窗体上有一JTable，如何让数据库里的数据在表格里显示出来

找了点代码，学习中
import java.awt.*;
import javax.swing.*;
import javax.swing.table.TableColumn;

public class tableUI extends JPanel

{
public tableUI(String databaseName, String tableName, String[] colNames,
int[] colWidth, int totalWidth) {
try {
Class.forName("org.gjt.mm.mysql.Driver");
} catch (ClassNotFoundException e) {
System.out.println(e);
}
tableHandler = new TableHandler(databaseName, tableName, colNames);
tableHandler.updateTable();
TableColumn column = null;
table = new JTable(tableHandler);
table
.setPreferredScrollableViewportSize(new Dimension(totalWidth,
210));
table.setAutoResizeMode(JTable.AUTO_RESIZE_SUBSEQUENT_COLUMNS);

for (int i = 0; i < colWidth.length; i++) {

column = table.getColumnModel().getColumn(i);

column.setPreferredWidth(colWidth[i] * 100);

}

JScrollPane s = new JScrollPane(table);
this.add(s, BorderLayout.CENTER);
this.setSize(this.getPreferredSize());
setVisible(true);
}

JTable table;

JScrollPane scrollPane;

public TableHandler tableHandler;

}

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import javax.swing.table.AbstractTableModel;

public class TableHandler extends AbstractTableModel {
public TableHandler(String databaseName, String tableName, String[] colNames) {
super();
this.tableName = tableName;
this.databaseName = databaseName;
colNum = colNames.length;
this.colNames = new String[colNum];
System.arraycopy(colNames, 0, this.colNames, 0, colNum);
}

public void updateTable() {
try {
Connection conn;

conn = DriverManager.getConnection("jdbc:mysql://localhost/"
+ databaseName + "?user=root&password=");

Statement myStatement = conn.createStatement();
ResultSet rt = myStatement.executeQuery("SELECT count(*) FROM "
+ tableName);
rt.next();
rowNum = rt.getInt(1);
list = new String[rowNum][colNum];
ResultSet rs = myStatement.executeQuery("SELECT * FROM "
+ tableName);

int row = 0;
while (rs.next()) {
for (int i = 0; i < colNum; i++) {
list[row][i] = rs.getString(colNames[i]);
}
row++;
}
conn.close();
fireTableDataChanged();
} catch (SQLException e) {
System.out.println(e);
}
}

public int getColumnCount() {
return colNum;
}

public int getRowCount() {
return rowNum;
}

public String getColumnName(int col) {
return colNames[col];
}

public Object getValueAt(int row, int column) {
return list[row][column];
}
String[][] list;
String[] colNames;
String tableName;
String databaseName;
int rowNum;
int colNum;
}
代码2：
import java.awt.*;
import java.util.Vector;
import javax.swing.*;
import javax.swing.table.*;

/**
* TableQueryFrame extends JInternalFrame to create a display which builds SQL
* CREATE statements
*/

class TableQueryFrame extends JInternalFrame
{
JTable table;
JScrollPane tableScroller;
DatabaseUtilities dbUtils;

String tableName = null;
String colNames[] = null;
String dataTypes[] = null;
String SQLQuery = null;

public TableQueryFrame(String tableName, DatabaseUtilities dbUtils)
{
setSize(450,300);
setClosable(true);
setMaximizable(true);
setIconifiable(true);
setResizable(true);
getContentPane().setLayout(new BorderLayout());
this.tableName=tableName;
this.dbUtils=dbUtils;

colNames = dbUtils.getColumnNames(tableName);
dataTypes = dbUtils.getDataTypes(tableName);
SQLQuery = "SELECT TOP 5 * FROM "+tableName;
Vector dataSet = dbUtils.executeQuery(SQLQuery);
table = createTable(colNames,dataSet);
tableScroller = new JScrollPane(table);
getContentPane().add(tableScroller,BorderLayout.CENTER);

setVisible(true);
}

JTable createTable(String[] colNames,Vector dataSet)
{
int nRows = dataSet.size();
String[][] rowData = new String[nRows][colNames.length];
for(int i=0;i<nRows;i++)
{
Vector row = (Vector)dataSet.elementAt(i);
for(int j=0;j<row.size();j++)
rowData[i][j]=((Object)row.elementAt(j)).toString();
}
JTable table = new JTable(rowData,colNames);
return table;
}
}