我试图在控制器类中伪造一些问答对，并通过使用playframework将它们发送到视图类中。
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
...
我在Application.java类中有这些。目前它们是硬编码的，以后我想使用数据库。
然后我有一个index.scala.html(视图类)，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——这不起作用！
但是如何将它们从java类发送到scala类呢？
到目前为止，我已经尝试使用谷歌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)
}
我知道我在错误地迭代答案，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
...
所以我展示了每一个问题的每一个答案。这源于我不知道如何将答案与相应的问题联系起来的问题！我在问答中有ID，但我不知道如何将这些ID(连同q/a文本！)放入视图类，以及如何迭代这些ID。
也许我可以使用另一种数据结构来简化我的方法？
[EDIT1]========================================[EDIT1]
我现在已经改变了我的方法，使用了一个包含两个类(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(控制器类)中，我使用了一个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，我如何迭代answerText并在视图类中显示它们呢？我不知道如何进入这个列表。
只需使用内部循环来迭代答案(因为值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>
}
}