无法将Retrofit List转换为字符串

public interface ApiService {
    @GET("your/api/endpoint")
    Call<List<DataModel>> getData();
}

ApiService apiService = retrofit.create(ApiService.class);
Call<List<DataModel>> call = apiService.getData();
call.enqueue(new Callback<List<DataModel>>() {
    @Override
    public void onResponse(Call<List<DataModel>> call, Response<List<DataModel>> response) {
        if (response.isSuccessful()) {
            List<DataModel> data = response.body();
            // 将List转换为字符串
            String dataString = convertListToString(data);
            // 处理或展示字符串数据
            // ...
        } else {
            // 处理请求失败的情况
            // ...
        }
    }

    @Override
    public void onFailure(Call<List<DataModel>> call, Throwable t) {
        // 处理请求失败的情况
        // ...
    }
});

private String convertListToString(List<DataModel> data) {
    StringBuilder stringBuilder = new StringBuilder();
    for (DataModel item : data) {
        stringBuilder.append(item.toString());
        stringBuilder.append("\n");
    }
    return stringBuilder.toString();
}