I would like to disable the color escape codes logged from sbt/play. Is this possible? And if it is, is there a way to do it without making changes to the config - i.e. via a command line switch or system property.

How can colored terminal output be disabled for sbt/play?

How do you declare and initialize a variable to be used locally in a Play2 Scala template?

I have this:

    @var title : String = &quot;Home&quot;

declared at the top of the template, but it gives me this error:


    illegal start of simple expression &quot;&quot;&quot;),_display_(Seq[Any](/*3.2*/var)),format.raw/*3.5*/(&quot;&quot;&quot; title : String = &quot;Home&quot;


Declare variable in a Play2 scala template

I am really torn between two different stacks with which to build a large application. One the one hand there is this option:

- Node.js
    - express
    - coffee script
    - coffeekup
    - mongoose/mongodb
    or
    - presistencejs/mysql

&lt;br/&gt;

- Play Framework w/ Scala
  - Anorm w/ mysql
  - or mongodb

The node.js path is appealing to me because i can write all of the server side code, views and client side code in coffeescript, which i already know. If i go down this road i am still not 100% sure which db path i would take. mongoose makes storing data quick and easy, but the lack of true relationships might be more difficult to work with given the data model i have in mind (very SQLish).

The Play Framework path is also appealing because i know the framework well when using Java, but i don&#39;t know much about Scala, so there would be a hit to productivity as i work through learning that language. The Anorm database access layer is appealing because i can write the SQL by hand which i would prefer, and have the results mapped to objects automatically, which saves a lot of effort.

I keep leaning towards node.js, but i&#39;m not sold on the best db access layer to use. Anyone have any experience with any of this and can share some insight?

NodeJS vs Play Framework for large project

With the recent release of Play Framework 2.0, I would like to know if anyone could summarize ,from a high level standpoint, the major differences between Play Framework 1 &amp; 2.

I already compiled a few (play 1.0 -&gt; play 2.0):

* Template engine: Groovy Pages -&gt; Scala Templates
* Persistance: Hibernate -&gt; Ebean
* Language support: Java -&gt; Scala, Java
* Dynamic compilation: byte code injection -&gt; dynamic compilation via SBT
* Build system: n/a -&gt; SBT
* Extensibility: Modules, Plugins -&gt; SubProjects, Plugins, SBT plugin

What else ? Akka?

What are the major differences between Play Framework 1.0 and 2.0?

I want to be able to use `-Xfatal-warnings` and `-Ywarn-unused-import`, the problem is that the compiler is triggering an error on the file which contains the play routes for my application:

    [error] /path/to/app/conf/routes: Unused import
    [error] /path/to/app/conf/routes: Unused import
    [error] /path/to/app/conf/routes:1: Unused import
    [error] GET        /document/:id        my.app.controllers.MyController.getById(id: Int)

same goes for other routes.

Is it possible maybe to tell scalac to ignore a file?

Scala version is `2.11.8`.

-Ywarn-unused-import triggering on play routes file

The [Play Framework](http://www.playframework.org/) offers the following quick overview, but with the exception of the Groovy template engine (which you can get in Spring MVC if you want), Spring seems to offer all the same features and more...

 * __Fix the bug and hit reload!__ Edit your Java files, save, refresh your browser and see the results immediately! No need to compile, deploy or restart the server. _Spring does this, which can get annoying._

 * __Stateless model__ Play is a real &quot;Share nothing&quot; system. Ready for REST, it is easily scaled by running multiple instances of the same application on several servers. _Typical Spring applications have a stateless application tier; it&#39;s not purely RESTful unless you want to be, but Spring is &quot;ready for REST&quot;._

 * __Efficient template system__ A clean template system based on Groovy as an expression language. It provides template inheritence, includes and tags. _Spring uses Java, but Groovy is an option too._

 * __Resolve errors quickly__ When an error occurs, play shows you the source code and the exact line containing the problem. Even in templates. _Spring does this as well._

 * __All you need to create a cool web application__ Provides integration with Hibernate, OpenID, Memcached... And a plugin system. _Spring integrates with everything and more._

 * __Pure Java__ Code with Java, use any Java library and develop with your preferred IDE. Integrates nicely with eclipse or netbeans. _Spring is pure Java as well._

 * __Really fast__ Starts fast and runs fast! _Subjective, but Spring is pretty quick._

So what does the Play Framework actually do differently than Spring MVC?          
In a nutshell what can Spring do that Play framework cannot (and vice-versa)? 


