NPE not specified for javax.script.ScriptEngine.setContext(ScriptContext ctxt) and it is not thrown by realized javax.script.AbstractScriptEngine.setContext(ScriptContext ctxt).

The protected context field of ScriptEngine cannot be null in any case, if it will be null, NPE actually will be thrown by calling any of eval() methods with valid parameters.

So, NPE throwing should be specified for setContext(ScriptContext ctxt) method of javax.script.ScriptEngine interface and should be realized in javax.script.AbstractScriptEngine.setContext(ScriptContext ctxt).