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How to access partition key from an existing table in cosmos db

I'm trying to access only partition key of an existing collection in cosmos db
I have gone through official doc and git hub links but no luck. Please help me.
Note: I'm able to successfully read and write data using java by using Document Client(SQL api)

Please try this code:
DocumentClient dClient = new DocumentClient(endPoint,primary_key,null,null);
String collectionLink = String.format("/dbs/%s/colls/%s", databaseId, collectionId);
ResourceResponse<DocumentCollection> response = dClient.readCollection(collectionLink,new RequestOptions());
DocumentCollection documentCollection = response.getResource();
PartitionKeyDefinition partitionKeyDefinition = documentCollection.getPartitionKey();
Collection<String> paths = partitionKeyDefinition.getPaths();
if(paths.iterator().hasNext()){
System.out.println(paths.iterator().next());
}

I found this works:
_container is the db container for cosmos.
var settings = await _container!.ReadContainerAsync(cancellationToken: cancellationToken);
var partitionKeyPath = settings.Resource.PartitionKeyPath[1..];
var partitionProperty = typeof(T).GetProperty(partitionKeyPath);
var partitionKey = partitionProperty!.GetValue(message)!.ToString();

How to get single GridFS file using Java driver 3.7+?

I need to get single the GridFS file using Java driver 3.7+.
I have two collections with file in a database: photo.files and photo.chunks.
The photo.chunks collection contains the binary file like:
The photo.files collection contains the metadata of the document.
To find document using simple database I wrote:
Document doc = collection_messages.find(eq("flag", true)).first();
String messageText = (String) Objects.requireNonNull(doc).get("message");
I tried to find file and wrote in same way as with an example above, according to my collections on screens:
MongoDatabase database_photos = mongoClient.getDatabase("database_photos");
GridFSBucket photos_fs = GridFSBuckets.create(database_photos,
"photos");
...
...
GridFSFindIterable gridFSFile = photos_fs.find(eq("_id", new ObjectId()));
String file = Objects.requireNonNull(gridFSFile.first()).getMD5();
And like:
GridFSFindIterable gridFSFile = photos_fs.find(eq("_id", new ObjectId()));
String file = Objects.requireNonNull(gridFSFile.first()).getFilename();
But I get an error:
java.lang.NullPointerException
at java.util.Objects.requireNonNull(Objects.java:203)
at project.Bot.onUpdateReceived(Bot.java:832)
at java.util.ArrayList.forEach(ArrayList.java:1249)
Also I checked docs of 3.7 driver, but this example shows how to find several files, but I need single:
gridFSBucket.find().forEach(
new Block<GridFSFile>() {
public void apply(final GridFSFile gridFSFile) {
System.out.println(gridFSFile.getFilename());
}
});
Can someone show me an example how to realize it properly?
I mean getting data, e.g. in chunks collection by Object_id and md5 field also by Object_id in metadata collection.
Thanks in advance.

To find and use specific files:
photos_fs.find(eq("_id", objectId)).forEach(
(Block<GridFSFile>) gridFSFile -> {
// to do something
});
or as alternative, I can find specific field of the file.
It can be done firstly by creating objectId of the first file, then pass it to GridFSFindIterable object to get particular field and value from database and get finally file to convert into String.
MongoDatabase database_photos =
mongoClient.getDatabase("database_photos");
GridFSBucket photos_fs = GridFSBuckets.create(database_photos,
"photos");
...
...
ObjectId objectId = Objects.requireNonNull(photos_fs.find().first()).getObjectId();
GridFSFindIterable gridFSFindIterable = photos_fs.find(eq("_id", objectId));
GridFSFile gridFSFile = Objects.requireNonNull(gridFSFindIterable.first());
String file = Objects.requireNonNull(gridFSFile).getMD5();
But it checks files from photo.files not from photo.chunkscollection.
And I'm not sure that this way is code-safe, because of debug info, but it works despite the warning:
Inconvertible types; cannot cast 'com.mongodb.client.gridfs.model.GridFSFile' to 'com.mongodb.client.gridfs.GridFSFindIterableImpl'