Web Frameworks: How is Play different from Spring MVC?

I am building a Java web app, using the [Play! Framework][1].  I&#39;m hosting it on [playapps.net][2].  I have been puzzling for a while over the provided graphs of memory consumption.  Here is a sample:

![Heap Memory][3]

The graph comes from a period of consistent but nominal activity.  I did nothing to trigger the falloff in memory, so I presume this occurred because the garbage collector ran as it has almost reached its allowable memory consumption.

**My questions:**  

 - Is it fair for me to assume that my application does *not* have a memory leak, as it appears that all the memory is correctly reclaimed by the garbage collector when it does run?  
 - (from the title) Why is java waiting until the last possible second to run the garbage collector?  I am seeing significant performance degradation as the memory consumption grows to the top fourth of the graph.
 - If my assertions above are correct, then how can I go about fixing this issue?  The other posts I have read on SO seem opposed to calls to `System.gc()`, ranging from neutral (&quot;it&#39;s only a request to run GC, so the JVM may just ignore you&quot;) to outright opposed (&quot;code that relies on `System.gc()` is fundamentally broken&quot;).  Or am I off base here, and I should be looking for defects in my own code that is causing this behavior and intermittent performance loss?  

**UPDATE**  
I have opened a discussion on PlayApps.net pointing to this question and mentioning some of the points here; specifically @Affe&#39;s comment regarding the settings for a full GC being set very conservatively, and @G_H&#39;s comment about settings for the initial and max heap size. 

Here&#39;s a [link to the discussion][4], though you unfortunately need a playapps account to view it.

I will report the feedback here when I get it; thanks so much everyone for your answers, I&#39;ve already learned a great deal from them!

**Resolution**  
Playapps support, which is still great, didn&#39;t have many suggestions for me, their only thought being that if I was using the cache extensively this may be keeping objects alive longer than need be, but that isn&#39;t the case.  I still learned a ton (woo hoo!), and I gave @Ryan Amos the green check as I took his suggestion of calling `System.gc()` every half day, which for now is working fine. 


  [1]: http://www.playframework.org/
  [2]: http://www.playapps.net/
  [3]: http://i.stack.imgur.com/2Y4GX.png
  [4]: http://help.playapps.net/discussions/questions/49-is-there-anything-non-standard-about-the-garbage-collection-used-by-the-jvm-on-playapps

Why does java wait so long to run the garbage collector?

I am calling a webservice like this:

    WS
      .url(url)
      .get
      .map { response =&gt; // error occurs on this line
        response.status match {
          case 200 =&gt; Right(response.json)
          case status =&gt; Left(s&quot;Problem accessing api, status &#39;$status&#39;&quot;)
      }
    }

The complete error: `Error: Cannot find an implicit ExecutionContext, either require one yourself or import ExecutionContext.Implicits.global`

Play Framework 2.1 - Cannot find an implicit ExecutionContext

How can I change the default port used by the play framework in development mode when issueing the &quot;run&quot; command on the play console.

This is for playframework 2.0 beta.

Using the http.port configuration parameter either on the command line or in the application.conf seems to have no effect:

    C:\dev\prototype\activiti-preso&gt;play run --http.port=8080
    [info] Loading project definition from C:\dev\prototype\activiti-preso\project
    [info] Set current project to activiti-preso (in build file:/C:/dev/prototype/activiti-preso/)
    
    
    Windows, really? Ok, disabling colors.
    
    --- (Running the application from SBT, auto-reloading is enabled) ---
    
    [error] org.jboss.netty.channel.ChannelException: Failed to bind to: 0.0.0.0/0.0.0.0:9000
    [error] Use &#39;last&#39; for the full log.



How do I change the default port (9000) that Play uses when I execute the &quot;run&quot; command?

Using AngularJS with Scala Play, I&#39;m getting this error.

&gt; Error: Argument &#39;MainCtrl&#39; is not a function, got undefined

I&#39;m trying to create a table consisting of the days of the week.

