I'm trying to figure out how to make a table window update once the model has changed using an example from another site. Everything works but I can't figure how to refresh the window once the table model has changed.
EDIT: I used the suggestion from Bell and re-arranged some things so that the constructor calls my getmodel3 method to populate the table. I thought I could use the setmodel method to change the model and update the table but it isn't working as I thought. Here's what I thought would, but doesn't happen:
main method creates a new instance of the table using the model passed from the getmodel3 method.setmodel method to load different data into a new model using the returned model from getmodel4.What actually happens is, a new instance is created and uses the model returned from getmodel3, then the setmodel method runs and updates the model variable from a different set of data, but the table doesn't show the change.
public class myTable extends JFrame
{
public volatile DefaultTableModel model = (DefaultTableModel) myTable.getmodel3();
public void setmodel(DefaultTableModel newModel)
{
this.model = newModel;
}
public myTable()
{
JTable table = new JTable( model );
JScrollPane scrollPane = new JScrollPane( table );
getContentPane().add( scrollPane );
JPanel buttonPanel = new JPanel();
getContentPane().add( buttonPanel, BorderLayout.SOUTH );
}
public static void main(String[] args)
{
myTable frame = new myTable();
frame.setDefaultCloseOperation( EXIT_ON_CLOSE );
frame.pack();
frame.setVisible(true);
frame.setmodel(getmodel4());
}
Here is getmodel3 which is identical to getmodel4 except they point to different database files for different data.
public static DefaultTableModel getmodel3(){
Vector<Object> columnNames = new Vector<Object>();
Vector<Object> data = new Vector<Object>();
try
{
// Connect to an Access Database
String url = "jdbc:sqlite:c:\\sqlite3\\test.db";
Connection conn = DriverManager.getConnection(url);
// Read data from a table
String sql = "Select * from Tasks";
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery( sql );
ResultSetMetaData md = rs.getMetaData();
int columns = md.getColumnCount();
// Get column names
for (int i = 1; i <= columns; i++)
{
columnNames.addElement( md.getColumnName(i) );
}
// Get row data
while (rs.next())
{
Vector<Object> row = new Vector<Object>(columns);
for (int i = 1; i <= columns; i++)
{
row.addElement( rs.getObject(i) );
}
data.addElement( row );
}
rs.close();
stmt.close();
conn.close();
}
catch(Exception e)
{
System.out.println( e );
}
// Create table with database data
DefaultTableModel model = new DefaultTableModel(data, columnNames)
{
@Override
public Class getColumnClass(int column)
{
for (int row = 0; row < getRowCount(); row++)
{
Object o = getValueAt(row, column);
if (o != null)
{
return o.getClass();
}
}
return Object.class;
}
};
System.out.println("got model");
return model;
}
Well, with some of your help I finally figured it out. setModel wasn't working because 1, it wasn't accessible from the scope of the method where I tried to use it, and 2 I tried to make my own setter setmodel but I had no idea what I was doing :).
In the end, I initialized in an easier to reach place so I didn't mess with objects in other methods. Here is the working result that loads a table when main is called and later I can call the update method to reload it. Thanks for the help folks.
public class able extends JFrame
{
//initialize here for easy access. getmodel3() is the model getter method and
//returns the defaultTableModel object
private static able frame = new able();
private static JTable table = new JTable( getmodel3() );
//Start all main stuff here using the previously initialized objects.
public static void main(String[] args)
{
JScrollPane scrollPane = new JScrollPane( table );
frame.getContentPane().add( scrollPane );
JPanel buttonPanel = new JPanel();
frame.getContentPane().add( buttonPanel, BorderLayout.SOUTH );
frame.setDefaultCloseOperation( EXIT_ON_CLOSE );
frame.pack();
frame.setVisible(true);
}
public static void update()
{
table.setModel(getmodel3());
}
//This method makes the table model from sql result set and returns it.
//(found online somewhere thanks to whoever wrote it)
public static DefaultTableModel getmodel3(){
Vector<Object> columnNames = new Vector<Object>();
Vector<Object> data = new Vector<Object>();
try
{
// Connect to an Access Database
String url = "jdbc:sqlite:c:\\sqlite3\\test.db";
Connection conn = DriverManager.getConnection(url);
// Read data from a table
String sql = "Select * from Tasks";
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery( sql );
ResultSetMetaData md = rs.getMetaData();
int columns = md.getColumnCount();
// Get column names
for (int i = 1; i <= columns; i++)
{
columnNames.addElement( md.getColumnName(i) );
}
// Get row data
while (rs.next())
{
Vector<Object> row = new Vector<Object>(columns);
for (int i = 1; i <= columns; i++)
{
row.addElement( rs.getObject(i) );
}
data.addElement( row );
}
rs.close();
stmt.close();
conn.close();
}
catch(Exception e)
{
System.out.println( e );
}
// Create table with database data
DefaultTableModel model3 = new DefaultTableModel(data, columnNames)
{
@Override
public Class getColumnClass(int column)
{
for (int row = 0; row < getRowCount(); row++)
{
Object o = getValueAt(row, column);
if (o != null)
{
return o.getClass();
}
}
return Object.class;
}
};
System.out.println("got model");
return model3;
}
public static DefaultTableModel getmodel4(){
Vector<Object> columnNames = new Vector<Object>();
Vector<Object> data = new Vector<Object>();
try
{
// Connect to an Access Database
String url = "jdbc:sqlite:c:\\sqlite3\\test2.db";
Connection conn = DriverManager.getConnection(url);
// Read data from a table
String sql = "Select * from Tasks";
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery( sql );
ResultSetMetaData md = rs.getMetaData();
int columns = md.getColumnCount();
// Get column names
for (int i = 1; i <= columns; i++)
{
columnNames.addElement( md.getColumnName(i) );
}
// Get row data
while (rs.next())
{
Vector<Object> row = new Vector<Object>(columns);
for (int i = 1; i <= columns; i++)
{
row.addElement( rs.getObject(i) );
}
data.addElement( row );
}
rs.close();
stmt.close();
conn.close();
}
catch(Exception e)
{
System.out.println( e );
}
// Create table with database data
DefaultTableModel model3 = new DefaultTableModel(data, columnNames)
{
@Override
public Class getColumnClass(int column)
{
for (int row = 0; row < getRowCount(); row++)
{
Object o = getValueAt(row, column);
if (o != null)
{
return o.getClass();
}
}
return Object.class;
}
};
System.out.println("got model");
return model3;
}
}