播放框架路由和scala predef值

Question

我在play framework 2.2上开发应用程序我有一个像这样的路由文件:

GET  /posting/          controllers.posting.BlogController.allPosts()
GET  /posting/:number   controllers.posting.BlogController.allPosts(number: Int)

和BlogContriller:

object BlogController extends Controller {

  def allPosts(pageNumber:Int = 1, postsPerPage:Int = 10) = Action{
    val posts = Post.getLastNPosts(postsPerPage, postsPerPage*(pageNumber-1))
    val htmlPosts = new Html(new StringBuilder());

    for (post <- posts){
      val htmlPost = views.html.posting.post(post.getName, post.getText, post.getDate.toString)
      htmlPosts += htmlPost;
    }

    Ok(views.html.posting.index(htmlPosts))
  }
}

当我试图加入时,我给出了一个错误:

Error:(14, -1) Play 2 Compiler:  C:\...\conf\routes:14: Compilation error[Using different overloaded methods is not allowed. If you are using a single method in combination with default parameters, make sure you declare them all explicitly.]
GET  /posting/:number   controllers.posting.BlogController.allPosts(number: Int)

我无法理解如何解决这个问题.谁能帮我？

Answer 1

您必须使用带默认值的参数:

GET  /posting/          controllers.posting.BlogController.allPosts(number: Int = 1)
GET  /posting/:number   controllers.posting.BlogController.allPosts(number: Int)

您可能不会使用重载方法allPosts(Int)和allPosts.由于您allPosts使用默认值声明了两个参数,因此Scala将此方法视为4种不同的方法.您只能使用其中一个.