java - 我的 JSON 输出有什么问题？ retrofit.converter.ConversionException 异常

Question

我正在尝试对一些 json 使用 retro fit，但看不到我的 json 字符串有什么问题，我不断收到同样的错误。

我期待一个单词对象列表，但我错过了什么？有什么想法吗？

retrofit.converter.ConversionException: com.google.gson.JsonSyntaxException: java.lang.IllegalStateException: Expected BEGIN_ARRAY but was BEGIN_OBJECT at line 1 column 2 path $

JSON:

{
    "words": [
        {
            "id": "1",
            "word": "submarine",
            "word_syllables": "sub-mar-ine",
            "picture": "none.jpg",
            "picture_dir": "",
            "soundfile": "",
            "user_id": "1",
            "created": "2015-04-08 16:32:07",
            "modified": "0000-00-00 00:00:00"
        },
        {
            "id": "2",
            "word": "computer",
            "word_syllables": "com-pute-r",
            "picture": "computer.jpg",
            "picture_dir": "",
            "soundfile": "",
            "user_id": "0",
            "created": "2015-04-08 16:32:07",
            "modified": "0000-00-00 00:00:00"
        }
    ]
}

改造安卓代码:

private void requestData(){

    RestAdapter adapter=new RestAdapter.Builder()
    .setEndpoint(ENDPOINT)
    .build();

    WordsAPI api=adapter.create(WordsAPI.class);

    api.getRestWordFeed(new Callback<List<Word>>(){

            @Override
            public void failure(RetrofitError arg0) {
                // TODO Auto-generated method stub
                Log.v("error",arg0.getMessage());
            }

            @Override
            public void success(List arg0, Response arg1) {
                // TODO Auto-generated method stub  
                wordList=arg0;
                printList();                    
            }
    });

}

API接口(interface):

package com.example.testretrofitlib;

import java.util.List;

import retrofit.Callback;
import retrofit.http.GET;

public interface WordsAPI { 

    @GET("/rest_words/index.json")
    public void getRestWordFeed(Callback<List<Word>> response);


}

Answer 1

您的 JSON 是一个具有一个属性的对象:'words'，它是一个单词对象数组。您的错误:“Expected BEGIN_ARRAY but was BEGIN_OBJECT”表示您需要一个数组，但返回了一个对象。一种解决方案是将以下内容作为 json 返回:

[
    {
        "id": "1",
        "word": "submarine",
        "word_syllables": "sub-mar-ine",
        "picture": "none.jpg",
        "picture_dir": "",
        "soundfile": "",
        "user_id": "1",
        "created": "2015-04-08 16:32:07",
        "modified": "0000-00-00 00:00:00"
    },
    {
        "id": "2",
        "word": "computer",
        "word_syllables": "com-pute-r",
        "picture": "computer.jpg",
        "picture_dir": "",
        "soundfile": "",
        "user_id": "0",
        "created": "2015-04-08 16:32:07",
        "modified": "0000-00-00 00:00:00"
    }
]