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getting Duplicate List Values in GET API service in spring Boot

i am getiing proper values from DB but Getting Duplicate List Values while add list object to class object, in Spring Boot
Please suggest to me how to do it.
Get data from DB Code : Here Rooms is my DB Entity class
CriteriaBuilder roomsBuilder = roomSession.getCriteriaBuilder();
CriteriaQuery<Rooms> query = roomsBuilder.createQuery(Rooms.class);
Root<Rooms> root = query.from(Rooms.class);
Predicate userRestriction = roomsBuilder.or(roomsBuilder.notEqual(root.get(SmatrEntityParameters.IS_DELETED), "Y"),
roomsBuilder.isNull(root.get(SmatrEntityParameters.IS_DELETED)));
Predicate userRestriction2 = roomsBuilder.and(roomsBuilder.equal(root.join("properties").get(SmatrEntityParameters.PROPERTY_ID), propertyId));
query.where(roomsBuilder.and(userRestriction, userRestriction2));
Query q = roomSession.createQuery(query);
List<Rooms> getroomslistobj= q.getResultList();
Iterate the list code: Here getAllRoomsobj means main response pojo class
List<GetAllRooms> getallroomslistobj = new ArrayList<GetAllRooms>();
for (int i = 0; i < getroomslistobj.size(); i++) {
int dbroomId = getroomslistobj.get(i).getRoomId();
String dbroomName = getroomslistobj.get(i).getRoomName();
// Actual code start
getAllRoomsobj.setRoomId(dbroomId);
getAllRoomsobj.setRoomName(dbroomName);
getallroomslistobj.add(getAllRoomsobj);
// Actual code end
}
I tried one code at the middle of the Actual code but I did not want create a new object for the response class:
GetAllRooms object = new GetAllRooms();
object.setRoomId(dbroomId);
object.setRoomName(dbroomName);
getallroomslistobj.add(object);
Please Help me Out,
Thanks in Advance

u can try it by stream.map() of java8

OraclePreparedStatementWrapper cannot be cast to java.sql.CallableStatement

I'm trying to call oracle db function by java as following :
StoredProcedureCall getTaxProcedureCall = new StoredProcedureCall();
getTaxProcedureCall.setProcedureName("getTaxByCustomerId");
getTaxProcedureCall.addNamedArgument("ImpactedParty");
getTaxProcedureCall.addNamedArgument("ImpactedPartyType");
getTaxProcedureCall.addNamedOutputArgument("P_TAX");
getTaxProcedureCall.addNamedOutputArgument("A_TAX");
DataReadQuery query = new DataReadQuery();
query.setCall(getTaxProcedureCall);
query.addArgument("ImpactedParty");
query.addArgument("ImpactedPartyType");
Vector queryValues = new Vector();
queryValues.add(cusId);
queryValues.add("CSID");
Vector<DatabaseRecord> records = (Vector<DatabaseRecord>)TransactionContext.getCurrent().getUnitOfWork().executeQuery(query, queryValues);
return records;
but when run it, it gave : oracle.jdbc.driver.OraclePreparedStatementWrapper cannot be cast
to java.sql.CallableStatement
at Vector<DatabaseRecord> records = (Vector<DatabaseRecord>)TransactionContext.getCurrent().getUnitOfWork().executeQuery(query, queryValues);

I have solved the issue by replacing StoredProcedureCall with SQLCall
and pass sql string like:
SELECT getTaxByCustomerId(#ImpactedParty, #ImpactedPartyType, #TaxProfile) AS P_TAX FROM DUAL
now it's work fine.

