我已经查看了所有其他与此有关的stackoverflow主题，并且它们在被调用的JSON中几乎总是存在相同的缺陷，即JSON仅包含一个对象，而不包含数组。我已确定要解决此问题，在下面您可以看到在Postman中执行查询后返回的JSON。
我已经用尽了所有的解决方案，因为每个在线解决方案都涉及将JSON转换为数组，就像我已经做过的那样。我在网上找到了有关如何使用改型（Call<List<Object>>来调用列表的教程，该教程使用几乎相同的代码进行挖掘，并且JSON的格式相同，所以我认为我的JSON是正确的
首先，返回JSON：
[
{
"is_active": 1,
"match_date": "Wed, 09 Oct 2019 13:53:27 GMT",
"match_id": 2,
"match_winner_user_id": null,
"rnd1_cat1": "test category1",
"rnd1_cat1_q1": {
"category_id": 1,
"correct_answer": {
"answer_id": 1,
"answer_text": "test answer1",
"is_active": 1
},
"incorrect_answer1": {
"answer_id": 2,
"answer_text": "test answer2",
"is_active": 1
},
"incorrect_answer2": {
"answer_id": 3,
"answer_text": "test answer3",
"is_active": 1
},
"incorrect_answer3": {
"answer_id": 4,
"answer_text": "test answer4",
"is_active": 1
},
"is_active": 1,
"question_id": 1,
"question_text": "test question text1",
"user1_answer": 1,
"user2_answer": 2
},
"rnd1_cat1_q1_user1_answer": 1,
"rnd1_cat1_q1_user2_answer": 2,
"rnd1_cat1_q2": {
"category_id": 1,
"correct_answer": {
"answer_id": 4,
"answer_text": "test answer4",
"is_active": 1
},
"incorrect_answer1": {
"answer_id": 3,
"answer_text": "test answer3",
"is_active": 1
},
"incorrect_answer2": {
"answer_id": 2,
"answer_text": "test answer2",
"is_active": 1
},
"incorrect_answer3": {
"answer_id": 1,
"answer_text": "test answer1",
"is_active": 1
},
"is_active": 1,
"question_id": 2,
"question_text": "test question text2",
"user1_answer": 2,
"user2_answer": 2
},
"rnd1_cat1_q2_user1_answer": 2,
"rnd1_cat1_q2_user2_answer": 2,
"rnd1_cat1_q3": {
"category_id": 1,
"correct_answer": {
"answer_id": 3,
"answer_text": "test answer3",
"is_active": 1
},
"incorrect_answer1": {
"answer_id": 4,
"answer_text": "test answer4",
"is_active": 1
},
"incorrect_answer2": {
"answer_id": 2,
"answer_text": "test answer2",
"is_active": 1
},
"incorrect_answer3": {
"answer_id": 1,
"answer_text": "test answer1",
"is_active": 1
},
"is_active": 1,
"question_id": 3,
"question_text": "test question text3",
"user1_answer": 5,
"user2_answer": 4
},
"rnd1_cat1_q3_user1_answer": 5,
"rnd1_cat1_q3_user2_answer": 4,
"rnd1_cat2": "test category2",
"rnd1_cat2_q1": {
"category_id": 2,
"correct_answer": {
"answer_id": 6,
"answer_text": "test answer6",
"is_active": 1
},
"incorrect_answer1": {
"answer_id": 4,
"answer_text": "test answer4",
"is_active": 1
},
"incorrect_answer2": {
"answer_id": 2,
"answer_text": "test answer2",
"is_active": 1
},
"incorrect_answer3": {
"answer_id": 1,
"answer_text": "test answer1",
"is_active": 1
},
"is_active": 1,
"question_id": 4,
"question_text": "test question text4",
"user1_answer": null,
"user2_answer": null
},
"rnd1_cat2_q1_user1_answer": null,
"rnd1_cat2_q1_user2_answer": null,
"rnd1_cat2_q2": {
"category_id": 3,
"correct_answer": {
"answer_id": 6,
"answer_text": "test answer6",
"is_active": 1
},
"incorrect_answer1": {
"answer_id": 4,
"answer_text": "test answer4",
"is_active": 1
},
"incorrect_answer2": {
"answer_id": 2,
"answer_text": "test answer2",
"is_active": 1
},
"incorrect_answer3": {
"answer_id": 1,
"answer_text": "test answer1",
"is_active": 1
},
"is_active": 1,
"question_id": 5,
"question_text": "test question text5",
"user1_answer": null,
"user2_answer": null
},
"rnd1_cat2_q2_user1_answer": null,
"rnd1_cat2_q2_user2_answer": null,
