How to transform Play project as Eclipse project

To transform a new Play project into Eclipse workspace.
the following steps can be followed.

1. navigate into the play project root directory. eg. C:\my-play-project

2. add the following plugin into the end of project/plugins.sbt

addSbtPlugin("com.typesafe.sbteclipse" % "sbteclipse-plugin" % "5.2.2")

3. add the following configuration into the end of build.sbt

EclipseKeys.preTasks := Seq(compile in Compile, compile in Test)
EclipseKeys.projectFlavor := EclipseProjectFlavor.Java  
EclipseKeys.createSrc := EclipseCreateSrc.ValueSet(EclipseCreateSrc.ManagedClasses, EclipseCreateSrc.ManagedResources) 

How to create new Play Java project

1. make sure sbt is installed in your OS
2. create a new folder, eg. "my-play-project"
3. open command prompt, and navigate to the newly create folder
4. in the command prompt, type "sbt new playframework/play-java-seed.g8"
  a) enter project name
  b) enter organization
  c) enter scala version
  d) enter play version
  e) enter sbt version

How to easily get logged in user in Liferay.

ServiceContextThreadLocal.getServiceContext().getUserId();


reference:
http://liferay-hacks.blogspot.my/2014/01/get-current-logged-in-user-easily-in.html