Please take a look at my code. I had checked the name of the Controller, but that seems correct. Note: Code used from this SO [answer][1]

**index.scala.html**

    @(message: String)
    
    @main(&quot;inTime&quot;) {
    
    &lt;!doctype html&gt;
    &lt;html lang=&quot;en&quot; ng-app&gt;
    	&lt;head&gt;
    		&lt;link rel=&quot;stylesheet&quot; media=&quot;screen&quot; href=&quot;@routes.Assets.at(&quot;stylesheets/main.css&quot;)&quot;&gt;
    	&lt;/head&gt;
    &lt;div ng-controller=&quot;MainCtrl&quot;&gt;
        &lt;table border=&quot;1&quot;&gt;
        &lt;tbody ng-repeat=&#39;(what,items) in data&#39;&gt;
          &lt;tr ng-repeat=&#39;item in items&#39;&gt;
            &lt;td ngm-if=&quot;$first&quot; rowspan=&quot;{{items.length}}&quot;&gt;{{what}}&lt;/td&gt;
            &lt;td&gt;{{item}}&lt;/td&gt;
          &lt;/tr&gt;
        &lt;/tbody&gt;
      &lt;/table&gt;
    &lt;/div&gt;
    &lt;/html&gt;	
    }

**MainCtrl.js** 

    (function() {
        angular.module(&#39;[myApp]&#39;, []).controller(&#39;MainCtrl&#39;, function($scope) {
            $scope.data = {
                Colors: [&quot;Monday&quot;, &quot;Tuesday&quot;, &quot;Wednesday&quot;, &quot;Thursday&quot;, &quot;Friday&quot;]
            }
        });
    }());


  [1]: https://stackoverflow.com/questions/11367769/creating-tables-with-angular-js

Error: Argument is not a function, got undefined

We are planning a project primarily serving content to mobile apps, but need to have a website.

My question is whether is makes sense to use Jersey or Restlet to develop REST APIs for our mobile apps, and then use Play! to serve the website. 

Or does it make more sense to just use Play! to do it all? If so, how to do REST with Play! framework? 

RESTful on Play! framework

There seems to be a current trend in java space to move away from deploying java web applications to a java servlet container (or application server) in the form of a war file (or ear file) and instead package the application as an executable jar with an embedded servlet/HTTP server like jetty. And I mean this more so in the way newer frameworks are influencing how new applications are developed and deployed rather than how applications are delivered to end users (because, for example, I get why Jenkins uses an embedded container, very easy to grab and go). Examples of frameworks adopting the executable jar option:
[Dropwizard][1], [Spring Boot][2], and [Play][3]  (well it doesn&#39;t run on a servlet container but the HTTP server is embedded).

My question is, coming from an environment where we have deployed our (up to this point mostly Struts2) applications to a single tomcat application server, what changes, best practices, or considerations need to be made if we plan on using an embedded container approach? Currently, we have about 10 homegrown applications running on a single tomcat server and for these smallish applications
the ability to share resources and be managed on one server is nice. Our applications are not intended to be distributed to end users to run within their environment.  However, moving forward if we decide to leverage a newer java framework, should this approach change?  Is the shift to executable jars spurred on by the increasing use of cloud deployments (e.g., Heroku)?

If you&#39;ve had experience managing multiple applications in the Play style of deployment versus traditional war file deployment on a single application server, please share your insight.


  [1]: https://dropwizard.github.io/dropwizard/
  [2]: http://projects.spring.io/spring-boot/
  [3]: http://www.playframework.com/

Advice deploying war files vs executable jar with embedded container

I&#39;m new to Play framework. I&#39;m trying to configure MySQL database as a datasource to be used with Play Ebeans. 

Could you some one please explain the steps that are needed to configure MySQL with Play 2.0 framework (like, downloading drivers, adding dependency etc).

Steps needed to use MySQL database with Play framework 2.0

Waaah, the Play! framework has so many static methods. Where I go to school, we were told _never ever_ to use any statics, yet Play! uses it like there&#39;s no tomorrow. Is that somehow okay? If so, why?

We (7 people and I) are planning to use the Play! framework for a project involving a web app. We decided to do it with Play! because it looks quite fun to do, all of us already know Java and the assignment is pretty hard so we wanted to focus on the actual assignment rather than also learning how to program in a different language.

We were always told, however, _NEVER EVER_ to use &#39;static&#39;s in any Java program we developed, but when I look at Play! ... Well... about half the methods are static. &amp;lt;/exaggeration&amp;gt;

I suppose, at the very least, we could use singleton objects (by using Scala, for example ^^) in order to program our project, but I&#39;m quite concerned at how many statics there actually are in framework itself.

