java - 如何将问题/答案对转移到 playframework 中的 View 类中？

Question

我试图在我的 Controller 类中伪造一些问题/答案对，并通过使用 playframework 将它们发送到 View 类中。

我的问题/答案结构如下:

- Question 1
-- Answer 1.1
-- Answer 1.2

- Question 2
-- Answer 2.1

- Question 3
-- Answer 3.1
-- Answer 3.2
...

我的 Application.java 类中有这些。目前它们是硬编码的，稍后我想使用数据库。

然后我有一个index.scala.html( View 类)，在那里我迭代问题和答案并像在我的结构中一样显示它们 - 这是行不通的!

但是如何将它们从 java 类发送到 scala 类呢？

到目前为止，我已经尝试使用 Google Guava Multimap:

// Needed, as the view-class gets a List[String]
static List<String> questionList = new ArrayList<String>();
static List<String> answerList = new ArrayList<String>();

// Create the Multimap, one for questions, one for answers
    Multimap<String, String> questionMap = ArrayListMultimap.create();
    Multimap<String, String> answerMap = ArrayListMultimap.create();

// Question 1, in the format Questiontext (used as key here) / ID, votescore, Userid
    questionMap.put("What happens if I use a break here?", "e77dccbc-fd8d-4641-b9ca-17528e5d56b2");
    questionMap.put("What happens if I use a break here?", "150");
    questionMap.put("What happens if I use a break here?", "345");

    // Answer 1.1 in the format: Answertext / ID / Question-ID (Answer needs to be linked to a question) / votescore / Userid
    answerMap.put("The loop will just fall through!", "b8756ff5-ff8a-4a17-9517-811b91639fdf");
    answerMap.put("The loop will just fall through!", "e77dccbc-fd8d-4641-b9ca-17528e5d56b2");
    answerMap.put("The loop will just fall through!", "46");
    answerMap.put("The loop will just fall through!", "567");

// The Lists get the keySets (contains the questiontext / answertext)
    questionList.addAll(questionMap.keySet());
    answerList.addAll(answerMap.keySet());

// returns the 2 lists to the view-class
public static Result index() {
    return ok(index.render(questionList, answerList));
}

index.scala.html:

// first line, gets the q/a lists as parameters
@(questions: List[String], answers: List[String])

// iterate over the question-list and show the questiontext (works)

@for(index <- 0 until questions.size){
    @questions(index)

// iterate over the answers and show them as well, I know I am iterating wrong somehow here!
@for(index <- 0 until answers.size){
    @answers(index)
}

我知道我错误地迭代了答案，所以现在显示的结构是:

- Question 1
-- Answer 1.1
-- Answer 1.2
-- Answer 2.1
-- Answer 3.1
-- Answer 3.2

- Question 2
-- Answer 1.1
-- Answer 1.2
-- Answer 2.1
-- Answer 3.1
-- Answer 3.2

- Question 3
-- Answer 1.1
-- Answer 1.2
-- Answer 2.1
-- Answer 3.1
-- Answer 3.2
...

所以我会显示每个问题的每个答案。这源于我不知道如何将答案链接到相应问题的问题!我的问题和答案中有 ID，但我不知道如何将它们(与 q/a 文本一起!)放入 View 类中以及如何迭代 ID。

也许我可以使用另一种数据结构来使我的方法更容易？

[编辑1]============================================ ===========[编辑1]

我现在改变了我的方法并使用带有 2 个类(Question.java 和 Answer.java)的普通 Map:

Question.java(Answer.java 类似):

public class Question {

public String ID;
public String questionText;
public Integer voteScore;
public String userID;

public Question(String inputID, String inputQuestionText, Integer inputVoteScore, String inputUserID){
    this.ID = inputID;
    this.questionText = inputQuestionText;
    this.voteScore = inputVoteScore;
    this.userID = inputUserID;
}
}

在我的 Application.java ( Controller 类)中，我使用 Map 并有一些假问题/答案:

static Map<Question, List<Answer>> myMap = new HashMap<Question, List<Answer>>();

Question question1 = new Question("xyz", "Do Androids dream?", 127, "Marcus");
Answer answer11 = new Answer("zab", "xyz", "Only of electric sheep!", 70, "Tibor");
Answer answer12 = new Answer("qwert", "xyz", "No, they dont!", 10, "Sarah");

Question question2 = new Question("fgh", "Why is the sky blue?", 76, "Frank");
Answer answer21 = new Answer("xcv", "fgh", "Frequency filtered sunlight!", 45, "Oliver");
Answer answer22 = new Answer("tzu", "fgh", "Light reflects from the blue sea water!", 3, "Tom");

List<Answer> answerList1 = new ArrayList<Answer>();
answerList1.add(answer11);
answerList1.add(answer12);

List<Answer> answerList2 = new ArrayList<Answer>();
answerList2.add(answer21);
answerList2.add(answer22);

myMap.put(question1, answerList1);
myMap.put(question2, answerList2);

return ok(views.html.index.render(myMap));

在我的index.scala.html中:

@import model.Question
@import model.Answer

@(myMap: Map[Question, List[Answer]])

@for((key, value) <- myMap){
  @key.questionText - @value <br>
}

现在的输出是:

Why is the sky blue? - 
[ID = xcv questionID = fgh answerText = Frequency filtered sunlight! voteScore = 45 userID = Oliver, ID = tzu questionID = fgh answerText = Light reflects from the blue sea water! voteScore = 3 userID = Tom]

Do Androids dream? - 
[ID = zab questionID = xyz answerText = Only of electric sheep! voteScore = 70 userID = Tibor, ID = qwert questionID = xyz answerText = No, they dont! voteScore = 10 userID = Sarah] 

那么如何迭代answerTexts 并将它们显示在我的 View 类中？我不知道如何访问该列表。

Answer 1

只需使用内部循环来迭代答案(因为 value 变量将保存循环迭代问题的答案):

index.scala.html

@import model.Question
@import model.Answer

@(myMap: Map[Question, List[Answer]])

@for((key, value) <- myMap){
  @key.questionText<br>
  @for(ans <- value){
     <p>Possible answer: @ans.answerText</p>
  }
}