在JTable中动态加载大量数据

Question

这是我的问题:我目前有一个JTable,包含5,000到200,000多行.你知道我要去哪里.数据已经加载到内存中,这不是问题,但是我如何创建一个高效的JTable,以便它只加载可见的行,并且任何事件只对视口中可见的那些行起作用？显然,使用这么多数据滚动几乎是不可能的,因为系统需要永远重新绘制和触发事件.

基本上我认为一种解决方案是确定哪些行在视口中,然后创建一个包含这些行的新模型呢？

Answer 1

您可以使用FixedRowsTable类型设计,此处显示一些200,000行.虽然你想添加额外的按钮 << >>

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.table.*;

class FixedRowsTable {

    public static void main(String[] args) {

        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                String[] columns = {"1","2","3","4","5","6","7"};
                Integer[][] data = new Integer[200000][columns.length];
                for (int xx=0; xx<data.length; xx++) {
                    for (int yy=0; yy<data[0].length; yy++) {
                        data[xx][yy] = new Integer((xx+1)*(yy+1));
                    }
                }
                final int rows = 11;

                JPanel gui = new JPanel(new BorderLayout(3,3));

                final JTable table = new JTable(
                    new DefaultTableModel(data, columns));

                final JScrollPane scrollPane = new JScrollPane(
                    table,
                    JScrollPane.VERTICAL_SCROLLBAR_NEVER,
                    JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
                Dimension d = table.getPreferredSize();
                scrollPane.setPreferredSize(
                    new Dimension(d.width,table.getRowHeight()*rows));

                JPanel navigation = new JPanel(
                    new FlowLayout(FlowLayout.CENTER));
                JButton next = new JButton(">");
                next.addActionListener( new ActionListener(){
                    public void actionPerformed(ActionEvent ae) {
                        int height = table.getRowHeight()*(rows-1);
                        JScrollBar bar = scrollPane.getVerticalScrollBar();
                        bar.setValue( bar.getValue()+height );
                    }
                } );
                JButton previous = new JButton("<");
                previous.addActionListener( new ActionListener(){
                    public void actionPerformed(ActionEvent ae) {
                        int height = table.getRowHeight()*(rows-1);
                        JScrollBar bar = scrollPane.getVerticalScrollBar();
                        bar.setValue( bar.getValue()-height );
                    }
                } );

                navigation.add(previous);
                navigation.add(next);

                gui.add(scrollPane, BorderLayout.CENTER);
                gui.add(navigation, BorderLayout.SOUTH);

                JOptionPane.showMessageDialog(null, gui);
            }
        });
    }
}