Writes to a file, reads from a file, and searches and replaces words in the file and rewrites to the file.

SearchAndReplace.java

import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.nio.charset.StandardCharsets;
import java.nio.file.FileSystems;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.List;

public class Main {

	static PrintWriter writer;
	static List<String> lines;
	
	public static void main(String[] args) throws IOException {
		
		createFile();
		writetofile("Apple");
		writetofile("Microsoft");
		writetofile("Facebook");
		readFile();
		
		System.out.println(lines);
		
		writetofile("Yahoo!!");
		readFile();
		System.out.println(lines);
		
		
		searchAndReplace("Yahoo", "Google");
		readFile();
		
		System.out.println(lines);
		
		closefile();
		
	}
	
	public static void writetofile () {
		writer.flush();
	}

	
	public static void writetofile (String texttoadd) {
		writer.println(texttoadd);
		writer.flush();
	}

	public static void createFile () throws FileNotFoundException, UnsupportedEncodingException {
		writer = new PrintWriter("E:\\=== USUARIO BORN ===\\Desktop\\the-file-name.txt", "UTF-8");
	}
	
	private static void readFile() throws IOException {
		Path path = FileSystems.getDefault().getPath("E:\\=== USUARIO BORN ===\\Desktop\\the-file-name.txt");
		lines = Files.readAllLines(path, StandardCharsets.UTF_8);
	}
	
	private static void closefile() {
	writer.close();
	}
	
	private static void searchAndReplace(String toSearch, String toReplace) throws IOException {
		readFile();
		createFile();
		
		for (int i = 0; i < lines.size(); i++) {
			String aString=lines.get(i);
			writetofile(aString.replaceAll(toSearch, toReplace));
			writer.flush();
		}	
	}
}