Elasticsearch插件和访问请求对象

Question

I'm new to elasticsearch and am trying to figure out to access/use elastic requests/responses in a plugin. I have an action that needs to know about term statistics, so I looked up and found there is a termvector request and response object/s. In the prepareRequest method of my code I'm trying to figure out how to access it.

    @Override
protected RestChannelConsumer prepareRequest(RestRequest request, NodeClient client) throws IOException {
    LOGGER.info("Handle _custom endpoint");
    GetRequest req = new GetRequest(request.param("index"), request.param("type"), request.param("id"));
    TermVectorsRequest tvReq = new TermVectorsRequest(request.param("index"), request.param("type"), request.param("id"));
    //set to true to get total term stats
    tvReq.termStatistics(true);
    tvReq.selectedFields(request.param("field"));

    TermVectorsResponse tvResponse;
    GetResponse response;

    try {
        // Response that holds field contents, works great
        response = client.get(req).get();
        // Response that has stats, I think it needs a listener, no clue :(
        tvResponse = client.termVectors(tvReq).get();
        System.out.println("After: " + tvResponse.getFields().terms("after").getSumDocFreq());

        // Can ignore the rest of the code
        boolean fieldExists = response.getSource().containsKey(request.param("field"));
        if(fieldExists) {
            System.out.println(response.getSource().get(request.param("field")));
            return createMessageResponse(request, new SingleMessage("message", "Successfully did a thing!"));
        } else {
            return createMessageResponse(request, new SingleMessage("message", "Field \"" + request.param("field") + "\" does not exist."));
        }
    } catch (InterruptedException | ExecutionException e) {
        LOGGER.error(e);
    }

}

So I can use the getRequest object to get fields from a document which is great, but I'm having trouble accessing the termvector information. The getFields() is empty and I'm getting null. If I access the term vectors in kibana via the endpoint I get several terms, such as 'after'. Looking at the RestTermVectorsAction here at line 75 they use the second parameter of client.termVectors

return channel -> client.termVectors(termVectorsRequest, new RestToXContentListener<>(channel));

My issue here is I don't want to return that as I have other calculations to do and want to create my own return message, and I'm not sure if I can access this channel object otherwise...

So is this the right approach for accessing information(In this case term vectors) about an index inside an elasticsearch plugin? I've seen the searchRequest used in other actions so I feel it's correct, I'm just really unfamiliar with the actionListener and what's going on with it. If it is what do I need to do to get access my term vectors? I've tried returning an equivalent of line 75 and get the same output which means I need that action listener added to the client request, but I'm not sure how to get access to the RestChannel channel object to do so.

Also if this isn't the right approach what is?

Edit: I just realized that adding the listen makes the method void so I can't use that. I've found that using

tvResponse.getFields().terms("contents").getSumDocFreq()

works... which seems strange as that's the field name and not a term

Answer 1

It looks like the problem has nothing to do with the restchannel object. My problem is for some reason the getFields().terms("term here") only has the string "contents" as a term and not anything within it. I'm going to make a new question regarding this.