【Java17】06 SwingによるGUIアプリ作成 ボタンのアクション設定

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.JButton;
import javax.swing.JRadioButton;
import javax.swing.JTextArea;
import java.awt.GridBagLayout;
import java.awt.GridBagConstraints;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.Color;
import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.stream.Stream;
import java.util.List;
import java.util.Arrays;
import java.util.stream.Collectors;

public class App extends JPanel{
    private JLabel lbl = new JLabel("PATH");
    private JTextField tfield = new JTextField();
    private JButton btn1 = new JButton("削除");
    private JButton btn2 = new JButton("クリア");
    private JTextArea area = new JTextArea();

	Color lemonchiffon = new Color(0xfffacd);
	int lemonchiffon_red = lemonchiffon.getRed();
	int lemonchiffon_green = lemonchiffon.getGreen();
	int lemonchiffon_blue = lemonchiffon.getBlue();

    public App(){
        GridBagLayout layout = new GridBagLayout();
        this.setLayout(layout);

        GridBagConstraints constraints = new GridBagConstraints();
        constraints.fill = GridBagConstraints.BOTH;
		constraints.insets = new Insets(2, 5, 2, 5);

        constraints.gridx = 0;	//位置x
		constraints.gridy = 0;	//位置y
		constraints.gridwidth = 1;	//コンポーネントの表示領域のセル数 横
		constraints.gridheight = 1;	//コンポーネントの表示領域のセル数 縦
		layout.setConstraints(lbl, constraints);
		this.add(lbl);

        constraints.gridx = 1;
		constraints.gridy = 0;
		constraints.gridwidth = 2;
		constraints.gridheight = 1;
		constraints.weightx = 1;
		tfield.setBackground(new Color(lemonchiffon_red,lemonchiffon_green,lemonchiffon_blue));
		layout.setConstraints(tfield, constraints);
		this.add(tfield);

        constraints.gridx = 3;
		constraints.gridy = 0;
		constraints.gridwidth = 1;
		constraints.gridheight = 1;
		constraints.weightx = 0;
		layout.setConstraints(btn1, constraints);
		this.add(btn1);

		btn1.addActionListener(new ActionListener() {
			@Override
			public void actionPerformed(ActionEvent e) {
				String str = tfield.getText();
				try{
					Stream<Path> list = Files.walk(Paths.get(str));
					Path[] array = list.toArray(Path[]::new);
					List<Path> list2 = Arrays.asList(array);

					for(int i=0; i<list2.size(); i++) {
						Path p = Paths.get(list2.get(i).toString());
						if (Files.isDirectory(p)){
							;
						}else{
							try{
								Files.delete(list2.get(i));
							}catch(IOException e2) {
								System.out.println(e2);
							}
						}
					}

					list.close();

				}catch(IOException e1) {
					System.out.println(e1);
				}
			}
		});
        
        constraints.gridx = 3;
		constraints.gridy = 1;
		constraints.gridwidth = 1;
		constraints.gridheight = 1;
		layout.setConstraints(btn2, constraints);
		this.add(btn2);

		btn2.addActionListener(new ActionListener() {
			@Override
			public void actionPerformed(ActionEvent e) {
				tfield.setText("");
			}
		});

		constraints.gridx = 0;
		constraints.gridy = 2;
		constraints.gridwidth = 4;
		constraints.gridheight = 1;
		constraints.weighty = 1;
		area.setBackground(new Color(lemonchiffon_red,lemonchiffon_green,lemonchiffon_blue));
		layout.setConstraints(area, constraints);
		this.add(area);
    }
    public static void main(String[] args){
        JFrame frm = new FrameGridLayout();
		frm.setBounds(100, 100, 350, 200);
	}
}

class FrameGridLayout extends JFrame{
	Color palegreen = new Color(0x98fb98);
	int palegreen_red = palegreen.getRed();
	int palegreen_green = palegreen.getGreen();
	int palegreen_blue = palegreen.getBlue();

    public FrameGridLayout(){
		this.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
		this.setTitle("FILE REMOVER JV v0.0.1");
		JPanel panel = new App();
		panel.setBackground(new Color(palegreen_red,palegreen_green,palegreen_blue));
		this.setContentPane(panel);
		this.setVisible(true);
    }
}