为什么我得到的地图类型不匹配作为路由参数？

Question

我正在使用 playframework 2.3.8 并且有一个视图-class。里面有一个按钮：

<button class="btn btn-default" type="button" onclick="@routes.Application.sendMap(myMap)" method="POST">Send</button>

我想在我的控制器中的地图上附加一个问题/答案对 class (Application.java):

public static Result sendMap(Map<Question, List<Answer>> sendMap){
    Question question4 = new Question("ertw", "SendMap Question?", 34, "Tim");
    Answer answer41 = new Answer("werw", "ertw", "SendMap Answer 1!", 12, "Oliver");
    Answer answer42 = new Answer("tzsdfu", "ertw", "SendMap Answer 2!", 1, "Marcus");

    List<Answer> answerList4 = new ArrayList<Answer>();
    answerList4.add(answer41);
    answerList4.add(answer42);

    sendMap.put(question4, answerList4);
    return ok(views.html.frageAntwort.render(sendMap));
}

在我的 routes.conf 中，我已经将路由添加到控制器 class 并使用 Map 作为参数：

POST    /QuestionMap                    controllers.Application.sendMap(Map)

但现在我收到错误：

type mismatch; found : String required: java.util.Map[model.Question,java.util.List[model.Answer]]

为什么地图会转换成字符串？

Answer 1

默认参数类型为字符串："For parameters of type String, the parameter type is optional." Documentation Play. You can also take a look there: How to create Map - post on Stack Overflow。您应该创建正确的模板，然后通过配置文件中方法中的参数传递它

Answer 2

我已经搞定了几乎完全现在正在工作......虽然我不完全明白如何：

视图中的我的按钮-class，现在没有任何参数

<a href="@routes.Application.sendMap()"><button class="btn btn-default" type="button">Absenden</button>

我的控制器-class 现在可以正确地将另一个 fake question/answer 对放入地图中，然后 returns 它与更改后的地图index.scala.html:

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

最重要的部分发生在 routes.conf:

GET     /                           controllers.Application.index()
GET     /Fragenliste                controllers.Application.sendMap()
GET     /FrageStellen               controllers.Application.askQuestion()
GET     /Einstellungen              controllers.Application.showSettings()
GET     /Quiz                       controllers.Application.startQuiz()

sendMap() 现在没有参数并指向另一个名为 /Fragenliste 的站点。还有我不完全理解的部分 - 如果我使用

GET     /                           controllers.Application.sendMap()

它指向Application.java中的index()-方法。在那里我有另一个方法叫做 initialize():

public static Result index() {
    initialize();
    (...)
}

public static void initialize() {
    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");

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

    myMap.clear();
    myMap.put(question1, answerList1);
}

在我清除了旧地图的潜在剩余部分之后，地图就构建完成了。所以我的路线指向索引，现在没有添加新问题！为什么我不能同时指向索引并让它继续工作？

基本上：

mysite.com/ = index ... user presses button for new question, gets transfered to
mysite.com/enterQuestion ... user enters question and hits "submit", gets transfered to
mysite.com/ = index

我目前的解决方案是：

mysite.com/ = index ... user presses button for new question, gets transfered to
mysite.com/enterQuestion ... user enters question and hits "submit", gets transfered to
mysite.com/ANOTHER_SITE != index, but looks and works exactly like the index!

有办法吗？如果是的话，我的问题就彻底解决了。

为什么我得到的地图类型不匹配作为路由参数？

Why do I get a type mismatch for a map as a routing parameter?

java

dictionary

playframework

scala-template