Using ELKI with Mongodb

Using test cases I was able to see how ELKI can be used directly from Java but now I want to read my data from MongoDB and then use ELKI to cluster geographic (long, lat) data.
I can only cluster data from a CSV file using ELKI. Is it possible to connect de.lmu.ifi.dbs.elki.database.Database with MongoDB? I can see from the java debugger that there is a databaseconnection field in de.lmu.ifi.dbs.elki.database.Database.
I query MongoDB creating POJO for each row and now I want to cluster these objects using ELKI.
It is possible to read data from MongoDB and write it in a CSV file then use ELKI to read that CSV file but I would like to know if there is a simpler solution.
---------FINDINGS_1:
From ELKI - Use List<String> of objects to populate the Database I found that I need to implement de.lmu.ifi.dbs.elki.datasource.DatabaseConnection and specifically override the loadData() method which returns an instance of MultiObjectsBundle.
So I think I should wrap a list of POJO with MultiObjectsBundle. Now i'm looking at the MultiObjectsBundle and it looks like the data should be held in columns. Why columns datatype is List> shouldnt it be List? just a list of items you want to cluster?
I'm a little confused. How is ELKI going to know that it should look at the long and lat for POJO? Where do I tell ELKI to do this? Using de.lmu.ifi.dbs.elki.data.type.SimpleTypeInformation?
---------FINDINGS_2:
I have tried to use ArrayAdapterDatabaseConnection and I have tried implementing DatabaseConnection. Sorry I need thing in very simple terms for me to understand.
This is my code for clustering:
int minPts=3;
double eps=0.08;
double[][] data1 = {{-0.197574246, 51.49960695}, {-0.084605692, 51.52128377}, {-0.120973687, 51.53005939}, {-0.156876, 51.49313},
{-0.144228881, 51.51811784}, {-0.1680743, 51.53430039}, {-0.170134484,51.52834133}, { -0.096440751, 51.5073853},
{-0.092754157, 51.50597426}, {-0.122502346, 51.52395143}, {-0.136039674, 51.51991453}, {-0.123616824, 51.52994371},
{-0.127854211, 51.51772703}, {-0.125979294, 51.52635795}, {-0.109006325, 51.5216612}, {-0.12221963, 51.51477076}, {-0.131161087, 51.52505093} };
// ArrayAdapterDatabaseConnection dbcon = new ArrayAdapterDatabaseConnection(data1);
DatabaseConnection dbcon = new MyDBConnection();
ListParameterization params = new ListParameterization();
params.addParameter(de.lmu.ifi.dbs.elki.algorithm.clustering.DBSCAN.Parameterizer.MINPTS_ID, minPts);
params.addParameter(de.lmu.ifi.dbs.elki.algorithm.clustering.DBSCAN.Parameterizer.EPSILON_ID, eps);
params.addParameter(DBSCAN.DISTANCE_FUNCTION_ID, EuclideanDistanceFunction.class);
params.addParameter(AbstractDatabase.Parameterizer.DATABASE_CONNECTION_ID, dbcon);
params.addParameter(AbstractDatabase.Parameterizer.INDEX_ID,
RStarTreeFactory.class);
params.addParameter(RStarTreeFactory.Parameterizer.BULK_SPLIT_ID,
SortTileRecursiveBulkSplit.class);
params.addParameter(AbstractPageFileFactory.Parameterizer.PAGE_SIZE_ID, 1000);
Database db = ClassGenericsUtil.parameterizeOrAbort(StaticArrayDatabase.class, params);
db.initialize();
GeneralizedDBSCAN dbscan = ClassGenericsUtil.parameterizeOrAbort(GeneralizedDBSCAN.class, params);
Relation<DoubleVector> rel = db.getRelation(TypeUtil.DOUBLE_VECTOR_FIELD);
Relation<ExternalID> relID = db.getRelation(TypeUtil.EXTERNALID);
DBIDRange ids = (DBIDRange) rel.getDBIDs();
Clustering<Model> result = dbscan.run(db);
int i =0;
for(Cluster<Model> clu : result.getAllClusters()) {
System.out.println("#" + i + ": " + clu.getNameAutomatic());
System.out.println("Size: " + clu.size());
System.out.print("Objects: ");
for(DBIDIter it = clu.getIDs().iter(); it.valid(); it.advance()) {
DoubleVector v = rel.get(it);
ExternalID exID = relID.get(it);
System.out.print("DoubleVec: ["+v+"]");
System.out.print("ExID: ["+exID+"]");
final int offset = ids.getOffset(it);
System.out.print(" " + offset);
}
System.out.println();
++i;
}
The ArrayAdapterDatabaseConnection produces two clusters, I just had to play around with the value of epsilon, when I set epsilon=0.008 dbscan started creating clusters. When i set epsilon=0.04 all the items were in 1 cluster.
I have also tried to implement DatabaseConnection:
#Override
public MultipleObjectsBundle loadData() {
MultipleObjectsBundle bundle = new MultipleObjectsBundle();
List<Station> stations = getStations();
List<DoubleVector> vecs = new ArrayList<DoubleVector>();
List<ExternalID> ids = new ArrayList<ExternalID>();
for (Station s : stations){
String strID = Integer.toString(s.getId());
ExternalID i = new ExternalID(strID);
ids.add(i);
double[] st = {s.getLongitude(), s.getLatitude()};
DoubleVector dv = new DoubleVector(st);
vecs.add(dv);
}
SimpleTypeInformation<DoubleVector> type = new VectorFieldTypeInformation<>(DoubleVector.FACTORY, 2, 2, DoubleVector.FACTORY.getDefaultSerializer());
bundle.appendColumn(type, vecs);
bundle.appendColumn(TypeUtil.EXTERNALID, ids);
return bundle;
}
These long/lat are associated with an ID and I need to link them back to this ID to the values. Is the only way to go that using the ID offset (in the code above)? I have tried to add ExternalID column but I don't know how to retrieve the ExternalID for a particular NumberVector?
Also after seeing Using ELKI's Distance Function I tried to use Elki's longLatDistance but it doesn't work and I could not find any examples to implement it.

The interface for data sources is called DatabaseConnection.
JavaDoc of DatabaseConnection
You can implement a MongoDB-based interface to get the data.
It is not complicated interface, it has a single method.

How to get text from app engine datastore?