So, should I be concerned about this? Did the way the Play! developers programmed it make it so that all these statics don&#39;t pose a problem?

(For example, [this thread][1] has a rant about why static members should be avoided at all costs.)


  [1]: http://www.allegro.cc/forums/thread/586752 &quot;this thread&quot;

Play! framework uses a &lt;lot&gt; of statics

This is my model:

    class User {...}
    class Book {
      User author;
      int number;
    }

Every book number starts at 1 per author and increments upwards. So we&#39;ll have Books 1,2,3 by John Grisham, Book 1..5 by George Martin, etc...

Is there a unique constraint I can place on `Book`, that would guarantee we don&#39;t have two books with the same number by the same author? Similar to `@Column(unique = true)`, but the constraint only applies on the composite of `Author X number`?



Creating a composite Unique constraints on multiple columns

Lets say I have an already functioning Play 2.0 framework based application in Scala that serves a URL such as:

http://localhost:9000/birthdays

which responds with a listing of all known birthdays

I now want to enhance this by adding the ability to restrict results with optional &quot;from&quot; (date) and &quot;to&quot; request params such as

http://localhost:9000/birthdays?from=20120131&amp;to=20120229

(dates here interpreted as yyyyMMdd)

My question is how to handle the request param binding and interpretation in Play 2.0 with Scala, especially given that both of these params should be optional. 

Should these parameters be somehow expressed in the &quot;routes&quot; specification? Alternatively, should the responding Controller method pick apart the params from the request object somehow? Is there another way to do this?





How to handle optional query parameters in Play framework

Is it possible to have a Play 2.3 app concat/optimize JS (using sbt-rjs) that&#39;s included in my app via WebJars?&lt;br&gt; To give a concrete example: I&#39;m trying to create a *core.js* module which contains all my 3rd party libraries concatenated and minified in a single file which can then be specified as a dependency for other AMD modules.&lt;br&gt; It would be great to include these libraries via WebJars instead of downloading the source &quot;manually&quot;.

Here&#39;s a snippet from my *build.sbt* file where I&#39;m specifying my webjar dependencies:

    // Webjars
    libraryDependencies ++= Seq(
      &quot;org.webjars&quot; % &quot;requirejs&quot; % &quot;2.1.15&quot;,
      &quot;org.webjars&quot; % &quot;underscorejs&quot; % &quot;1.7.0&quot;,
      &quot;org.webjars&quot; % &quot;jquery&quot; % &quot;1.11.1&quot;,
      &quot;org.webjars&quot; % &quot;bootstrap&quot; % &quot;3.3.1&quot; exclude(&quot;org.webjars&quot;, &quot;jquery&quot;),
      &quot;org.webjars&quot; % &quot;angularjs&quot; % &quot;1.3.4-1&quot; exclude(&quot;org.webjars&quot;, &quot;jquery&quot;)
    )

Here&#39;s my requireJS build config

    requirejs.config({
      baseUrl: &#39;/assets/javascripts&#39;,
      shim: {
        &#39;jsRoutes&#39;: {
          deps: [],
          exports: &#39;jsRoutes&#39;
        },
        &#39;angular&#39;: {
          deps: [&#39;jquery&#39;],
          exports: &#39;angular&#39;
        },
        &#39;underscore&#39;: {
          exports: &#39;_&#39;
        },
        &#39;angularRoute&#39;: [&#39;angular&#39;],
        &#39;angularCookies&#39;: [&#39;angular&#39;],
        &#39;bootstrap&#39;: [&#39;jquery&#39;]
      },
      paths: {
        &#39;requirejs&#39;: &#39;../lib/requirejs/require&#39;,
        &#39;jquery&#39;: &#39;../lib/jquery/jquery&#39;,
        &#39;underscore&#39;: &#39;../lib/underscorejs/underscore&#39;,
        &#39;angular&#39;: &#39;../lib/angularjs/angular&#39;,
        &#39;angularRoute&#39;: &#39;../lib/angularjs/angular-route&#39;,
        &#39;angularCookies&#39;: &#39;../lib/angularjs/angular-cookies&#39;,
        &#39;bootstrap&#39;: &#39;../lib/bootstrap/js/bootstrap&#39;,
        &#39;jsRoutes&#39;: &#39;/jsroutes&#39;,
        &#39;core&#39;: &#39;./core&#39;
      },
      modules: [
        {
          name: &#39;core&#39;
        }
      ]
    });

