How can I retrieve the _id elasticsearch field information using Java API? I know I can see this information with head plugin, looking to documents, but it's not necessary for me.
I'm developing a Java project, and all commands, like update, delete, require this _id value. But how can I get it?
Thanks in advance
When executing a search, you get back an object SearchResponse. By calling the method getHits() you get back a list of objects of type SearchHit. This object has a method id().
SearchResponse searchResponse = client.prepareSearch().setQuery(matchAllQuery()).get();
for (SearchHit hit : searchResponse.getHits()) {
String yourId = hit.id();
}
Related
I'm using hibernate-search-elasticsearch 5.8.2.Final and I can't figure out how to get script fields:
https://www.elastic.co/guide/en/elasticsearch/reference/5.6/search-request-script-fields.html
Is there any way to accomplish this functionality?
This is not possible in Hibernate Search 5.8.
In Hibernate Search 5.10 you could get direct access to the REST client, send a REST request to Elasticsearch and get the result as a JSON string that you would have to parse yourself, but it is very low-level and you would not benefit from the Hibernate Search search APIs at all (no query DSL, no managed entity loading, no direct translation entity type => index name, ...).
If you want better support for this feature, don't hesitate to open a ticket on our JIRA, describing in details what you are trying to achieve and how you would have expected to be able to do that. We are currently working on Search 6.0 which brings a lot of improvements, in particular when it comes to using native features of Elasticsearch, so it just might be something we could slip into our backlog.
EDIT: I forgot to mention that, while you cannot use server-side scripts, you can still get the full source from your documents, and do some parsing in your application to achieve a similar result. This will work even in Search 5.8:
FullTextEntityManager fullTextEm = Search.getFullTextEntityManager(entityManager);
FullTextQuery query = fullTextEm.createFullTextQuery(
qb.keyword()
.onField( "tags" )
.matching( "round-based" )
.createQuery(),
VideoGame.class
)
.setProjection( ElasticsearchProjectionConstants.SCORE, ElasticsearchProjectionConstants.SOURCE );
Object[] projections = (Object[]) query.getSingleResult();
for (Object projection : projections) {
float score = (float) projection[0];
String source = (String) projection[1];
}
See this section of the documentation.
Does anyone ever used the Retrieve & Rank service with Java SDK (Rank service particularly) ?
I want to understand how it works because some points seem me not logical :
What is the difference between the Java approach, where we must execute a search query with Apache Solr, and then call the method rank; and the CURL approach, where we just have to run a single query?
Why the method rank takes a CSV file that contains results from the search query whereas we apparently cannot have the result of a search query in CSV?
I did not find my responses neitheir in this documentation nor in this example.
Thanks for your time.
I have never used Retrieve and Rank before but by reading the documentation here are my thoughts
I do not think that there any difference between Java approach and CURL. From what I understand Search and rank in curl uses this command
curl -u "{username}":"{password}" "https://gateway.watsonplatform.net/retrieve-and-rank/api/v1/solr_clusters/sc1ca23733_faa8_49ce_b3b6_dc3e193264c6/solr/example_collection/fcselect?ranker_id=B2E325-rank-67&q=what%20is%20the%20basic%20mechanism%20of%20the%20transonic%20aileron%20buzz&wt=json&fl=id,title"
while in Java
RetrieveAndRank service = new RetrieveAndRank();
service.setUsernameAndPassword("{username}","{password}");
HttpSolrClient solrClient = new HttpSolrClient;
solrClient = getSolrClient(service.getSolrUrl("scfaaf8903_02c1_4297_84c6_76b79537d849"), "{username}","{password}");
SolrQuery query = new SolrQuery("what is the basic mechanism of the transonic aileron buzz");
QueryResponse response = solrClient.query("example_collection", query);
Ranking ranking = service.rank("B2E325-rank-67", response);
System.out.println(ranking);
I think what the curl command would do, at the back end it would fire a search in Solr using the query specified and after the results returned it would rank them.
In Java this is done explicitly, instead of having a method queryAndRank you have two methods, one that is going to run in Solr, get the results from there and then forward these results to ranking system.
The search in Solr can return csv.
The CSVResponseWriter can write the list of documents in a response in
CSV format.
http://wiki.apache.org/solr/CSVResponseWriter
I'm having a problem with MongoDB using Java when I try adding documents with customized _id field. And when I insert new document to that collection, I want to ignore the document if it's _id has already existed.
In Mongo shell, collection.save() can be used in this case but I cannot find the equivalent method to work with MongoDB java driver.