"rnd1_cat2_q3": {
"category_id": 1,
"correct_answer": {
"answer_id": 2,
"answer_text": "test answer2",
"is_active": 1
},
"incorrect_answer1": {
"answer_id": 5,
"answer_text": "test answer5",
"is_active": 1
},
"incorrect_answer2": {
"answer_id": 4,
"answer_text": "test answer4",
"is_active": 1
},
"incorrect_answer3": {
"answer_id": 1,
"answer_text": "test answer1",
"is_active": 1
},
"is_active": 1,
"question_id": 6,
"question_text": "test question text6",
"user1_answer": null,
"user2_answer": null
},
"rnd1_cat2_q3_user1_answer": null,
"rnd1_cat2_q3_user2_answer": null,
"rnd2_cat1": null,
"rnd2_cat1_q1": null,
"rnd2_cat1_q1_user1_answer": null,
"rnd2_cat1_q1_user2_answer": null,
"rnd2_cat1_q2": null,
"rnd2_cat1_q2_user1_answer": null,
"rnd2_cat1_q2_user2_answer": null,
"rnd2_cat1_q3": null,
"rnd2_cat1_q3_user1_answer": null,
"rnd2_cat1_q3_user2_answer": null,
"rnd2_cat2": null,
"rnd2_cat2_q1": null,
"rnd2_cat2_q1_user1_answer": null,
"rnd2_cat2_q1_user2_answer": null,
"rnd2_cat2_q2": null,
"rnd2_cat2_q2_user1_answer": null,
"rnd2_cat2_q2_user2_answer": null,
"rnd2_cat2_q3": null,
"rnd2_cat2_q3_user1_answer": null,
"rnd2_cat2_q3_user2_answer": null,
"user1_id": 36,
"user2_id": 21
},
{
"is_active": 1,
"match_date": "Wed, 09 Oct 2019 13:53:27 GMT",
"match_id": 2,
"match_winner_user_id": null,
"rnd1_cat1": "test category1",
"rnd1_cat1_q1": {
"category_id": 1,
"correct_answer": {
"answer_id": 1,
"answer_text": "test answer1",
"is_active": 1
},
"incorrect_answer1": {
"answer_id": 2,
"answer_text": "test answer2",
"is_active": 1
},
"incorrect_answer2": {
"answer_id": 3,
"answer_text": "test answer3",
"is_active": 1
},
"incorrect_answer3": {
"answer_id": 4,
"answer_text": "test answer4",
"is_active": 1
},
"is_active": 1,
"question_id": 1,
"question_text": "test question text1",
"user1_answer": 1,
"user2_answer": 2
},
"rnd1_cat1_q1_user1_answer": 1,
"rnd1_cat1_q1_user2_answer": 2,
"rnd1_cat1_q2": {
"category_id": 1,
"correct_answer": {
"answer_id": 4,
"answer_text": "test answer4",
"is_active": 1
},
"incorrect_answer1": {
"answer_id": 3,
"answer_text": "test answer3",
"is_active": 1
},
"incorrect_answer2": {
"answer_id": 2,
"answer_text": "test answer2",
"is_active": 1
},
"incorrect_answer3": {
"answer_id": 1,
"answer_text": "test answer1",
"is_active": 1
},
"is_active": 1,
"question_id": 2,
"question_text": "test question text2",
"user1_answer": 2,
"user2_answer": 2
},
"rnd1_cat1_q2_user1_answer": 2,
"rnd1_cat1_q2_user2_answer": 2,
"rnd1_cat1_q3": {
"category_id": 1,
"correct_answer": {
"answer_id": 3,
"answer_text": "test answer3",
"is_active": 1
},
"incorrect_answer1": {
"answer_id": 4,
"answer_text": "test answer4",
"is_active": 1
},
"incorrect_answer2": {
"answer_id": 2,
"answer_text": "test answer2",
"is_active": 1
},
"incorrect_answer3": {
"answer_id": 1,
"answer_text": "test answer1",
"is_active": 1
},
"is_active": 1,
"question_id": 3,
"question_text": "test question text3",
"user1_answer": 5,
"user2_answer": 4
},
"rnd1_cat1_q3_user1_answer": 5,
"rnd1_cat1_q3_user2_answer": 4,
"rnd1_cat2": "test category2",
"rnd1_cat2_q1": {
"category_id": 2,
"correct_answer": {
"answer_id": 6,
"answer_text": "test answer6",
"is_active": 1
},
"incorrect_answer1": {
"answer_id": 4,
"answer_text": "test answer4",
