发表新帖
发表新帖

How to create a custom 404 page handler with Play 2.0?

后端 未结
关注
7 2087
故里飘歌
故里飘歌 2021-01-03 19:22

What’s the preferred way to handle 404 errors with Play 2.0 and show a nice templated view?

相关标签:
7条回答
  • 南方客
    2021-01-03 19:41

    Please note that Play development team are making lots of efforts to move away from global state in Play, and hence GlobalSettings and the application Global object have been deprecated since version 2.4.

    HttpErrorHandler.onClientError should be used instead of GlobalSettings.onHandlerNotFound. Basically create a class that inherits from HttpErrorHandler, and provide an implementation for onClientError method.

    In order to find out type of error (404 in your case) you need to read status code, which is passed as a one of the method arguments e.g.

    if(statusCode == play.mvc.Http.Status.NOT_FOUND) {
    // your code to handle 'page not found' situation 
    // e.g. return custom implementation of 404 page
}

    In order to let Play know what handler to use, you can place your error handler in the root package or configure it in application.conf using play.http.errorHandler configuration key e.g.

    play.http.errorHandler = "my.library.MyErrorHandler"

    You can find more details on handling errors here: for Scala or Java.

    0 讨论(0)
  • 無奈伤痛
    2021-01-03 19:52

    This works in 2.2.1. In Global.java:

    public Promise<SimpleResult> onHandlerNotFound(RequestHeader request) {
    return Promise.<SimpleResult>pure(notFound(
        views.html.throw404.render()
    ));
}

    Ensure that you have a view called /views/throw404.scala.html

    0 讨论(0)
  • 终归单人心
    2021-01-03 19:54

    For Java, if you want to just redirect to main page, I solved it by this.

    @Override
public Promise<Result> onHandlerNotFound(RequestHeader request) {
    return Promise.pure(redirect("/"));
}
    0 讨论(0)
  • 旧巷少年郎
    2021-01-03 19:56

    Please note that there are really two different problems to solve:

    1. Showing a custom 404 page when there is "no handler found", e.g. when the user goes to an invalid URL, and

    2. Showing a custom 404 (NotFound) page as a valid outcome of an existing handler.

    I think the OP was referring to #2 but answers referred to #1.

    "No Handler Found" Scenario

    In the first scenario, for "no handler found" (i.e. invalid URL), the other answers have it right but to be more detailed, per the Play 2.1 documentation as:

    Step 1: add a custom Global object:

    import play.api._
import play.api.mvc._
import play.api.mvc.Results._

object Global extends GlobalSettings {

  override def onHandlerNotFound(request: RequestHeader): Result = {
    NotFound(
      views.html.notFoundPage(request.path)
    )
  }   
}

    Step 2: add the template. Here's mine:

    @(path: String)

<html>
<body>
<h1>Uh-oh. That wasn't found.</h1>
<p>@path</p>
</body>
</html>

    Step 3: tweak your conf/application.conf to refer to your new "Global". I put it in the controllers package but it doesn't have to be:

    ...
application.global=controllers.Global

    Step 4: restart and go to an invalid URL.

    "Real Handler can't find object" Scenario

    In the second scenario an existing handler wants to show a custom 404. For example, the user asked for object "1234" but no such object exists. The good news is that doing this is deceptively easy:

    Instead of Ok(), surround your response with NotFound()

    For example:

    object FruitController extends Controller {

  def showFruit(uuidString: String) = Action {
    Fruits.find(uuidString) match {
      case Some(fruit) => Ok(views.html.showFruit(fruit))

      // NOTE THE USE OF "NotFound" BELOW!
      case None => NotFound(views.html.noSuchFruit(s"No such fruit: $uuidString"))
    }
  }
}

    What I like about this is the clean separation of the status code (200 vs 404) from the HTML returned (showFruit vs noSuchFruit).

    HTH Andrew

    0 讨论(0)
  • 挽巷
    2021-01-03 20:00

    You can override the onHandlerNotFound method on your Global object, e.g.:

    object Global extends GlobalSettings {
  override def onHandlerNotFound(request: RequestHeader): Result = {
    NotFound(views.html.notFound(request))
  }
}
    0 讨论(0)
  • 一生所求
    2021-01-03 20:04

    If you want to do the same using Java instead of Scala you can do it in this way (this works for play framework 2.0.3):

    Global.java:

    import play.GlobalSettings;
import play.mvc.Result;
import play.mvc.Results;
import play.mvc.Http.RequestHeader;


public class Global extends GlobalSettings {

    @Override
    public Result onHandlerNotFound(RequestHeader request) {
        return Results.notFound(views.html.error404.render());
    }
}

    Asumming that your 404 error template is views.html.error404 (i.e. views/error404.scala.html).

    0 讨论(0)
 看不清?
提交回复
热议问题