org.eclipse.epsilon.egl.patch.FilePatcher Maven / Gradle / Ivy

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/*********************************************************************
* Copyright (c) 2008 The University of York.
*
* This program and the accompanying materials are made
* available under the terms of the Eclipse Public License 2.0
* which is available at https://www.eclipse.org/legal/epl-2.0/
*
* SPDX-License-Identifier: EPL-2.0
**********************************************************************/
package org.eclipse.epsilon.egl.patch;

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.FileWriter;
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;

/**
 * 
 * @since 1.6
 */
public class FilePatcher {
	
	public static void main(String[] args) throws Exception {
		if (args.length != 3) {
			System.out.println("Usage: java -jar filepatcher.jar inputfile patchfile outputfile");
		}
		new FilePatcher().run(args[0], args[1], args[2]);
	}
	
	public void run(String inputPath, String patchPath, String targetPath) throws Exception {
		
		TextBlock input = new TextBlock(readFromPath(inputPath));
		Patch patch = new Patch(readFromPath(patchPath));
		if (!patch.validate().isEmpty()) throw new Exception("Invalid patch");
		TextBlock output = patch.apply(input);
		
		try (FileWriter targetWriter = new FileWriter(targetPath)) {
			String joined = output.getLines().stream()
				.map(Line::getText)
				.collect(Collectors.joining(System.lineSeparator()));
			
			targetWriter.write(joined);
		}
	}
	
	protected String[] readFromPath(String path) throws Exception {
		try (BufferedReader bufferedReader = new BufferedReader(new FileReader(path))) {
			List lines = new ArrayList<>();
			for (String line = null; (line = bufferedReader.readLine()) != null; lines.add(line));
			return lines.toArray(new String[lines.size()]);
		}
	}
	
}