Just to add an example:
I have a collection of documents containing websites' information
with the URLs as _id field (which is unique)
I want to add some more documents. In those new documents, some might be existing in the current collection. So I want to keep adding all the new documents except for the duplicate ones.
This can be achieve by collection.save() in Mongo Shell but using MongoDB Java Driver, I can't find the equivalent method.
Hopefully someone can share the solution. Thanks in advance!
In the MongoDB Java driver, you could try using the BulkWriteOperation object with the initializeOrderedBulkOperation() method of the DBCollection object (the one that contains your collection). This is used as follows:
MongoClient mongo = new MongoClient("localhost", port_number);
DB db = mongo.getDB("db_name");
ArrayList<DBObject> objectList; // Fill this list with your objects to insert
BulkWriteOperation operation = col.initializeOrderedBulkOperation();
for (int i = 0; i < objectList.size(); i++) {
operation.insert(objectList.get(i));
}
BulkWriteResult result = operation.execute();
With this method, your documents will be inserted one at a time with error handling on each insert, so documents that have a duplicated id will throw an error as usual, but the operation will still continue with the rest of the documents. In the end, you can use the getInsertedCount() method of the BulkWriteResult object to know how many documents were really inserted.
This can prove to be a bit ineffective if lots of data is inserted this way, though. This is just sample code (that was found on journaldev.com and edited to fit your situation.). You may need to edit it so it fits your current configuration. It is also untested.
I guess save is doing something like this.
fun save(doc: Document, col: MongoCollection<Document>) {
if (doc.getObjectId("_id") != null) {
doc.put("_id", ObjectId()) // generate a new id
}
col.replaceOne(Document("_id", doc.getObjectId("_id")), doc)
}
Maybe they removed save so you decide how to generate the new id.
I have been trying to retrieve information from querying a specific Asset(Story/Defect) on V1 using the VersionOne.SDK.Java.APIClient. I have been able to retrieve information like ID.Number, Status.Name but not Requests.Custom_SFDCChangeReqID2 under a Story or a Defect.
I check the metadata for:
https://.../Story?xsl=api.xsl
https://.../meta.V1/Defect?xsl=api.xsl
https://.../meta.V1/Request?xsl=api.xsl
And the naming and information looks right.
Here is my code:
IAssetType type = metaModel.getAssetType("Story");
IAttributeDefinition requestCRIDAttribute = type.getAttributeDefinition("Requests.Custom_SFDCChangeReqID2");
IAttributeDefinition idNumberAttribute = type.getAttributeDefinition("ID.Number")
Query query = new Query(type);
query.getSelection().add(requestCRIDAttribute);
query.getSelection().add(idNumberAttribute);
Asset[] results = v1Api.retrieve(query).getAssets();
String RequestCRID= result.getAttribute(requestCRIDAttribute).getValue().toString();
String IdNumber= result.getAttribute(idNumberAttribute).getValue().toString();
At this point, I can get some values for ID.Number but I am not able to retrieving any information for the value Custom_SFDCChangeReqID2.
When I run the restful query to retrieve information using a browser from a server standpoint it works and it does retrieve the information I am looking for. I used this syntax:
https://.../rest-1.v1/Data/Story?sel=Number,ID,Story.Requests.Custom_SFDCChangeReqID2,Story.
Alex: Remember that Results is an array of Asset´s, so I guess you should be accessing the information using something like
String RequestCRID= results[0].getAttribute(requestCRIDAttribute).getValue().toString();
String IdNumber= results[0].getAttribute(idNumberAttribute).getValue().toString();
or Iterate through the array.
Also notice that you have defined:
Asset[] results and not result
Hi thanks for your answer! I completely forgot about representing the loop, I was too focus on the retriving information part, yes I was actually using a loop and yes I created a temporary variable to check what I was getting from the query in the form
Because I was getting the variables one by one so I was only using the first record. My code works after all. It was just that What I was querying didn't contain any information of my use, that's why I was not finding any. Anyway thanks for your comment and observations
I'm new to Elasticsearch and tried to query some sample documents. I issued the following query using the Java API. This query fetched me the correct result. It returned the names of all categories. Now I want the count of all names of a category. Could you explain me how to do that? I'm sorry for my bad English.
SearchResponse sr = client.prepareSearch()
.addField("Category")
.setQuery(QueryBuilders.matchAllQuery())
.addFacet(FacetBuilders.termsFacet("f")
.field("Category"))
.execute()
.actionGet();
Look at the Count API to count your results if you not want to get the result set (matched documents) but only the count.
If you want to get the result set, you get the result size in the response for every filter or query request too.