Can someone please tell me how to get a Text value out of a Google App Engine datastore using Java? I have some entities in the datastore with a Text property named longDescription. When I try this:
DatastoreService ds = DatastoreServiceFactory.getDatastoreService();
Query q = new Query("Items");
PreparedQuery pq = ds.prepare(q);
for (Entity result : pq.asIterable()) {
Text longDescription = (Text)result.getProperty("longDescription");
}
I'm getting this warning on the longDescription assignment line:
WARNING: /pstest
java.lang.ClassCastException: java.lang.String cannot be cast to
com.google.appengine.api.datastore.Text
I'm absolutely bumfuzzled here. The only string in my code is the literal "longDescription" that is used to fetch the correct property. If I put this just above the assignment line:
log.warning("Type is " + (result.getProperty("longDescription")).getClass());
I see the following output:
WARNING: Type is class com.google.appengine.api.datastore.Text
Okay, so result.getProperty("longDescription") really, really is a Text object that is being passed back as an object. I've even tried using the fully qualified name (com.google.appengine.api.datastore.Text) instead of just Text with the same results. Where is the String cast coming in? And more importantly, how do I get that Text out of the datastore? I'm at my wit's end here, and any help would be appreciated!
Oh, one other possibly relevant note: This is the assignment I used when inserting the property into the datastore:
Entity eItem = new Entity("Items");
eItem.setProperty("longDescription", new Text(req.getParameter("ldes")));
ds.put(eItem);
When I look at the description in my management console, it seems to be over 500 characters, and it's displayed like this:
<Text: This is a long form description of an item in the store that is access...>
Did I screw something up when inserting it? If so, how do you insert Text items into the datastore?

I figured out the problem, Wei Hao was right in the comments above. It seems that at some point, I inserted a test String as a longDescription instead of a Text. I'm going to chalk this up to being a lesson learned from the school of hard knocks due to being a bit of a noob with the datastore.
For anyone else who runs across this question, the answer is: If you're iterating over a list of query results, make sure that you're getting back what you expect on every result that comes back! Remember, this isn't an RDBMS and every entity can have a different datatype for the same property. So yes, you can have 1,572,394 entities in which longDescription is a Text and one entity in which longDescription is a String, and this will hose you up.
Here's a little code snippet that probably would help to diagnose this issue:
DatastoreService ds = DatastoreServiceFactory.getDatastoreService();
Query q = new Query("Items");
PreparedQuery pq = ds.prepare(q);
for (Entity result : pq.asIterable()) {
if (longDescription isinstanceof Text)
Text longDescription = (Text)result.getProperty("longDescription");
else
log.severe("Unexpected datatype: longDescription is a "
+ result.getProperty("longDescription").getClass().toString());
}

Here's my code;
DatastoreService ds = DatastoreServiceFactory.getDatastoreService();
Query q = new Query(entityKind);
PreparedQuery pq = ds.prepare(q);
for (Entity e : pq.asIterable()) {
String longtext = ((Text)e.getProperty("somelongdescription")).getValue();}

Google App engine memcached design

I am new to memcache of GAE and I need a help in this.
Basically, I have a datastore which exceeded the Datastore Read Operations limit because of the fact that I didn't use memcache. My datastore has minimal writes but many reads and every time there's a write, it should be available for the read. Since, the site is up and I need a quick resolution for it so I need a design help in this. So the thing is, whenever there's a write in the datastore the new entry should get memcached. One more thing I would like to know that how the datastore can be replicated to the memcache. In parallel, I am working on it but since the site is up I am asking it here without any code in hand.
Thanks
UPDATE:
Java code looks like this:
MemcacheService memcache = MemcacheServiceFactory.getMemcacheService();
if(memcache.contains("LocationInfo"))
{
JSONArray js = new JSONArray((String)memcache.get("LocationInfo"));
result = new ArrayList<LocationInfo>();
for(int i = 0; i < js.length(); i++)
{
JSONObject jso = (JSONObject)js.get(i);
LocationInfo loc = new LocationInfo(jso);
result.add(loc);
}
}
else
{
q1= pm.newQuery(LocationInfo.class);
q1.setFilter(filter);
result = (List<LocationInfo>)q1.execute();
JSONArray js = new JSONArray();
for(LocationInfo loc : result)
{
js.put(loc.toJSON());
}
memcache.put("LocationInfo", js.toString());
}

from google.appengine.ext import db
from google.appengine.api import memcache
def top_arts(update = False):
key = 'top'
#Getting arts from memcache
arts = memcache.get(key)
#Check if key is defined in memcache
#or an update has been invoked
if update or not arts:
#Querying the Google Data store using GQL
arts = db.GqlQuery('SELECT * from Art ORDER BY created DESC LIMIT 10')
memcache.set(key, arts)
return arts
You can use the same function for reading from memcache and then writing data into
memcache
Eg:
for reading from memcache:-
arts = top_arts()
when writing into database:-
#write your entry in database
<some database code>
#update memcache with this new entry
top_arts(update=True)