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how to multily two fields from two different collections

I have two colections in mongodb sring boot:
public class StampOperation {
#Id
private String id;
private int addedQuantity;
private int previousQuantity;
private int remainingQuantity;
#JsonFormat(pattern="dd/MM/yyyy")
private Date operationDate;
#DBRef
private TaxStamp taxStamp;
}
public class TaxStamp
{
#Id
private String id;
private String name;
private double value;
private EType stampType;
private int globalInitialQuantity;
private int minimumThreshold;
}
is there any wa to multiply addedQuantity from StampOperation by value from TaxStamp ?

If I understand your question correctly, you want to know, how to multiply two values from two different objects.
double result = stampOperation.addedQuantity * taxStamp.value;
To do this operation, you need to have the referenced instances of both classes at hand. Also, the attributes which are supposed to be used (addedQuantity and value) need to be accessible. This could be done by e.g. marking them as public.

How to Convert MongoDB Query to Spring Data Query

I'm trying to convert the following Mongo query for use with Spring data.
db.product.aggregate([
{$unwind: '$barcodes'},
{$project: {
_id: 0,
productId: '$_id',
productTitle: '$title',
productVariation: '$variation',
barcode: '$barcodes'
}}])
This is what I've been trying so far. It returns the aggregation, but with null values:
UnwindOperation unwindOperation = Aggregation.unwind("barcodes");
ProjectionOperation projectStage = Aggregation.project().and("productId").as("_id").and("productTitle")
.as("title")
.and("productVariation").as("variation")
.and("barcodeTitle").as("barcodes.title")
.and("barcodeValue").as("barcodes.value")
.and("barcodeType").as("barcodes.type")
.and("codeStandard").as("barcodes.codeStandard")
.and("quantity").as("barcodes.quantity")
.and("status").as("barcodes.status");
SortOperation sortOperation = Aggregation.sort(Sort.by(Sort.Direction.DESC, "title"));
Aggregation agg = Aggregation.newAggregation(unwindOperation, projectStage, sortOperation);
AggregationResults<BarcodeAggregateList> results = mongoTemplate.aggregate(agg, "product", BarcodeAggregateList.class);
What it is returning:
The class I am mapping to (has getters/setters):
public class BarcodeAggregateList {
private String productId;
private String productTitle;
private String productVariation;
private String barcodeTitle;
private String barcodeValue;
private String barcodeType;
private String codeStandard;
private int quantity;
private String status;
}
Product class that the data is coming from:
public class Product implements Serializable {
private static final long serialVersionUID = -998149317494604215L;
private String id;
private String title;
private String description;
private String SKU;
private double cost;
private double retailPrice;
private String status;
private LocalDate launchDate;
private LocalDate discontinueDate;
private String discontinueReason;
private String salesChannel;
private List<Barcode> barcodes;
private ProductVariation variation;
private List<Supplier> supplier;
private Product parentProduct;
private boolean updateChildren;
private Label label;
private int secondaryStockLevel;
private int primaryStockLevel;
private Date createdDate;
private Date modifiedDate;
private List<Dimension> dimensions;
private boolean isDeleted = false;
}
Barcode class
public class Barcode {
private String type;
private String title;
private String value;
private String status;
private String codeStandard;
private int quantity;
}
I appreciate any help with this or resources to help me better understand how to perform these types of conversions.
For anyone trying to solve similar issues, I've found the following resources somewhat helpful:
https://docs.spring.io/spring-data/mongodb/docs/current/reference/html/#mongo.query
https://xpadro.com/2016/04/data-aggregation-with-spring-data-mongodb-and-spring-boot.html
https://www.tutorialspoint.com/get-fields-from-multiple-sub-documents-that-match-a-condition-in-mongodb

BarcodeAggregateList class fields are null because there is a minor issue in ProjectionOperation's and() and as() methods. The correct syntax is
Aggregation.project().and(SOURCE_FIELD).as(TARGET_FIELD)
You have written and("productId").as("_id") , which is wrong
You need to write this as and("_id").as("productId") , because source field is _id
complete code:
UnwindOperation unwindOperation = Aggregation.unwind("barcodes");
ProjectionOperation projectStage = Aggregation.project()
.and("_id").as("productId")
.and("title").as("productTitle")
.and("variation").as("productVariation")
.and("barcodes.title").as("barcodeTitle")
.and("barcodes.value").as("barcodeValue")
.and("barcodes.type").as("barcodeType")
.and("barcodes.codeStandard").as("codeStandard")
.and("barcodes.quantity").as("quantity")
.and("barcodes.status").as("status");
SortOperation sortOperation = Aggregation.sort(Sort.by(Sort.Direction.DESC, "productTitle"));
Aggregation agg = Aggregation.newAggregation(unwindOperation, projectStage, sortOperation);
AggregationResults<BarcodeAggregateList> results = mongoTemplate.aggregate(agg, "product", BarcodeAggregateList.class);

How to combine data from two reactive streams in project reactor?

