JTable y Eventos

[ferblaca]

Me contesto yo mismo por si a alguien le puede servir de ayuda.
Al crear un JTable pasandole en su constructor los datos, se crea rapidamente una tabla, pero limita mucho las posibilidades a la hora de capturar eventos. Lo mejor para ello, es crear una clase q extienda de AbstractTableModel en la q redefiniremos los metodos tales como "setValueAt" en el cual jugaremos con los datos de la fila seleccionada y con el dato de la columna de esa fila modificada.
Este es un ejemplo de un clase q extiende de la clase AbstractTableModel q una vez construida, solo tendremos q hacer: Jtable tabla = new JTable(new JDBCAdapter()); para construir la tabla.
La clase JDBCAdapter va a la base de datos(SQL Server) a recoger los datos,pero tb se lo podemos pasar construyendo un Object[][], o con 2 vectores (1 con el nombre de columnas y otro con los objetos de cada fila ).

import java.util.Vector;
import java.sql.*;
import javax.swing.table.AbstractTableModel;
import javax.swing.event.TableModelEvent;

public class JDBCAdapter extends AbstractTableModel {
Connection connection;
Statement statement;
ResultSet resultSet;
String[] columnNames = {};
Vector rows = new Vector();
ResultSetMetaData metaData;

public JDBCAdapter(String url, String driverName,
String user, String passwd) {
try {
Class.forName(driverName);
System.out.println("Opening db connection");

connection = DriverManager.getConnection(url, user, passwd);
statement = connection.createStatement();

executeQuery();
}
catch (ClassNotFoundException ex) {
System.err.println("Cannot find the database driver classes.");
System.err.println(ex);
}
catch (SQLException ex) {
System.err.println("Cannot connect to this database.");
System.err.println(ex);
}
}

public void executeQuery(String query) {
if (connection == null || statement == null) {
System.err.println("There is no database to execute the query.");
return;
}
try {
resultSet = statement.executeQuery(query);
metaData = resultSet.getMetaData();

int numberOfColumns = metaData.getColumnCount();
columnNames = new String[numberOfColumns];
// Get the column names and cache them.
// Then we can close the connection.
for(int column = 0; column < numberOfColumns; column++) {
columnNames[column] = metaData.getColumnLabel(column+1);
}

// Get all rows.
rows = new Vector();
while (resultSet.next()) {
Vector newRow = new Vector();
for (int i = 1; i <= getColumnCount(); i++) {
newRow.addElement(resultSet.getObject(i));
}
rows.addElement(newRow);
}
// close(); Need to copy the metaData, bug in jdbc:odbc driver.
fireTableChanged(null); // Tell the listeners a new table has arrived.
}
catch (SQLException ex) {
System.err.println(ex);
}
}

public void close() throws SQLException {
System.out.println("Closing db connection");
resultSet.close();
statement.close();
connection.close();
}

protected void finalize() throws Throwable {
close();
super.finalize();
}

//////////////////////////////////////////////////////////////////////////
//
// Implementation of the TableModel Interface
//
//////////////////////////////////////////////////////////////////////////

// MetaData

public String getColumnName(int column) {
if (columnNames[column] != null) {
return columnNames[column];
} else {
return "";
}
}

public Class getColumnClass(int column) {
int type;
try {
type = metaData.getColumnType(column+1);
}
catch (SQLException e) {
return super.getColumnClass(column);
}

switch(type) {
case Types.CHAR:
case Types.VARCHAR:
case Types.LONGVARCHAR:
return String.class;

case Types.BIT:
return Boolean.class;

case Types.TINYINT:
case Types.SMALLINT:
case Types.INTEGER:
return Integer.class;

case Types.BIGINT:
return Long.class;

case Types.FLOAT:
case Types.DOUBLE:
return Double.class;

case Types.DATE:
return java.sql.Date.class;

default:
return Object.class;
}
}

public boolean isCellEditable(int row, int column) {
try {
return metaData.isWritable(column+1);
}
catch (SQLException e) {
return false;
}
}

public int getColumnCount() {
return columnNames.length;
}

// Data methods

public int getRowCount() {
return rows.size();
}

public Object getValueAt(int aRow, int aColumn) {
Vector row = (Vector)rows.elementAt(aRow);
return row.elementAt(aColumn);
}

public String dbRepresentation(int column, Object value) {
int type;

if (value == null) {
return "null";
}

try {
type = metaData.getColumnType(column+1);
}
catch (SQLException e) {
return value.toString();
}

switch(type) {
case Types.INTEGER:
case Types.DOUBLE:
case Types.FLOAT:
return value.toString();
case Types.BIT:
return ((Boolean)value).booleanValue() ? "1" : "0";
case Types.DATE:
return value.toString(); // This will need some conversion.
default:
return "\""+value.toString()+"\"";
}

}

public void setValueAt(Object value, int row, int column) {
try {
String tableName = metaData.getTableName(column+1);
// Some of the drivers seem buggy, tableName should not be null.
if (tableName == null) {
System.out.println("Table name returned null.");
}
String columnName = getColumnName(column);
String query =
"update "+tableName+
" set "+columnName+" = "+dbRepresentation(column, value)+
" where ";
// We don't have a model of the schema so we don't know the
// primary keys or which columns to lock on. To demonstrate
// that editing is possible, we'll just lock on everything.
for(int col = 0; col String colName = getColumnName(col);
if (colName.equals("")) {
continue;
}
if (col != 0) {
query = query + " and ";
}
query = query + colName +" = "+
dbRepresentation(col, getValueAt(row, col));
}
System.out.println(query);
System.out.println("Not sending update to database");
// statement.executeQuery(query);
}
catch (SQLException e) {
// e.printStackTrace();
System.err.println("Update failed");
}
Vector dataRow = (Vector)rows.elementAt(row);
dataRow.setElementAt(value, column);

}
}