Accessing Databases with JDBC - Java: How to Program Early Objects - page 1068

ResultSetTableModel Class
Class ResultSetTableModel (Fig. 24.25) extends class AbstractTableModel (package
javax.swing.table ), which implements interface TableModel . ResultSetTableModel
overrides TableModel methods getColumnClass , getColumnCount , getColumnName , get-
RowCount and getValueAt . The default implementations of TableModel methods is-
CellEditable and setValueAt (provided by AbstractTableModel ) are not overridden,
because this example does not support editing the JTable cells. The default implementa-
tions of TableModel methods addTableModelListener and removeTableModelListener
(provided by AbstractTableModel ) are not overridden, because the implementations of
these methods in AbstractTableModel properly add and remove event listeners.

1 // Fig. 24.25: ResultSetTableModel.java

2 // A TableModel that supplies ResultSet data to a JTable.

3 import java.sql.Connection;

4 import java.sql.Statement;

5 import java.sql.DriverManager;

6 import java.sql.ResultSet;

7 import java.sql.ResultSetMetaData;

8 import java.sql.SQLException;

9 import javax.swing.table.AbstractTableModel;

10
11 // ResultSet rows and columns are counted from 1 and JTable

12

// rows and columns are counted from 0. When processing

13

// ResultSet rows or columns for use in a JTable, it is

14

// necessary to add 1 to the row or column number to manipulate

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// the appropriate ResultSet column (i.e., JTable column 0 is

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// ResultSet column 1 and JTable row 0 is ResultSet row 1).

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public class ResultSetTableModel extends AbstractTableModel

18

{

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private final Connection connection;

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private final Statement statement;

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private ResultSet resultSet;

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private ResultSetMetaData metaData;

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private int numberOfRows;

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25

// keep track of database connection status
private boolean connectedToDatabase = false ;

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// constructor initializes resultSet and obtains its metadata object;

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// determines number of rows

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public ResultSetTableModel(String url, String username,

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String password, String query) throws SQLException

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{

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// connect to database

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connection = DriverManager.getConnection(url, username, password);

35
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// create Statement to query database
statement = connection.createStatement(
ResultSet.TYPE_SCROLL_INSENSITIVE ,
ResultSet.CONCUR_READ_ONLY );

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Fig. 24.25 | A TableModel that supplies ResultSet data to a JTable . (Part 1 of 4.)