"is_active": 1
},
"incorrect_answer2": {
"answer_id": 2,
"answer_text": "test answer2",
"is_active": 1
},
"incorrect_answer3": {
"answer_id": 1,
"answer_text": "test answer1",
"is_active": 1
},
"is_active": 1,
"question_id": 4,
"question_text": "test question text4",
"user1_answer": null,
"user2_answer": null
},
"rnd1_cat2_q1_user1_answer": null,
"rnd1_cat2_q1_user2_answer": null,
"rnd1_cat2_q2": {
"category_id": 3,
"correct_answer": {
"answer_id": 6,
"answer_text": "test answer6",
"is_active": 1
},
"incorrect_answer1": {
"answer_id": 4,
"answer_text": "test answer4",
"is_active": 1
},
"incorrect_answer2": {
"answer_id": 2,
"answer_text": "test answer2",
"is_active": 1
},
"incorrect_answer3": {
"answer_id": 1,
"answer_text": "test answer1",
"is_active": 1
},
"is_active": 1,
"question_id": 5,
"question_text": "test question text5",
"user1_answer": null,
"user2_answer": null
},
"rnd1_cat2_q2_user1_answer": null,
"rnd1_cat2_q2_user2_answer": null,
"rnd1_cat2_q3": {
"category_id": 1,
"correct_answer": {
"answer_id": 2,
"answer_text": "test answer2",
"is_active": 1
},
"incorrect_answer1": {
"answer_id": 5,
"answer_text": "test answer5",
"is_active": 1
},
"incorrect_answer2": {
"answer_id": 4,
"answer_text": "test answer4",
"is_active": 1
},
"incorrect_answer3": {
"answer_id": 1,
"answer_text": "test answer1",
"is_active": 1
},
"is_active": 1,
"question_id": 6,
"question_text": "test question text6",
"user1_answer": null,
"user2_answer": null
},
"rnd1_cat2_q3_user1_answer": null,
"rnd1_cat2_q3_user2_answer": null,
"rnd2_cat1": null,
"rnd2_cat1_q1": null,
"rnd2_cat1_q1_user1_answer": null,
"rnd2_cat1_q1_user2_answer": null,
"rnd2_cat1_q2": null,
"rnd2_cat1_q2_user1_answer": null,
"rnd2_cat1_q2_user2_answer": null,
"rnd2_cat1_q3": null,
"rnd2_cat1_q3_user1_answer": null,
"rnd2_cat1_q3_user2_answer": null,
"rnd2_cat2": null,
"rnd2_cat2_q1": null,
"rnd2_cat2_q1_user1_answer": null,
"rnd2_cat2_q1_user2_answer": null,
"rnd2_cat2_q2": null,
"rnd2_cat2_q2_user1_answer": null,
"rnd2_cat2_q2_user2_answer": null,
"rnd2_cat2_q3": null,
"rnd2_cat2_q3_user1_answer": null,
"rnd2_cat2_q3_user2_answer": null,
"user1_id": 36,
"user2_id": 21
}
]
和接口类：
@POST("/api/v1/match/getMatches")
Call<List<Match>> getMatches(@Header("Authorization") String authorization);
Match类，仅用于注释对象和自动生成的吸气剂：
import com.google.gson.annotations.SerializedName;
public class Match {
@SerializedName("match_id")
private int matchId;
@SerializedName("user1_id")
private int user1Id;
@SerializedName("user2_id")
private int user2Id;
// Categories
@SerializedName("rnd1_cat1")
private String rnd1_cat1;
@SerializedName("rnd1_cat2")
private String rnd1_cat2;
@SerializedName("rnd2_cat1")
private String rnd2_cat1;
@SerializedName("rnd2_cat2")
private String rnd2_cat2;
//Questions, which contain answers objects within them
@SerializedName("rnd1_cat1_q1")
private Question rnd1_cat1_q1;
@SerializedName("rnd1_cat1_q2")
private Question rnd1_cat1_q2;
@SerializedName("rnd1_cat1_q3")
private Question rnd1_cat1_q3;
//Cat2
@SerializedName("rnd1_cat2_q1")
private Question rnd1_cat2_q1;
@SerializedName("rnd1_cat2_q2")
private Question rnd1_cat2_q2;
@SerializedName("rnd1_cat2_q3")
private Question rnd1_cat2_q3;
//Round 2
@SerializedName("rnd2_cat1_q1")
private Question rnd2_cat1_q1;
