espantos

import java.io.*;

public class CharCleaner {

	public static void main(String[] args) throws IOException {


		try (
				Reader reader = new BufferedReader(new FileReader(new File("sourceFile.txt")));
				Writer writer = new BufferedWriter(new FileWriter(new File("resultFile.txt")))
		) {

			int ch;

			while ((ch = reader.read()) != -1) {
				if (Character.isAlphabetic(ch)) {
					writer.write(ch);
				}
			}


			writer.flush();
		} catch (IOException e) {
			e.printStackTrace();
		}

	}

}