如何将一个Map中的K和另一个Map中的V写入一个文件？

import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

public class MapToFileWriter {
    public static void main(String[] args) {
        Map<String, String> map1 = new HashMap<>();
        map1.put("key1", "value1");
        map1.put("key2", "value2");
        map1.put("key3", "value3");

        Map<String, String> map2 = new HashMap<>();
        map2.put("key1", "file1");
        map2.put("key2", "file2");
        map2.put("key3", "file3");

        String filePath = "output.txt";

        try (BufferedWriter writer = new BufferedWriter(new FileWriter(filePath))) {
            for (Map.Entry<String, String> entry : map1.entrySet()) {
                String key = entry.getKey();
                String value = entry.getValue();

                if (map2.containsKey(key)) {
                    String fileValue = map2.get(key);
                    writer.write(key + "," + value + "," + fileValue);
                    writer.newLine();
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}