实现：读取文件夹指定类型的文件，并显示到表格控件中。

应用：对于项目开发中的文件分类起到了抛砖引玉的作用。

效果图：

实现代码：

package com.lixiyu;
import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.sql.Date;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.JTextField;
import javax.swing.border.EmptyBorder;
import javax.swing.event.CaretEvent;
import javax.swing.event.CaretListener;
import javax.swing.table.DefaultTableModel;
public class ListCustomTypeFile extends JFrame {/****/private static final long serialVersionUID = -6263975104443132420L;/*** 自定义扩展名过滤器** @author DylanLee*/private final class CustomFilter implements java.io.FileFilter {@Overridepublic boolean accept(File pathname) {// 获取用户设置的指定扩展名String extName = extNameField.getText();if (extName == null || extName.isEmpty())return false;if (!extName.startsWith("."))// 判断扩展名前缀extName = "." + extName;// 完事扩展名前缀extName = extName.toLowerCase();// 判断扩展名与过滤文件名是否符合要求if (pathname.getName().toLowerCase().endsWith(extName))return true;return false;}}private JPanel contentPane;private JTextField extNameField;private JTable table;private File dir;private JLabel label;/*** Launch the application.*/public static void main(String[] args) {EventQueue.invokeLater(new Runnable() {public void run() {try {ListCustomTypeFile frame = new ListCustomTypeFile();frame.setVisible(true);} catch (Exception e) {e.printStackTrace();}}});}/*** Create the frame.*/public ListCustomTypeFile() {setTitle("\u663E\u793A\u6307\u5B9A\u7C7B\u578B\u7684\u6587\u4EF6");setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);setBounds(100, 100, 450, 300);contentPane = new JPanel();contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));contentPane.setLayout(new BorderLayout(0, 0));setContentPane(contentPane);JPanel panel = new JPanel();contentPane.add(panel, BorderLayout.NORTH);GridBagLayout gbl_panel = new GridBagLayout();gbl_panel.columnWidths = new int[] { 93, 54, 0 };gbl_panel.rowHeights = new int[] { 23, 0, 0 };gbl_panel.columnWeights = new double[] { 0.0, 1.0, Double.MIN_VALUE };gbl_panel.rowWeights = new double[] { 0.0, 0.0, Double.MIN_VALUE };panel.setLayout(gbl_panel);JButton button = new JButton("\u9009\u62E9\u6587\u4EF6\u5939");button.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {do_button_actionPerformed(e);}});GridBagConstraints gbc_button = new GridBagConstraints();gbc_button.anchor = GridBagConstraints.NORTH;gbc_button.gridx = 0;gbc_button.gridy = 0;panel.add(button, gbc_button);label = new JLabel("\u6587\u4EF6\u5939");GridBagConstraints gbc_label = new GridBagConstraints();gbc_label.fill = GridBagConstraints.HORIZONTAL;gbc_label.gridx = 1;gbc_label.gridy = 0;panel.add(label, gbc_label);JLabel label_1 = new JLabel("\u8F93\u5165\u6307\u5B9A\u6587\u4EF6\u6269\u5C55\u540D\u79F0\uFF1A");GridBagConstraints gbc_label_1 = new GridBagConstraints();gbc_label_1.anchor = GridBagConstraints.EAST;gbc_label_1.insets = new Insets(0, 0, 0, 5);gbc_label_1.gridx = 0;gbc_label_1.gridy = 1;panel.add(label_1, gbc_label_1);extNameField = new JTextField();extNameField.addCaretListener(new CaretListener() {public void caretUpdate(CaretEvent e) {do_extNameField_caretUpdate(e);}});extNameField.setText(".gif");GridBagConstraints gbc_extNameField = new GridBagConstraints();gbc_extNameField.insets = new Insets(0, 0, 5, 0);gbc_extNameField.fill = GridBagConstraints.HORIZONTAL;gbc_extNameField.gridx = 1;gbc_extNameField.gridy = 1;panel.add(extNameField, gbc_extNameField);extNameField.setColumns(10);JScrollPane scrollPane = new JScrollPane();contentPane.add(scrollPane, BorderLayout.CENTER);table = new JTable();table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);table.setModel(new DefaultTableModel(new Object[][] {}, new String[] {"\u6587\u4EF6\u540D\u79F0", "\u6587\u4EF6\u5927\u5C0F","\u4FEE\u6539\u65E5\u671F" }) {/****/private static final long serialVersionUID = 5274214559103654856L;boolean[] columnEditables = new boolean[] { false, false, false };public boolean isCellEditable(int row, int column) {return columnEditables[column];}});table.getColumnModel().getColumn(0).setPreferredWidth(220);table.getColumnModel().getColumn(1).setPreferredWidth(85);table.getColumnModel().getColumn(2).setPreferredWidth(110);scrollPane.setViewportView(table);}/*** 选择文件夹按钮的事件处理方法** @param e*/protected void do_button_actionPerformed(ActionEvent e) {JFileChooser chooser = new JFileChooser();// 创建文件选择器// 设置选择器的过滤器chooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);chooser.showDialog(this, null);dir = chooser.getSelectedFile();getLabel().setText(dir.toString());// 获取过滤后的符合条件的文件数组listFiles();}/*** 显示文件夹中的文件*/private void listFiles() {if (dir == null)return;// 获取符合条件的文件数组File[] files = dir.listFiles(new CustomFilter());// 获取表格的数据模型DefaultTableModel model = (DefaultTableModel) table.getModel();model.setRowCount(0);for (File file : files) {// 遍历文件数组// 创建表格行数据Object[] row = { file.getName(), file.length(),new Date(file.lastModified()) };model.addRow(row);// 添加行数据到表格模型}}protected void do_extNameField_caretUpdate(CaretEvent e) {listFiles();}protected JLabel getLabel() {return label;}
}