And finally, here&#39;s my *core.js* module:

    define([&#39;angular&#39;, &#39;angularRoute&#39;, &#39;underscore&#39;, &#39;bootstrap&#39;], function() {
      // core dependencies are loaded...
    });

After running `activator clean stage` from the command line I was hoping the built *core.js* file would include all my specified dependencies concatenated and minified into a single file, but it doesn&#39;t include any of them. If I specify a non-WebJar file as a dependency for *core.js*, it does optimize that correctly.

Is what I&#39;m trying to do possible? I&#39;ve been googling quite a bit and haven&#39;t been able to find a clear answer either way.

Thanks!

Optimizing JS from WebJars using sbt-rjs in a Play 2.3.x app

In Scala, algebraic data types are encoded as `sealed` one-level type hierarchies. Example:

&lt;!-- language: haskell --&gt;

    -- Haskell
    data Positioning a = Append
                       | AppendIf (a -&gt; Bool)
                       | Explicit ([a] -&gt; [a]) 

&lt;!-- language: scala --&gt;

    // Scala
    sealed trait Positioning[A]
    case object Append extends Positioning[Nothing]
    case class AppendIf[A](condition: A =&gt; Boolean) extends Positioning[A]
    case class Explicit[A](f: Seq[A] =&gt; Seq[A]) extends Positioning[A]

With `case class`es and `case object`s, Scala generates a bunch of things like `equals`, `hashCode`, `unapply` (used by pattern matching) etc that brings us many of the key properties and features of traditional ADTs.

There is one key difference though – **In Scala, &quot;data constructors&quot; have their own types**. Compare the following two for example (Copied from the respective REPLs).

&lt;!-- language: scala --&gt;

    // Scala

    scala&gt; :t Append
    Append.type
    
    scala&gt; :t AppendIf[Int](Function const true)
    AppendIf[Int]

    -- Haskell

    haskell&gt; :t Append
    Append :: Positioning a

    haskell&gt; :t AppendIf (const True)
    AppendIf (const True) :: Positioning a

---

I have always considered the Scala variation to be on the advantageous side.

After all, **there is no loss of type information**. `AppendIf[Int]` for instance is a subtype of `Positioning[Int]`.

&lt;!-- language: scala --&gt;

    scala&gt; val subtypeProof = implicitly[AppendIf[Int] &lt;:&lt; Positioning[Int]]
    subtypeProof: &lt;:&lt;[AppendIf[Int],Positioning[Int]] = &lt;function1&gt;

In fact, **you get an additional compile time invariant about the value**. (Could we call this a limited version of dependent typing?) 

This can be put to good use – Once you know what data constructor was used to create a value, the corresponding type can be propagated through rest of the flow to add more type safety. For example, Play JSON, which uses this Scala encoding, will only allow you to extract `fields` from `JsObject`, not from any arbitrary `JsValue`.

&lt;!-- language: scala --&gt;

    scala&gt; import play.api.libs.json._
    import play.api.libs.json._
    
    scala&gt; val obj = Json.obj(&quot;key&quot; -&gt; 3)
    obj: play.api.libs.json.JsObject = {&quot;key&quot;:3}
    
    scala&gt; obj.fields
    res0: Seq[(String, play.api.libs.json.JsValue)] = ArrayBuffer((key,3))
    
    scala&gt; val arr = Json.arr(3, 4)
    arr: play.api.libs.json.JsArray = [3,4]
    
    scala&gt; arr.fields
    &lt;console&gt;:15: error: value fields is not a member of play.api.libs.json.JsArray
                  arr.fields
                      ^
    
    scala&gt; val jsons = Set(obj, arr)
    jsons: scala.collection.immutable.Set[Product with Serializable with play.api.libs.json.JsValue] = Set({&quot;key&quot;:3}, [3,4])

In Haskell, `fields` would probably have type `JsValue -&gt; Set (String, JsValue)`. Which means it will fail at runtime for a `JsArray` etc. This problem also manifests in the form of well known partial record accessors. 

