java基础：高级GUI组件之表格

1、JTable类生成的对象以该TableModel为参数，并负责将TableModel对象中的数据以表格的形式显示出业。
2、程序演示：

// 程序来源：机械工业出版社《Java面向对象编程》葛志春等编著
     import  javax.swing. * ;
import  java.awt.event. * ;
import  java.awt. * ;
import  java.util.Calendar;
import  java.util.Date;
/** */ /***日历类,提供日历功能*/
public   class  TableDemo  extends  JPanel  implements  
ActionListener,MouseMotionListener,MouseListener {
    final private String TITLES[]={"星期日","星期一","星期二","星期三","星期四",
            "星期五","星期六"};
    final private int ROW_HEIGHT=20;
    final private int ROW_WIDTH=40;
    private JTable tbMain;//表格
    private JLabel lblTitle;//标题
    private JButton btnNextMonth;//下个月的按钮
    private JButton btnPrevMonth;//上个月的按钮
    private JPanel pnlTop;//顶部容器
    private int year;//当前显示的年份
    private int month;//当前显示的月份
    private int day;//当前选择的日期
    private int week;//当前选择的星期
    private int selectedX=-1;
    private int selectedY=-1;
    private int clickX=-1;
    private int clickY=-1;
    public TableDemo(){
        Calendar cal=Calendar.getInstance();
        cal.setTime(new Date());
        year=cal.get(Calendar.YEAR);
        month=cal.get(Calendar.MONTH)+1;
        day=cal.get(Calendar.DAY_OF_MONTH)-1;
        week=cal.get(Calendar.DAY_OF_WEEK)-1;
        pnlTop=new JPanel(new FlowLayout(FlowLayout.CENTER));
        tbMain=new JTable(7,7);
        tbMain.setPreferredSize(new Dimension(ROW_WIDTH*7,ROW_HEIGHT*7));
        tbMain.setRowHeight(ROW_HEIGHT);
        for(int i=0;i<TITLES.length;i++)
            tbMain.setValueAt(TITLES[i], 0, i);
        tbMain.addMouseMotionListener(this);
        tbMain.addMouseListener(this);
        tbMain.setEnabled(false);
        tbMain.setCellSelectionEnabled(true);
        lblTitle=new JLabel();
        btnNextMonth=new JButton(">|");
        btnNextMonth.addActionListener(this);
        btnPrevMonth=new JButton("|<");
        btnPrevMonth.addActionListener(this);
        pnlTop.add(btnPrevMonth);
        pnlTop.add(lblTitle);
        pnlTop.add(btnNextMonth);
        setTheTitle();
        //布局组件
        setLayout(new BorderLayout());
        add(pnlTop,BorderLayout.NORTH);
        add(tbMain,BorderLayout.CENTER);
        showMonth();//设置当前月份
    }
    //取得指定年份和月份的日期数
    public int getDaysofMonth(int year,int month){
        int Days[]={31,28,31,30,31,30,31,31,30,31,30,31};
        //判断是否闰年
        if(year%400==0||(year%4==0&&year%100!=0))
            Days[1]=29;
        return Days[month-1];
    }
    //取得指定月份的头一天是星期几
    public int getWeekOfFirstDay(int year,int month){
        Calendar cal=Calendar.getInstance();
        cal.set(Calendar.YEAR, year);
        cal.set(Calendar.MONTH, month-1);
        cal.set(Calendar.DAY_OF_MONTH, 1);
        int result=cal.get(Calendar.DAY_OF_WEEK)-1;
        return result;
    }
    //设置显示的标题
    private void setTheTitle(){
        String m=String.valueOf(month);
        if(m.length()==1)m="0"+m;
        lblTitle.setText(String.valueOf(year)+"年"+m+"月");
    }
    //显示月份
    private void showMonth(){
        for(int x=0;x<7;x++)
            for(int y=1;y<7;y++)tbMain.setValueAt(" ",y, x);
        int y=1;
        int x=getWeekOfFirstDay(year,month);
        int maxDay=getDaysofMonth(year,month);
        for(int i=0;i<maxDay;i++){
            tbMain.setValueAt(new Integer(i+1),y,x);
            x++;
            if(x>6){
                x=0;
                y++;
            }
        }
        repaint();
    }
    //按钮事件处理
    public void actionPerformed(ActionEvent e){
        if(e.getSource().equals(btnNextMonth)){
            month++;
            if(month>12){
                month=1;
                year++;
            }
        }
        if(e.getSource().equals(btnPrevMonth)){
            month--;
            if(month<1){
                month=12;
                year--;
            }
        }
        setTheTitle();
        showMonth();
    }
    //绘制
    public void paint(Graphics g){
        super.paint(g);
        //repaint Table First LINE
        g.fillRect(0,pnlTop.getHeight(),getWidth()-1,ROW_HEIGHT-1);
        g.setColor(Color.white);
        for(int i=0;i<7;i++)
            g.drawString((String)(tbMain.getModel().getValueAt(0,i)),
                    i*ROW_WIDTH,pnlTop.getHeight()+ROW_HEIGHT-3);
        Calendar cal=Calendar.getInstance();
        cal.set(Calendar.YEAR,year);
        cal.set(Calendar.MONTH,month);
        cal.set(Calendar.DAY_OF_WEEK_IN_MONTH,day);
        int line=cal.get(Calendar.DAY_OF_WEEK_IN_MONTH)+1;
        int x=week*tbMain.getWidth()/7;
        int y=pnlTop.getHeight()+ROW_HEIGHT*line;
        g.setColor(Color.black);
        g.drawRect(x+1,y+1, ROW_WIDTH-4,ROW_HEIGHT-4);
        if(selectedX>0&&selectedY>=0&&!
                tbMain.getModel().getValueAt(clickY,clickX).equals(" ")){
            g.setColor(Color.green);
            g.drawRect(clickX*ROW_WIDTH+1,(clickY+2)*ROW_HEIGHT-1,
                    ROW_WIDTH-4,ROW_HEIGHT-4);
        }
    }
    public void mouseDragged(MouseEvent e){}
    public void mouseMoved(MouseEvent e){}
    public void mouseClicked(MouseEvent e){
        if (e.getX() > 0 && e.getY() < getWidth() && e.getY() > ROW_HEIGHT
                && e.getY() < ROW_HEIGHT * 7) {
            selectedX = e.getX() / ROW_WIDTH;
            selectedY = e.getY() / ROW_HEIGHT;
            repaint();
        }
    }
    public void mousePressed(MouseEvent e){
        if(e.getX()>0&&e.getY()<getWidth()&&
                e.getY()>ROW_HEIGHT&&e.getY()<ROW_HEIGHT*7){
            clickX=e.getX()/ROW_WIDTH;
            clickY=e.getY()/ROW_HEIGHT;
            repaint();
        }
    }
    public void mouseReleased(MouseEvent e){}
    public void mouseEntered(MouseEvent e){}
    public void mouseExited(MouseEvent e){}
    public static void main(String[] args) {
        JFrame frm=new JFrame();
        frm.getContentPane().setLayout(new BorderLayout());
        frm.getContentPane().add(new TableDemo());
        frm.setTitle("表格演示");
        frm.pack();
        frm.setVisible(true);
    }
}