no records, display a message
      if ( ! moreRecords ) {
         JOptionPane.showMessageDialog( this,
            "ResultSet contained no records" );
         setTitle( "No records to display" );
         return;
      }

Vector columnHeads = new Vector();
Vector rows = new Vector();

      try {
         // get column heads
         ResultSetMetaData rsmd = rs.getMetaData();

         for ( int i = 1; i <= rsmd.getColumnCount(); ++i )
            columnHeads.addElement( rsmd.getColumnName( i ) );

         // get row data
         do {
            rows.addElement( getNextRow( rs, rsmd ) );
         } while ( rs.next() );

         // display table with ResultSet contents
         table = new JTable( rows, columnHeads );
         JScrollPane scroller = new JScrollPane( table );
         Container c = getContentPane();
         c.remove( 1 );
         c.add( scroller, BorderLayout.CENTER );
         c.validate();
      }
      catch ( SQLException sqlex ) {
         sqlex.printStackTrace();
      }
   }

   private Vector getNextRow( ResultSet rs,
                              ResultSetMetaData rsmd )
       throws SQLException
   {
      Vector currentRow = new Vector();

      for ( int i = 1; i <= rsmd.getColumnCount(); ++i )
         switch( rsmd.getColumnType( i ) ) {
            case Types.VARCHAR:
            case Types.LONGVARCHAR:
                  currentRow.addElement( rs.getString( i ) );
               break;
            case Types.INTEGER:
                  currentRow.addElement(
                     new Long( rs.getLong( i ) ) );
               break;
            default:
               System.out.println( "Type was: " +
                  rsmd.getColumnTypeName( i ) );
         }

      return currentRow;
   }

   public void shutDown()
   {
      try {
         connection.close();
      }
      catch ( SQLException sqlex ) {
         System.err.println( "Unable to disconnect" );
         sqlex.printStackTrace();
      }
   }

   public static void main( String args[] )
   {
      final Display app = new Display();

      app.addWindowListener(
         new WindowAdapter() {
            public void windowClosing( WindowEvent e )
            {
               app.shutDown();
               System.exit( 0 );
            }
         }
      );
   }

}

----- Original Message -----

From: iva conte

To: [EMAIL PROTECTED]

Sent: Tuesday, July 01, 2003 5:11 PM

Subject: [java-list] JAVA E ACCESS

POR FAVOR!

ESTOW TENTANDO APRENDER A FAZER COM Q UM PROJETO JAVA POSSA SE COMUNICAR COM UM BANCO DE DADOS EM ACCESS! MAS NAUM TENHU A MENOR IDEIA D COMO FUNCIONA!

ALGUEM PODERIA ME DAR UMA AJUDA? QUAL O PACOTE Q FAZ ISSO?

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Re: [java-list] JAVA E ACCESS

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