I started using Project Reactor recently and I can't work out how to work with nested streams. I want to update data of outer Mono with some data of inner Mono.
#GetMapping("/search")
public Mono<Github> combineGithubData() {
WebClient client = WebClient.create("https://api.github.com");
Mono<Github> data = client.get().uri(URI.create("https://api.github.com/users/autocorrectoff")).retrieve().bodyToMono(Github.class);
data = data.map(s -> {
client.get().uri(URI.create("https://api.github.com/users/Kukilej")).retrieve().bodyToMono(Github.class).map(m -> {
s.setXXX(m.getName());
return m;
});
return s;
});
return data;
}
The field XXX is always returned as null, although I have set it to a value from inner Mono. I'm pretty sure this would work in RxJs. How do I make this work with Project Reactor?
edit:
the code of the Github class
import lombok.*;
#Getter #Setter
#Builder
#ToString
#NoArgsConstructor
#AllArgsConstructor
public class Github {
private String login;
private int id;
private String node_id;
private String avatar_url;
private String gravatar_id;
private String url;
private String html_url;
private String followers_url;
private String following_url;
private String gists_url;
private String starred_url;
private String subscriptions_url;
private String organizations_url;
private String repos_url;
private String events_url;
private String received_events_url;
private String type;
private boolean site_admin;
private String name;
private String company;
private String blog;
private String location;
private String email;
private String hireable;
private String bio;
private int public_repos;
private int public_gists;
private int followers;
private int following;
private String created_at;
private String updated_at;
private String XXX;
}

Your inner stream is not getting subscribed to. Either us flatMap, or better yet, use zip:
data
.zipWith(client.get().uri(...).retrieve().bodyToMono(Github.class))
.map(tuple2 -> {
//update tuple2.getT1() with m.getName() and return the updated tuple
return tuple2.mapT1(tuple2.getT1().setXXX(tuple2.getT2().getName()));
})
.map(tuple2 -> tuple2.getT1() //updated s);
zipWith() subscribes to the inner stream.

how can i combine 3 List of different object into one new object with Java 8

I have 3 objects List and i would like to combine it base on they unique key into one object List.
Since Loan depend on Account and Account depend on Bank
is there simple way without multiple looping for each object in java 8?
I know its better to do it in single query but wonder if there is something existing with Java 8 using List and combine it into one list.
public class Bank {
private String institution; //pk
private String transit; //pk
private String bankName;
}
public class Account {
private String institution; //pk
private String transit; //pk
private String accountNo; //pk
private String nameAccount;
}
public class Loan {
private String institution;//pk
private String transit;//pk
private String accountNo;//pk
private String serviceNo;//pk
}
// fusion object
public class CombineObject {
private String institution;
private String transit;
private String accountNo;
private String serviceNo;
private String nameAccount;
private String bankName;
}
List<Bank> lstBank = myListBank();
List<Account> lstAccount = myListAccount();
List<Loan> lstLoan = myListLoan();

How to find all data in DB using Hibernate?

I have following classes
#Entity
#Table(name="prm_user_permission")
public class UserPermission {
#Id
#GeneratedValue(strategy=GenerationType.IDENTITY)
#Column(name="prm_permission_id")
private Integer permissionId;
#Column(name="prm_permission_name")
private String permissionName;
#Column(name="prm_short_description")
private String shortDescription;
#Column(name="prm_description")
private String description;
#Column(name="prm_url")
private String permissionUrl;
#Column(name="prm_control")
private String control;
#Column(name="prm_create_user")
private Integer creatUser;
#Column(name="prm_parent_id")
private Integer parentId;
#Column(name="prm_system_id")
private Integer systemId;
// Getter and Setter
And my code is
public List<UserPermission> findAllBySystemId(int systemId) {
List<UserPermission> userPermission = criteria().setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY)
.add(eq("UserPermission.systemId", systemId).list();
return userPermission;
}
Now i want to get all data from this (UserPermission) table by "systemId".If i pass systemId=1 then it should give all data where the column is '1'.
what is wrong in my code? while running it shows error like
org.hibernate.QueryException: could not resolve property: UserPermission of:
com.kgfsl.collections.core.security.models.UserPermission
Plz anybody help

What do the criteria() method returns?
And, try with systemId directly (eg: remove the UserPermission.)

Try with Restrictions.eq()
public List<UserPermission> findAllBySystemId(int systemId) {
List<UserPermission> userPermission = criteria().setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY)
.add(Restrictions.eq("systemId", systemId)).list();
return userPermission;
}
Assuming that your criteria() method would be,
session.createCriteria(UserPermission.class)