The following specification http://docs.oracle.com/javase/8/docs/api/javax/script/ScriptEngineFactory.html#getParameter-java.lang.String- says: --- Keys for which the value is defined in all implementations are: ScriptEngine.ENGINE ScriptEngine.ENGINE_VERSION ScriptEngine.NAME ScriptEngine.LANGUAGE ScriptEngine.LANGUAGE_VERSION The values for these keys are the Strings returned by getEngineName, getEngineVersion, getName, getLanguageName and getLanguageVersion respectively. --- This part of the text is not correct regarding getName() method since there is no such method in the current API. Yet the following method exists: http://docs.oracle.com/javase/8/docs/api/javax/script/ScriptEngineFactory.html#getNames--