@SerializedName("rnd2_cat1_q2")
private Question rnd2_cat1_q2;
@SerializedName("rnd2_cat1_q3")
private Question rnd2_cat1_q3;
//Cat2
@SerializedName("rnd2_cat2_q1")
private Question rnd2_cat2_q1;
@SerializedName("rnd2_cat2_q2")
private Question rnd2_cat2_q2;
@SerializedName("rnd2_cat2_q3")
private Question rnd2_cat2_q3;
public int getMatchId() {
return matchId;
}
public int getUser1Id() {
return user1Id;
}
public int getUser2Id() {
return user2Id;
}
public String getRnd1_cat1() {
return rnd1_cat1;
}
public String getRnd1_cat2() {
return rnd1_cat2;
}
public String getRnd2_cat1() {
return rnd2_cat1;
}
public String getRnd2_cat2() {
return rnd2_cat2;
}
public Question getRnd1_cat1_q1() {
return rnd1_cat1_q1;
}
public Question getRnd1_cat1_q2() {
return rnd1_cat1_q2;
}
public Question getRnd1_cat1_q3() {
return rnd1_cat1_q3;
}
public Question getRnd1_cat2_q1() {
return rnd1_cat2_q1;
}
public Question getRnd1_cat2_q2() {
return rnd1_cat2_q2;
}
public Question getRnd1_cat2_q3() {
return rnd1_cat2_q3;
}
public Question getRnd2_cat1_q1() {
return rnd2_cat1_q1;
}
public Question getRnd2_cat1_q2() {
return rnd2_cat1_q2;
}
public Question getRnd2_cat1_q3() {
return rnd2_cat1_q3;
}
public Question getRnd2_cat2_q1() {
return rnd2_cat2_q1;
}
public Question getRnd2_cat2_q2() {
return rnd2_cat2_q2;
}
public Question getRnd2_cat2_q3() {
return rnd2_cat2_q3;
}
}
问题类：
import com.google.gson.annotations.SerializedName;
public class Question {
@SerializedName("question_id")
private int questionId;
@SerializedName("category_name")
private String category;
@SerializedName("question_text")
private String questionText;
@SerializedName("correct_answer")
private Answer correctAnswer;
@SerializedName("incorrect_answer1")
private Answer incorrectAnswer1;
@SerializedName("incorrect_answer2")
private Answer incorrectAnswer2;
@SerializedName("incorrect_answer3")
private Answer incorrectAnswer3;
public int getQuestionId() {
return questionId;
}
public String getCategory() {
return category;
}
public String getQuestionText() {
return questionText;
}
public Answer getCorrectAnswer() {
return correctAnswer;
}
public Answer getIncorrectAnswer1() {
return incorrectAnswer1;
}
public Answer getIncorrectAnswer2() {
return incorrectAnswer2;
}
public Answer getIncorrectAnswer3() {
return incorrectAnswer3;
}
}
和Answer类：
import com.google.gson.annotations.SerializedName;
public class Answer {
@SerializedName("answer_id")
private int answerId;
@SerializedName("answer_text")
private String answerText;
public int getAnswerId() {
return answerId;
}
public String getAnswerText() {
return answerText;
}
}
最后是电话：
Call<List<Match>> call = backendApi.getMatches(auth_token);
call.enqueue(new Callback<List<Match>>() {
@Override
public void onResponse(Call<List<Match>> call, Response<List<Match>> response) {
if(!response.isSuccessful()){
Log.e("login activity", "2");
return;
}
List<Match> matchList = response.body();
Log.i("match list", matchList.size()+"");
}
@Override
public void onFailure(Call<List<Match>> call, Throwable t) {
Log.e("retrofit", t.getMessage());
}
});
由于某种原因，我得到了一个错误：预期是BEGIN_ARRAY，但在第1行第2列路径处是BEGIN_OBJECT，尽管据我所知一切正常。
非常感谢您的帮助！
编辑：我似乎注意到Postman和Retrofit认为Header中的Content-Lengths不同。邮递员会看到一个真正的值，对于json中的一次匹配，它的值为5000+，并且Retrofit无论如何都返回64的Content-Length。奇怪的。