**The view that Scala&#39;s treatment of data constructors is wrong has been expressed numerous times** – on Twitter, mailing lists, IRC, SO etc. Unfortunately I don&#39;t have links to any of those, except for a couple - [this answer][1] by Travis Brown, and [Argonaut][2], a purely functional JSON library for Scala.

Argonaut [consciously][3] takes the Haskell approach (by `private`ing case classes, and providing data constructors manually). You can see that the problem I mentioned with Haskell encoding exists with Argonaut as well. (Except it uses `Option` to indicate partiality.)

&lt;!-- language: scala --&gt;

    scala&gt; import argonaut._, Argonaut._
    import argonaut._
    import Argonaut._
    
    scala&gt; val obj = Json.obj(&quot;k&quot; := 3)
    obj: argonaut.Json = {&quot;k&quot;:3}

    scala&gt; obj.obj.map(_.toList)
    res6: Option[List[(argonaut.Json.JsonField, argonaut.Json)]] = Some(List((k,3)))
    
    scala&gt; val arr = Json.array(jNumber(3), jNumber(4))
    arr: argonaut.Json = [3,4]
    
    scala&gt; arr.obj.map(_.toList)
    res7: Option[List[(argonaut.Json.JsonField, argonaut.Json)]] = None


I have been pondering this for quite some time, but still do not understand what makes Scala&#39;s encoding wrong. Sure it hampers type inference at times, but that does not seem like a strong enough reason to decree it wrong. What am I missing?


  [1]: https://stackoverflow.com/questions/25222215/scala-type-based-list-partitioning/25223200#25223200
  [2]: http://argonaut.io/
  [3]: http://mth.io/slides/argonaut/#/18
  [4]: http://mth.io/slides/argonaut/#/

What are the problems with an ADT encoding that associates types with data constructors? (Such as Scala.)

Kinda silly question, but I used [Activator][1] to get started with the play framework, and now need to see what version I&#39;m using. 2.3 came out with support for docker, but when I put 

`dockerExposedPorts in Docker := Seq(9000, 9443)`

in my `build.sbt`, it complains it doesn&#39;t know what dockerExposedPorts is, so I&#39;m thinking I might be running 2.2. 


  [1]: https://typesafe.com/activator

How to find out which Play version I&#39;m using?

I created a new Play Framework project using the activator, `activator new my-project-name` and  then I selected the `play-java` template and the project is created with no errors.

Then I import the project into my IDE, IntelliJ, as a SBT project. When the project is imported a popup is shown saying: `SBT compilation for play framework 2.x disabled by default`.

On IntelliJ project&#39;s panel it doesn&#39;t show all (mostly the files with the code) files. Just a handful of them.

[![enter image description here][1]][1]

The build.sbt file looks like full of compilation error (pretty much all the lines are red underlined).

Here&#39;s the build.sbt file

    name := &quot;&quot;&quot;my-project-name&quot;&quot;&quot;
    
    version := &quot;1.0-SNAPSHOT&quot;
    
    lazy val root = (project in file(&quot;.&quot;)).enablePlugins(PlayJava)
    
    scalaVersion := &quot;2.11.6&quot;
    
    libraryDependencies ++= Seq(
      javaJdbc,
      cache,
      javaWs
    )
    
    // Play provides two styles of routers, one expects its actions to be injected, the
    // other, legacy style, accesses its actions statically.
    routesGenerator := InjectedRoutesGenerator
    
    
    fork in run := true

I can compile and run the code with `activator ui` with no errors. So, why isn&#39;t IntelliJ fully importing the project and it shows me `SBT compilation for play framework 2.x disabled by default` message?

I googled around and couldn&#39;t find any hint related to this so I&#39;m kinda lost here. 


**EDIT: -------------------------------------**

I closed the project on IntelliJ and deleted the project folder. Closed IntelliJ and using `activator` I created again the same project. Using `activator ui` I compiled the project. Then I fired up IntelliJ and was prompted to either open a project, create a new one or import a project.

Selected import a project and did the normal &quot;import a project steps&quot; and IntelliJ imported the project with no hassle. **But** if I try to import the project while with an open project on IntelliJ I get the same problem that lead me to make this question. Maybe this is a bug on IntelliJ?


**EDIT 2 ------------------------------------------**

The solution to these two problems (the &quot;*SBT compilation for play framework 2.x disabled by default*&quot; and the files not showing on IntelliJ) can be fixed with `user3384225` and `DarkShadow` answers.

