如何在java中比较两个txt文件中的元素并将其合并为一个文件？

import java.io.*;
import java.util.ArrayList;
import java.util.List;

public class MergeTxtFiles {
    public static void main(String[] args) {
        String file1Path = "file1.txt";
        String file2Path = "file2.txt";
        String mergedFilePath = "merged.txt";

        List<String> file1Lines = readFileLines(file1Path);
        List<String> file2Lines = readFileLines(file2Path);

        List<String> mergedLines = mergeLines(file1Lines, file2Lines);

        writeToFile(mergedFilePath, mergedLines);
    }

    private static List<String> readFileLines(String filePath) {
        List<String> lines = new ArrayList<>();
        try (BufferedReader reader = new BufferedReader(new FileReader(filePath))) {
            String line;
            while ((line = reader.readLine()) != null) {
                lines.add(line);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return lines;
    }

    private static List<String> mergeLines(List<String> lines1, List<String> lines2) {
        List<String> mergedLines = new ArrayList<>();
        for (String line : lines1) {
            if (lines2.contains(line)) {
                mergedLines.add(line);
            }
        }
        return mergedLines;
    }

    private static void writeToFile(String filePath, List<String> lines) {
        try (BufferedWriter writer = new BufferedWriter(new FileWriter(filePath))) {
            for (String line : lines) {
                writer.write(line);
                writer.newLine();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}