find amazon categories using python

I would like to get the categories of the amazon ,I am planning to scrap not to use API.
I have scrapped the http://www.amazon.com.I have scraped all the categories and sub-categories under Shop By Department drop down .I have created a web service to do this The code is here
#route('/hello')
def hello():
text=list();
link=list();
req = urllib2.Request("http://www.amazon.com",
headers={"Content-Type": "application/json"})
html=urllib2.urlopen(req).read()
soup = BeautifulSoup(html)
last_page = soup.find('div', id="nav_subcats")
for elm in last_page.findAll('a'):
texts = elm.text
links = elm.get('href')
links = links.partition("&node=")[2]
text.append(texts)
link.append(links)
alltext=list();
for i,j in zip(text,link):
alltext.append({"name":i,"id":j})
response.content_type = 'application/json'
print(alltext)
return dumps(alltext)
run(host='localhost', port=8080, debug=True)
I am passing the category name and category id as a JSON object to one of my members to pass it to the API to get the product listing for each category
It is written in JAVA.Here is the code
for (int pageno = 1; pageno <= 10; pageno++) {
String page = String.valueOf(pageno);
String category_string = selectedOption.get("category_name").toString();
String category_id = selectedOption.get("category_id").toString();
final Map<String, String> params = new HashMap<String, String>(3);
params.put(AmazonClient.Op.PARAM_OPERATION, "ItemSearch");
params.put("SearchIndex", category_string);
params.put("BrowseNodeId", category_id);
params.put("Keywords", category_string);
params.put("ItemPage", page);
System.out.println(client.documentToString(client.getXml(params)));
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
Document doc = null;
DocumentBuilder db = dbf.newDocumentBuilder();
InputStream is = client.getInputStream(params);
doc = db.parse(is);
NodeList itemList = doc.getElementsByTagName("Items");
But i am getting this error when i pass the category id as the BrowseNodeId and category name as keyword and search index.
For example
Search Index and Keyword -Amazon Instant Video
BrowseNodeId-2858778011
The value you specified for SearchIndex is invalid. Valid values include [ 'All','Apparel',...................................reless','WirelessAccessories' ].
I would like to know from which amazon url i will get all the categories and its browse nodes
Thank you

I have never looked at Amazon's API before, so this is just a guess but, based on the error message it would seem that "Amazon Instant Video" is not a valid search index. Just because it is there in the drop-down list, doesn't necessarily mean that it is a valid search index.
Here's a list of search indices for US: http://docs.aws.amazon.com/AWSECommerceService/latest/DG/USSearchIndexParamForItemsearch.html . I don't know how up to date it is, but "Amazon Instant Video" does not appear on the list. The error message does include a list of valid search index values, and these do appear to correspond to the above list.
For other locales look here : http://docs.aws.amazon.com/AWSECommerceService/latest/DG/APPNDX_SearchIndexParamForItemsearch.html
I don't think that this is a coding problem per se.
You might like to take a look at python-amazon-product-api. The API might be useful to you, and the documentation might give you some ideas.

Java MongoDB getting value for sub document

I am trying to get the value of a key from a sub-document and I can't seem to figure out how to use the BasicDBObject.get() function since the key is embedded two levels deep. Here is the structure of the document
File {
name: file_1
report: {
name: report_1,
group: RnD
}
}
Basically a file has multiple reports and I need to retrieve the names of all reports in a given file. I am able to do BasicDBObject.get("name") and I can get the value "file_1", but how do I do something like this BasicDBObject.get("report.name")? I tried that but it did not work.

