JEP 335: Deprecate the Nashorn JavaScript Engine

Owner	Jim Laskey
Created	2018/05/08 14:23
Updated	2018/06/06 20:28
Type	Feature
Status	Candidate
Component	core-libs / jdk.nashorn
Scope	JDK
Discussion	jdk dash dev at openjdk dot java dot net
Effort	S
Priority	3
Reviewed by	Alex Buckley, Brian Goetz, Dalibor Topic
Issue	8202786

Summary

Deprecate the Nashorn JavaScript script engine and APIs, and the jjs tool.

Motivation

The Nashorn JavaScript engine was first incorporated into JDK 8 via JEP 174 as a replacement for the Rhino scripting engine. When it was released, it was a complete implementation of the ECMAScript-262 5.1 standard.

With the rapid pace at which ECMAScript language constructs, along with APIs, are adapted and modified, we have found Nashorn challenging to maintain.

Non-Goals

This deprecation does not affect, in any way, the javax.script API.

Description

Three JDK modules will be terminally deprecated, that is, annotated with @Deprecated(forRemoval=true):

jdk.scripting.nashorn -- contains the jdk.nashorn.api.scripting and jdk.nashorn.api.tree packages.
jdk.scripting.nashorn.shell -- contains the jjs tool. Running jjs will display a warning:

Warning: The jjs tool is planned to be removed from a future JDK release.
jdk.dynalink -- contains the Dynalink support library.

A separate JEP will be filed for the actual removal of the types and modules in a future JDK feature release.

Alternatives

GraalJS using Oracle Labs' Truffle technology may soon be publicly available as a Java module. It is understood that GraalJS provides most of the same functionality as Nashorn along with better performance.

Risks and Assumptions

The risk of removing Nashorn is that certain applications will no longer run because of the expectation that JavaScript is present. The breadth of Nashorn usage has not been easy to track. It is hoped that feedback for this JEP might provide better insight into actual Nashorn usage.