如何将hashMap转换为Json文件

   <groupId>com.fasterxml.jackson.core</groupId>
   <artifactId>jackson-databind</artifactId>
   <version>2.13.0</version>
</dependency>

import com.fasterxml.jackson.databind.ObjectMapper;
import java.io.File;
import java.io.IOException;
import java.util.HashMap;

public class HashMapToJsonExample {
    public static void main(String[] args) {
        HashMap<String, String> hashMap = new HashMap<>();
        hashMap.put("key1", "value1");
        hashMap.put("key2", "value2");

        ObjectMapper objectMapper = new ObjectMapper();
        try {
            objectMapper.writeValue(new File("output.json"), hashMap);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

   <groupId>com.google.code.gson</groupId>
   <artifactId>gson</artifactId>
   <version>2.8.9</version>
</dependency>

import com.google.gson.Gson;
import java.io.FileWriter;
import java.io.IOException;
import java.util.HashMap;

public class HashMapToJsonExample {
    public static void main(String[] args) {
        HashMap<String, String> hashMap = new HashMap<>();
        hashMap.put("key1", "value1");
        hashMap.put("key2", "value2");

        Gson gson = new Gson();
        try {
            FileWriter writer = new FileWriter("output.json");
            gson.toJson(hashMap, writer);
            writer.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}