  [1]: http://i.stack.imgur.com/LRvz5.png

SBT compilation for play framework 2.x disabled by default

I&#39;d like to know your experience finding a host for play applications on free or low-cost servers

So far now I found the following options:

- [Playapps][1] (discontinued)

    A cloud hosting solution by zenexity, the company behind play framework  
    module: http://www.playframework.org/modules/playapps-1.4/home  
    princing: http://www.playapps.net/pricing

- [Google Application Engine][2]

    module: http://www.playframework.org/modules/gae-1.4/home  
    cons: can&#39;t use mysql, should not use JPA  
    Instead of JPA it is advised to use siena   
    http://www.playframework.org/modules/siena-2.0.0/home
    
    nice example: http://viralpatel.net/blogs/2011/01/first-play-framework-gae-siena-application-tutorial-example.html

- [Cloudbees][3]

    module: http://www.playframework.org/modules/cloudbees  
    floss: http://www.cloudbees.com/foss/  
    tutorial: http://wiki.cloudbees.com/bin/view/RUN/Playframework

- [dotCloud][4]

    module: http://www.playframework.org/modules/cloudbees  
    princing: https://www.dotcloud.com/pricing/  
    (there&#39;s a free plan with 10MB db)  

- [AWS - Amazon Web Services][5] 

    pricing: http://aws.amazon.com/en/ec2/#pricing  
    pricing: http://aws.amazon.com/en/elasticbeanstalk/#pricing  
    samples:  
    http://www.ibm.com/developerworks/java/library/j-javadev2-19/index.html  
    http://www.ibm.com/developerworks/java/library/j-javadev2-16/index.html

- [Heroku for play!][6]

    princing: http://blog.heroku.com/archives/2011/8/29/play/   
    (seems like you get 1 web dyno + 5mb postresql dabate for free)  
    sample: http://devcenter.heroku.com/articles/play

Do you have any experience with one of these?

Any other option you know?


  [1]: http://www.playapps.net/
  [2]: http://code.google.com/intl/en/appengine/
  [3]: http://www.cloudbees.com/
  [4]: https://www.dotcloud.com/
  [5]: http://aws.amazon.com/
  [6]: http://blog.heroku.com/archives/2011/8/29/play/






Experiences on free and low-cost hosting for play framework applications?

I&#39;ve just stumbled upon the following new java web framework: Play

http://www.playframework.org/

http://www.playframework.org/documentation/1.0/home


with such a stunning list of features, I&#39;m pretty much surprised I haven&#39;t heard of it before...

Sounds like the java web development promised land...

has anybody tried it? any real experience with it? do you think it&#39;s worth studying it?


any experience with &quot;Play&quot; java web development framework?

I want to add an object to the Global scope, and in order to construct it I need to pass it a path to a file.
I don&#39;t want to hard code the file path in the source, and so I want to get that path from the application.conf.

The problem is that I don&#39;t know how to access these properties from the java class.
I tried this:

    Configuration.root().getString(&quot;file.path&quot;)

But it ends with a *NullPointerException*.

Am I wrong in assuming that there&#39;s a global Configuration instance that I can use?
Thanks.

Accessing the application.conf properties from java class with Play! 2.0

We have a Play 1.2.4 application and we got Jenkins (on Ubuntu) for the application. We&#39;re having problems with Cobertura. 

After running the tests (succesfully), every now and then, we get  the following error:

    ---------------------------------------
    java.lang.reflect.InvocationTargetException
            at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
            at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
            at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
            at java.lang.reflect.Method.invoke(Method.java:597)
            at net.sourceforge.cobertura.util.FileLocker.lock(FileLocker.java:124)
            at play.modules.cobertura.CoberturaPlugin$CoberturaPluginShutdownThread.run(Unknown Source)
    Caused by: java.nio.channels.OverlappingFileLockException
            at sun.nio.ch.FileChannelImpl$SharedFileLockTable.checkList(FileChannelImpl.java:1166)
            at sun.nio.ch.FileChannelImpl$SharedFileLockTable.add(FileChannelImpl.java:1068)
            at sun.nio.ch.FileChannelImpl.lock(FileChannelImpl.java:824)
            at java.nio.channels.FileChannel.lock(FileChannel.java:860)
            ... 6 more
    ---------------------------------------
    Unable to get lock on /var/lib/jenkins/jobs/project/workspace/cobertura.ser.lock: null
    This is known to happen on Linux kernel 2.6.20.
    Make sure cobertura.jar is in the root classpath of the jvm 
    process running the instrumented code.  If the instrumented code 
    is running in a web server, this means cobertura.jar should be in 
    the web server&#39;s lib directory.
    Don&#39;t put multiple copies of cobertura.jar in different WEB-INF/lib directories.
    Only one classloader should load cobertura.  It should be the root classloader.
    ---------------------------------------
    lock file could not be deleted

