Java Magazine, July/August 2018

ORACLE COM JAVAMAGAZINE JULY AUGUST 2018 87 fix this In this example its not abundantly clear whether the problem is that theres an abstract method declared in a concrete class or that a nonabstract class surrounds an abstract method Of course the perspective you take on this determines where you think the error is located either in public class Car or in the declaration of the abstract accelerate method In its current form the compiler actually reports the problem in terms of the class being in error because it fails to provide concrete implementations for all its methods However for this question it seemed easier to simply ofer the suggestion that the class doesnt compile Such a form isnt very likely in the real exam so be aware that if two separate elements of syntax are mutually exclusive you should be ready to consider either of them as the cause of the problem article Simon Roberts joined Sun Microsystems in time to teach Suns first Java classes in the UK He created the Sun Certified Java Programmer and Sun Certified Java Developer exams He wrote several Java certification guides and is currently a freelance educator who publishes recorded and live video training through Pearson InformIT available direct and through the OReilly Safari Books Online service He remains involved with Oracles Java certification projects Mikalai Zaikin is a lead Java developer at IBA IT Park in Minsk Belarus During his career he has helped Oracle with development of Java certification exams and he has been a technical reviewer of several Java certification books including three editions of the famous Sun Certified Programmer for Java study guides by Kathy Sierra and Bert Bates java proposals of interest JEP 335 Deprecate the Nashorn JavaScript Engine This proposal made in May 2018 puts forth the idea of deprecating the engine added in Java 8 that provides application users a way to script inside Java apps In this way Nashorn pronounced nas horn provides functionality similar to what Lua provides to C programs You might recall that Nashorn was added to Java 8 as a replacement for its slower predecessor the Rhino engine Both products are implementations of the Java scripting interface which defines a mechanism that enables scripting and specifies how data is moved between the engine and the host Java application Although Nashorn and Rhino support JavaScript scripting engines exist for other languages such as Groovy and Ruby JEP 335 does not propose deprecating the scripting engine technology but rather just the JavaScript implementation The primary driver is that JavaScript itself is evolving and to provide full support for the language requires considerable developer resources for apps that might not need the new features To wit Nashorn currently supports the ECMAScript version 51 However ECMAScript 2016 and 2017 await implementation JEP 335 currently is only a proposal According to the authors part of the rationale for this proposal is to see whether developers outside of Oracle might be interested in working on Nashorn In any event all code that presently works with Nashorn would continue to do so for the foreseeable future More on the status of JEP 335 will be posted as comments are received