A way to replace srg names with mcp names in arbitrary files, as long as they are separated by spaces

CrudeDeobf.java

package malte0811.crudedeobf;

import java.io.*;
import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;
import java.util.StringTokenizer;

public class CrudeDeobf
{
	public static void main(String[] args) throws Exception
	{
		File in = new File("srg-mcp.srg");
		File replayIn = new File("run/replay_half.log");
		File replayOut = new File("run/replay.log");
		Map<String, String> names = new HashMap<>();
		readNames(in, names);
		process(new FileInputStream(replayIn), new FileOutputStream(replayOut), names);
	}

	public static void readNames(File in, Map<String, String> names) throws FileNotFoundException
	{
		Scanner s = new Scanner(in);
		while (s.hasNextLine()) {
			String line = s.nextLine();
			if (line.startsWith("FD")) {
				processLine(line, names, 0);
			} else if (line.startsWith("MD")) {
				processLine(line, names, 1);
			}
		}
	}

	private static void processLine(String line, Map<String, String> output, int skip) {
		StringTokenizer tok = new StringTokenizer(line);
		tok.nextToken();//MD/FD
		String nameFull = tok.nextToken();
		String srg = nameFull.substring(nameFull.lastIndexOf('/')+1);
		for (int i = 0; i < skip; i++)
		{
			tok.nextToken();//Skip signature if present
		}
		String deobfFull = tok.nextToken();
		String mcp = deobfFull.substring(nameFull.lastIndexOf('/')+1);
		output.put(srg, mcp);
	}

	public static void process(InputStream input, OutputStream output, Map<String, String> replacements) throws IOException
	{
		boolean done = false;
		while (!done) {
			int c;
			while ((c = input.read())>=0&&Character.isWhitespace(c)) {
				output.write(c);
			}
			if (c<=0) {
				return;
			}
			StringBuilder token = new StringBuilder("" + (char) c);
			while ((c = input.read())>=0&&!Character.isWhitespace(c)) {
				token.append((char) c);
			}
			String read = token.toString();
			read = replacements.getOrDefault(read, read);
			output.write(read.getBytes());
			if (c>=0) {
				output.write(c);
			} else {
				done = true;
			}
		}
	}
}