You should first get the "report" object and then access its contents.You can see the sample code in the below.
DBCursor cur = coll.find();
for (DBObject doc : cur) {
String fileName = (String) doc.get("name");
System.out.println(fileName);
DBObject report = (BasicDBObject) doc.get("report");
String reportName = (String) report.get("name");
System.out.println(reportName);
}

I found a second way of doing it, on another post (didnt save the link otherwise I would have included that).
(BasicDBObject)(query.get("report")).getString("name")
where query = (BasicDBObject) cursor.next()

You can also use queries, as in the case of MongoTemplate and so on...
Query query = new Query(Criteria.where("report.name").is("some value"));

You can try this, this worked for me
BasicDBObject query = new BasicDBObject("report.name", "some value");

Lucene : Changing the default facet delimiter?

First post on this wonderful site!
My goal is to use hierarchical facets for searching an index using Lucene. However, my facets need to be delimited by a character other than '/', (in this case, '~'). Example:
Categories
Categories~Category1
Categories~Category2
I have created a class that implements FacetIndexingParams interface (a copy of DefaultFacetIndexingParams with the DEFAULT_FACET_DELIM_CHAR param set to '~').
Paraphrased indexing code : (using FSDirectory for both index and taxonomy)
StandardAnalyzer analyzer = new StandardAnalyzer(Version.LUCENE_34)
IndexWriterConfig config = new IndexWriterConfig(Version.LUCENE_34, analyzer)
IndexWriter writer = new IndexWriter(indexDir, config)
TaxonomyWriter taxo = new LuceneTaxonomyWriter(taxDir, OpenMode.CREATE)
Document doc = new Document()
// Add bunch of Fields... hidden for the sake of brevity
List<CategoryPath> categories = new ArrayList<CategoryPath>()
row.tags.split('\\|').each{ tag ->
def cp = new CategoryPath()
tag.split('~').each{
cp.add(it)
}
categories.add(cp)
}
NewFacetIndexingParams facetIndexingParams = new NewFacetIndexingParams()
DocumentBuilder categoryDocBuilder = new CategoryDocumentBuilder(taxo, facetIndexingParams)
categoryDocBuilder.setCategoryPaths(categories).build(doc)
writer.addDocument(doc)
// Commit and close both writer and taxo.
Search code paraphrased:
// Create index and taxonomoy readers to get info from index and taxonomy
IndexReader indexReader = IndexReader.open(indexDir)
TaxonomyReader taxo = new LuceneTaxonomyReader(taxDir)
Searcher searcher = new IndexSearcher(indexReader)
QueryParser parser = new QueryParser(Version.LUCENE_34, "content", new StandardAnalyzer(Version.LUCENE_34))
parser.setAllowLeadingWildcard(true)
Query q = parser.parse(query)
TopScoreDocCollector tdc = TopScoreDocCollector.create(10, true)
List<FacetResult> res = null
NewFacetIndexingParams facetIndexingParams = new NewFacetIndexingParams()
FacetSearchParams facetSearchParams = new FacetSearchParams(facetIndexingParams)
CountFacetRequest cfr = new CountFacetRequest(new CategoryPath(""), 99)
cfr.setDepth(2)
cfr.setSortBy(SortBy.VALUE)
facetSearchParams.addFacetRequest(cfr)
FacetsCollector facetsCollector = new FacetsCollector(facetSearchParams, indexReader, taxo)
def cp = new CategoryPath("Category~Category1", (char)'~')
searcher.search(DrillDown.query(q, cp), MultiCollector.wrap(tdc, facetsCollector))
The results always return a list of facets in the form of "Category/Category1".
I have used the Luke tool to look at the index and it appears the facets are being delimited by the '~' character in the index.
What is the best route to do this? Any help is greatly appreciated!

I have figured out the issue. The search and indexing are working as they are supposed to. It is how I have been getting the facet results that is the issue. I was using :
res = facetsCollector.getFacetResults()
res.each{ result ->
result.getFacetResultNode().getLabel().toString()
}
What I needed to use was :
res = facetsCollector.getFacetResults()
res.each{ result ->
result.getFacetResultNode().getLabel().toString((char)'~')
}
The difference being the paramter sent to the toString function!
Easy to overlook, tough to find.
Hope this helps others.