ANTLR is a powerful parser generator for multiple programming languages including Java.

ANTLR contains 2 major modules:

• Runtime - For building and executing parsers/lexers generated in Java.
• Tool (The Parser Generator) - For generating parsers/lexers Java class.

ANTLR Tool Source Code files are provided in the distribution packge (antlr4-4.10.1.zip). You can download them at ANTLR Website.

You can also browse the source code below:

⏎ org/antlr/v4/gui/JFileChooserConfirmOverwrite.java

/*
 * Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
 * Use of this file is governed by the BSD 3-clause license that
 * can be found in the LICENSE.txt file in the project root.
 */
package org.antlr.v4.gui;

import javax.swing.*;
import java.io.File;

/**
 *
 * @author Sam Harwell
 */
public class JFileChooserConfirmOverwrite extends JFileChooser {

	public JFileChooserConfirmOverwrite() {
		setMultiSelectionEnabled(false);
	}

	@Override
	public void approveSelection() {
		File selectedFile = getSelectedFile();

		if (selectedFile.exists()) {
			int answer = JOptionPane.showConfirmDialog(this,
													   "Overwrite existing file?",
													   "Overwrite?",
													   JOptionPane.YES_NO_OPTION);
			if (answer != JOptionPane.YES_OPTION) {
				// do not call super.approveSelection
				return;
			}
		}

		super.approveSelection();
	}

}

⏎ org/antlr/v4/gui/JFileChooserConfirmOverwrite.java

Or download all of them as a single archive file:

File name: antlr-tool-4.10.1-sources.jar
File size: 347718 bytes
Release date: 2022-04-15
Download 

⇒ Donwload antlr4-4.10.1.zip

⇐ ANTLR Runtime Source Code

⇑ Download and Review ANTLR Parser Generator

⇑⇑ FAQ for ANTLR Parser Generator