java我该如何向表格中填写内容？

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.HeadlessException;

import javax.swing.*;

public class JTableTest extends JFrame {
private JTable table;

public static void main(String[] args) {
    JTableTest frame = new JTableTest();
    frame.setVisible(true);
}

public JTableTest() {
    super();
    setTitle("操作表格");// 窗体名称
    setBounds(200, 200, 1000, 740);// 窗体大小
    setDefaultCloseOperation(EXIT_ON_CLOSE);
    Container c = getContentPane();

    String[] columnNames = { "A", "B", "C", "D", "E", "F", "G" };// 定义表格列
    String[][] tableValues = new String[20][columnNames.length];// 定义数组，用来存储表格数据

    for (int row = 0; row < tableValues.length; row++) {
        for (int column = 0; column < columnNames.length; column++) {
            tableValues[row][column] = columnNames[column] + row;// 给表格赋值
        }
    }
    JTable table = new JTable(tableValues, columnNames);
    JScrollPane sc = new JScrollPane(table);
    c.add(table, BorderLayout.CENTER);

    table.setSelectionForeground(Color.RED);// 设置前景色，字体颜色
    table.setBackground(Color.PINK);
    table.setSelectionBackground(Color.yellow);// 背景色
    table.setRowHeight(30);// 设置行高30像素
    /*
     * ListSelectionModel.SINGLE_SELECTION 单选
     */
    table.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);// 选择模式

    System.out.println("表格共有" + table.getRowCount() + "行" + table.getColumnCount() + "列");

}

}

把它自动生成A0，A1这些换成别的内容怎么换