Populating JTable using JDBC recordset 1

[asiavoices]

Hello all,

I've read about JDBC, JTable and Table models and am still having a bit of difficulty in visualizing how I could populate a JTable using my recordset. The examples I've read uses arrays so any code example you could contribute would be great.

Goal:

1. Query the db and create a recordset.

2. Load the recordset into a JTable.

3. Select the row to display the contents onto another view (ie. form)

4. Ability to EDIT the record and updated on the database.

4. Able to delete the entire row in JTable and db.

Am I correct to assume that I should extend Abstract Table Model and use this as my table model? if so how?

Thank you,

Christopher

 

[johnv20]

Hi asiavoices,
did you ever find a way to do this as I'm currently trying to do the same thing and running into difficulties

 

[AlistairMonkeyFinger]

I might be able to help you out on the first part, that is displaying a ResultSet in a JTable. The way i've done it in the past is to create a class that implements TableModel as Christopher suggested, here is some code from something i have....

public class ResultSetTableModel implements TableModel {
    ResultSet results;             // The ResultSet to interpret
    ResultSetMetaData metadata;    // Additional information about the results
    int numcols, numrows;          // How many rows and columns in the table

    /**
     * This constructor creates a TableModel from a ResultSet.  
     **/
  ResultSetTableModel(ResultSet results) throws SQLException {
	this.results = results;                 // Save the results
	metadata = results.getMetaData();       // Get metadata on them
  metadata.isSearchable()
	numcols = metadata.getColumnCount();    // How many columns?
	results.last();                         // Move to last row
	numrows = results.getRow();             // How many rows?
    }
    
    /** 
     * Call this when done with the table model.  It closes the ResultSet and
     * the Statement object used to create it.
     **/
    public void close() {
	try { results.getStatement().close(); }
	catch(SQLException e) {};
    }

    /** Automatically close when we're garbage collected */
    protected void finalize() { close(); }

    // These two TableModel methods return the size of the table
    public int getColumnCount() { return numcols; }
    public int getRowCount() { return numrows; }

    // This TableModel method returns columns names from the ResultSetMetaData
    public String getColumnName(int column) {
	try {
	    return metadata.getColumnLabel(column+1);
	} catch (SQLException e) { return e.toString(); }
    }

    // This TableModel method specifies the data type for each column.  
    // We could map SQL types to Java types, but for this example, we'll just
    // convert all the returned data to strings.
    public Class getColumnClass(int column) { return String.class; }
    
    /**
     * This is the key method of TableModel: it returns the value at each cell
     * of the table.  We use strings in this case.  If anything goes wrong, we
     * return the exception as a string, so it will be displayed in the table.
     * Note that SQL row and column numbers start at 1, but TableModel column
     * numbers start at 0.
     **/
    public Object getValueAt(int row, int column) {
	try {
	    results.absolute(row+1);                // Go to the specified row
	    Object o = results.getObject(column+1); // Get value of the column
	    if (o == null) return null;       
	    else return o.toString();               // Convert it to a string
	} catch (SQLException e) { return e.toString(); }
    }

    // Our table isn't editable
    public boolean isCellEditable(int row, int column) { return false; } 

    // Since its not editable, we don't need to implement these methods
    public void setValueAt(Object value, int row, int column) {}
    public void addTableModelListener(TableModelListener l) {}
    public void removeTableModelListener(TableModelListener l) {}
}

Then you can create a ResultSetTableModel from a ResultSet and use it in the constructor of your table. If you have anymore questions i'll be happy to try and answer them. Alistair