How to Enable JavaScript Querying in Druid Database

if you not configuring your project you may get following error.

Error : Unknown exception / JavaScript is disabled / java.lang.IllegalStateException

So first we have to configuring our druid server.
follow the following steps to solve it.

• if you running the druid server first you have to stop or kill the server.
• use Ctrl + [C] to kill the server.
• after change your directory to ( this only valid if your are using micro server, if using nano or small or medium or large or xlarge servers first you have to select relevant for find the right "common.runtime.properties" file.)
• Server_Project_Name/conf/druid/single-server/micro-quickstart/_common 
• And you can find a common.runtime.properties in the current directory.
• open that file using text-editor or anything and go down and add following line
• druid.javascript.enabled = true
• Now all setup for run JavaScript Querying in Druid Database, change your directory to root folder (server folder) and run ./bin/start-micro-quickstart to start the druid server again.