Java表格JTable代码实例解析

import javax.swing.JTable;
import javax.swing.table.AbstractTableModel;
import javax.swing.JScrollPane;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import java.awt.*;
import java.awt.event.*;

public class JTableDemo extends JFrame {
  private boolean DEBUG = true;

  public JTableDemo() { // 实现构造方法
    super("RecorderOfWorkers"); // 首先调用父类JFrame的构造方法生成一个窗口
    MyTableModel myModel = new MyTableModel();// myModel存放表格的数据
    JTable table = new JTable(myModel);// 表格对象table的数据来源是myModel对象
    table.setPreferredScrollableViewportSize(new Dimension(500, 70));// 表格的显示尺寸

    // 产生一个带滚动条的面板
    JScrollPane scrollPane = new JScrollPane(table);

    // 将带滚动条的面板添加入窗口中
    getContentPane().add(scrollPane, BorderLayout.CENTER);

    addWindowListener(new WindowAdapter() {// 注册窗口监听器
      public void windowClosing(WindowEvent e) {
        System.exit(0);
      }
    });
  }

  // 把要显示在表格中的数据存入字符串数组和Object数组中
  class MyTableModel extends AbstractTableModel {
    // 表格中第一行所要显示的内容存放在字符串数组columnNames中
    final String[] columnNames = { "First Name", "Position", "Telephone",
        "MonthlyPay", "Married" };
    // 表格中各行的内容保存在二维数组data中
    final Object[][] data = {
        { "Wangdong", "Executive", "01068790231", new Integer(5000),
            new Boolean(false) },
        { "LiHong", "Secretary", "01069785321", new Integer(3500),
            new Boolean(true) },
        { "LiRui", "Manager", "01065498732", new Integer(4500),
            new Boolean(false) },
        { "ZhaoXin", "Safeguard", "01062796879", new Integer(2000),
            new Boolean(true) },
        { "ChenLei", "Salesman", "01063541298", new Integer(4000),
            new Boolean(false) } };

    // 下述方法是重写AbstractTableModel中的方法，其主要用途是被JTable对象调用，以便在表格中正确的显示出来。程序员必须根据采用的数据类型加以恰当实现。

    // 获得列的数目
    public int getColumnCount() {
      return columnNames.length;
    }

    // 获得行的数目
    public int getRowCount() {
      return data.length;
    }

    // 获得某列的名字，而目前各列的名字保存在字符串数组columnNames中
    public String getColumnName(int col) {
      return columnNames[col];
    }

    // 获得某行某列的数据，而数据保存在对象数组data中
    public Object getValueAt(int row, int col) {
      return data[row][col];
    }

    // 判断每个单元格的类型
    public Class getColumnClass(int c) {
      return getValueAt(0, c).getClass();
    }

    // 将表格声明为可编辑的
    public boolean isCellEditable(int row, int col) {

      if (col < 2) {
        return false;
      } else {
        return true;
      }
    }

    // 改变某个数据的值
    public void setValueAt(Object value, int row, int col) {
      if (DEBUG) {
        System.out.println("Setting value at " + row + "," + col
            + " to " + value + " (an instance of "
            + value.getClass() + ")");
      }

      if (data[0][col] instanceof Integer && !(value instanceof Integer)) {
        try {
          data[row][col] = new Integer(value.toString());
          fireTableCellUpdated(row, col);
        } catch (NumberFormatException e) {
          JOptionPane.showMessageDialog(JTableDemo.this, "The \""
              + getColumnName(col)
              + "\" column accepts only integer values.");
        }
      } else {
        data[row][col] = value;
        fireTableCellUpdated(row, col);
      }

      if (DEBUG) {
        System.out.println("New value of data:");
        printDebugData();
      }
    }

    private void printDebugData() {
      int numRows = getRowCount();
      int numCols = getColumnCount();

      for (int i = 0; i < numRows; i++) {
        System.out.print(" row " + i + ":");
        for (int j = 0; j < numCols; j++) {
          System.out.print(" " + data[i][j]);
        }
        System.out.println();
      }
      System.out.println("--------------------------");
    }
  }

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