NPE в AbstractSearchScript при использовании из ScriptEngineService

[ponimas (Alexander Ponimaskin)]

Здравствуйте!
Пытаюсь разобраться со script engine.
Написал такой вот минимальный пример.

    private static class MyScriptEngine implements ScriptEngineService {
        @Override
        public String getType() {
            return "scripts";
        }

        @Override
        public Function<Map<String,Object>, SearchScript> compile(String scriptName, String scriptSource, Map<String, String> params) {
            return p -> new SearchScript() {
                    @Override
                    public boolean needsScores() {
                        return false;
                    }

                    @Override
                    public LeafSearchScript getLeafSearchScript(LeafReaderContext context) throws IOException {
                        return new AbstractSearchScript() {
                            @Override
                            public Object run() {
                                System.out.println("Booo");
                                return 1;
                            }
                        };
                    }
                };
        }

        @Override
        @SuppressWarnings("unchecked")
        public SearchScript search(CompiledScript compiledScript, SearchLookup lookup, @Nullable Map<String, Object> params) {
            Function<Map<String,Object>, SearchScript> scriptFactory = (Function<Map<String,Object>,SearchScript>) compiledScript.compiled();
            return scriptFactory.apply(params);
        }

        @Override
        public ExecutableScript executable(CompiledScript compiledScript, @Nullable Map<String, Object> params) {
            throw new UnsupportedOperationException();

        }

        @Override
        public boolean isInlineScriptEnabled() {
            return true;
        }

        @Override
        public void close() {
        }
    }

пытаюсь получить скриптовое поле

{
    "_source": false,
    "query": {
    },
    "script_fields": {
        "test": {
            "script": {
                "source": "_",
                "lang": "scripts",
                "params": {
                }
            }
        }
    }
}

но получаю NPE.

_{[2017-10-20T19:47:42,171][DEBUG][o.e.a.s.TransportSearchAction] [8nIomLL] [4] Failed to execute fetch phase org.elasticsearch.transport.RemoteTransportException: [8nIomLL][127.0.0.1:9300][indices:data/read/search[phase/fetch/id]] Caused by: java.lang.NullPointerException at org.elasticsearch.script.AbstractSearchScript.setDocument(AbstractSearchScript.java:115) ~[elasticsearch-5.6.3.jar:5.6.3] at org.elasticsearch.search.fetch.subphase.ScriptFieldsFetchSubPhase.hitExecute(ScriptFieldsFetchSubPhase.java:47) ~[elasticsearch-5.6.3.jar:5.6.3] at org.elasticsearch.search.fetch.FetchPhase.execute(FetchPhase.java:165) ~[elasticsearch-5.6.3.jar:5.6.3] at org.elasticsearch.search.SearchService.executeFetchPhase(SearchService.java:426) ~[elasticsearch-5.6.3.jar:5.6.3] at org.elasticsearch.action.search.SearchTransportService$12.messageReceived(SearchTransportService.java:407) ~[elasticsearch-5.6.3.jar:5.6.3] at org.elasticsearch.action.search.SearchTransportService$12.messageReceived(SearchTransportService.java:404) ~[elasticsearch-5.6.3.jar:5.6.3] at org.elasticsearch.transport.RequestHandlerRegistry.processMessageReceived(RequestHandlerRegistry.java:69) ~[elasticsearch-5.6.3.jar:5.6.3] at org.elasticsearch.transport.TransportService$7.doRun(TransportService.java:644) [elasticsearch-5.6.3.jar:5.6.3] at org.elasticsearch.common.util.concurrent.ThreadContext$ContextPreservingAbstractRunnable.doRun(ThreadContext.java:638) [elasticsearch-5.6.3.jar:5.6.3] at org.elasticsearch.common.util.concurrent.AbstractRunnable.run(AbstractRunnable.java:37) [elasticsearch-5.6.3.jar:5.6.3] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [?:1.8.0_112] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [?:1.8.0_112] at java.lang.Thread.run(Thread.java:745) [?:1.8.0_112]}

Что я делаю не так?

[Igor_Motov]

У вас leafLookup не установелен после создания AbstractSearchScript. Посмотрите пример тут.

[ponimas (Alexander Ponimaskin)]

АsetLookup ведь не публичный метод, как в этом случае поступить?

Возможно я глупости спрашиваю, прошу заранее извинить.

[Igor_Motov]

Вам не обязательно использовать AbstractSearchScript, главное реализовать LeafSearchScript. Например, как в JavaScriptSearchScript.