如何解决android中hashmap to string问题

import com.google.gson.Gson;

HashMap<String, String> hashMap = new HashMap<>();
// 添加键值对到HashMap

// 将HashMap转换为JSON字符串
Gson gson = new Gson();
String jsonString = gson.toJson(hashMap);

// 将JSON字符串转换为字符串
String result = jsonString.toString();

HashMap<String, String> hashMap = new HashMap<>();
// 添加键值对到HashMap

StringBuilder stringBuilder = new StringBuilder();
for (Map.Entry<String, String> entry : hashMap.entrySet()) {
    stringBuilder.append(entry.getKey()).append(": ").append(entry.getValue()).append("\n");
}

String result = stringBuilder.toString();