This doesn&#39;t seem to &quot;break the build&quot; but further down the build, we get the following (which causes the cobertura reports to fail)

    Publishing Cobertura coverage report...
    No coverage results were found using the pattern &#39;test-result/code-coverage/coverage.xml&#39; relative to &#39;/var/lib/jenkins/jobs/project/workspace&#39;.  Did you enter a pattern relative to the correct directory?  Did you generate the XML report(s) for Cobertura?
    Build step &#39;Publish Cobertura Coverage Report&#39; changed build result to FAILURE

Running a subsequent build manually usually passes.

According to https://stackoverflow.com/questions/2148886/zero-code-coverage-with-cobertura-1-9-2-but-tests-are-working , I tried setting *-Dcobertura.use.java.nio=false* after play auto-test -command.

As this error was happening only now and then, I&#39;m not totally sure if this helped. But after that, we got a problem with play auto-test hanging:

      ...
      Executing /opt/play-1.2.4/play auto-test &quot;/var/lib/jenkins/jobs/project/workspace&quot;  -Dcobertura.use.java.nio=false
      [workspace] $ /opt/play-1.2.4/play auto-test &quot;/var/lib/jenkins/jobs/project/workspace&quot; -Dcobertura.use.java.nio=false
      &lt;build stuck here for a couple of days&gt;

Since nothing has been totally deterministic, it&#39;s a bit difficult to say about causalities here. (This seems to happen after one or two builds after jenkins/server restart)

Currently I&#39;m considering disabling Cobertura in our project, but if somebody has other ideas, that would be great =)

Jenkins + Play 1.2.4 : problems with cobertura lock files / report

I was making my way through the Scala playframework tutorial and I came across this snippet of code which had me puzzled: 

    def newTask = Action { implicit request =&gt;
    taskForm.bindFromRequest.fold(
            errors =&gt; BadRequest(views.html.index(Task.all(), errors)),
            label =&gt; {
              Task.create(label)
              Redirect(routes.Application.tasks())
            } 
      )
    }

So I decided to investigate and came across [this post][1].

I still don&#39;t get it.

What is the difference between this: 

    implicit def double2Int(d : Double) : Int = d.toInt

and

    def double2IntNonImplicit(d : Double) : Int = d.toInt

other than the obvious fact they have different method names.

When should I use `implicit` and why?

  [1]: http://pietrowski.info/2009/07/scala-implicit-conversion/

Understanding implicit in Scala

I am just getting started with Play Framework. I have downloaded and installed play and created a sample java application. When I try to start the play console in the application directory it hangs at &quot;Loading project definition&quot;.

    PS C:\dev\play\javatest&gt; play.bat
    Getting org.scala-sbt sbt_2.9.1 0.11.3 ...
    :: retrieving :: org.scala-sbt#boot-app
            confs: [default]
            37 artifacts copied, 0 already retrieved (7245kB/283ms)
    [info] Loading project definition from C:\dev\play\myFirstApp\project

When i try running a Scala application i get a message about it waiting for a lock:

    PS C:\dev\play\scalatest&gt; play
    [info] Loading project definition from C:\dev\play\test1\project
    Waiting for lock on C:\lib\play\repository\.sbt.ivy.lock to be available...

Running Windows 7, JDK 1.7.0_05 and Play Framework 2.0.2. Any ideas?

Play framework hangs on startup at: &quot;Loading project definition from&quot;

[Play&#39;s home page](http://www.playframework.com/) says:

&gt; Built on Akka, Play provides predictable and minimal resource consumption (CPU, memory, threads) for highly-scalable applications.

I&#39;d like to know exactly how and where Akka is used in Play and what are the consequences of having Play build on top of Akka.

All Playframework Solutions on Gang of Coders

Total of 27 Playframework Solutions