Which of the following keywords can be used to convert an object into a stream?

In this article, the solution of Java: The keyword "this" and Serialization Example will be demonstrated using examples from the programming language.

class XXX implements Serializable {
 ...
}

We were able to figure out how to solve the Java: The keyword "this" and Serialization Example code by looking at a range of other samples.

What is serialization keyword in Java?

In Java, Serialization is used to convert an object into a stream of the byte. The byte stream consists of the data of the instance as well as the type of data stored in that instance. Deserialization performs exactly opposite operation. It converts the byte sequence into original object data.

Which keywords should avoid serialization?

The transient keyword

What is serialization in Java example?

Serialization is a mechanism of converting the state of an object into a byte stream. Deserialization is the reverse process where the byte stream is used to recreate the actual Java object in memory. This mechanism is used to persist the object.07-Oct-2021

Why serialization is used in Java?

Serialization in Java allows us to convert an Object to stream that we can send over the network or save it as file or store in DB for later usage. Deserialization is the process of converting Object stream to actual Java Object to be used in our program.03-Aug-2022

What is serialization purpose?

Serialization enables us to save the state of an object and recreate the object in a new location. Serialization encompasses both the storage of the object and exchange of data.

What is serialization in OOP?

Serialization or marshaling is the process of converting object state into a format that can be transmitted or stored. The serialization changes the object state into series of bits. The object state could be reconstructed later in the opposite process, called deserialization or unmarshalling .

What happens if we don't serialize in Java?

What happens if you try to send non-serialized Object over network? When traversing a graph, an object may be encountered that does not support the Serializable interface. In this case the NotSerializableException will be thrown and will identify the class of the non-serializable object.19-Apr-2016

What Cannot be serialized in Java?

In Java, serialization is a concept using which we can write the state of an object into a byte stream so that we can transfer it over the network (using technologies like JPA and RMI). But, static variables belong to class therefore, you cannot serialize static variables in Java.29-Jun-2020

What are two popular methods of data serialization?

XML , JSON , BSON, YAML , MessagePack, and protobuf are some commonly used data serialization formats.

What are the types of serialization?

Basic and custom serialization Binary and XML serialization can be performed in two ways, basic and custom.17-Nov-2022

I know this question can be misleading, if possible someone may correct it, I am not sure how to ask a question with this situation.

I am trying to Convert Class X into Class Y (here class Y contains fields of class X, but in different way, Eg:- Integer a, b; inside class X , converts to Map in class Y while other variables stay the same.),

using streams in java 8. I am trying to return the final object to the UI part as json. The project is done in spring boot. Both Class X and Y contains the same objects, but Class Y is to make class X distinct I am not familiar with streams.

Class X

public class X {

private final String thumbnailUrl;
private final Integer duration;
private final String contentId;
private final Date reportDate;
private final Integer count;

public X(Report report, int count) {
    this.thumbnailUrl = report.getContent().getThumbnailUrl();
    this.duration = report.getContent().getDuration();
    this.contentId = report.getContent().getContentId();
    this.reportDate = report.getReportDate();
    this.count = count;
}

public String getThumbnailUrl() {
    return thumbnailUrl;
}

public Integer getDuration() {
    return duration;
}

public String getContentId() {
    return contentId;
}

public Date getReportDate() {
    return reportDate;
}

public Integer getCount() {
    return count;
}    

}

Class Y

public class Y {

private final String thumbnailUrl;
private final Integer duration;
private final String contentId;
private final Map contentList;

public Y(X x, Map contentList) {
    this.thumbnailUrl = x.getThumbnailUrl();
    this.duration = x.getDuration();
    this.contentId = x.getContentId();
    this.contentList = contentList;
}

public String getThumbnailUrl() {
    return thumbnailUrl;
}

public Integer getDuration() {
    return duration;
}

public String getContentId() {
    return contentId;
}

public Map getContentList() {
    return contentList;
}

}

This is what I am currently getting from class X

[
{
    "thumbnailUrl": "a",
    "duration": 12,
    "contentId": "CNT10",
    "reportDate": "2020-01-20",
    "count": 3
},
{
    "thumbnailUrl": "a",
    "duration": 12,
    "contentId": "CNT10",
    "reportDate": "2020-01-21",
    "count": 5
},
{
    "thumbnailUrl": "a",
    "duration": 12,
    "contentId": "CNT10",
    "reportDate": "2020-01-22",
    "count": 3
},
{
    "thumbnailUrl": "a",
    "duration": 12,
    "contentId": "CNT10",
    "reportDate": "2020-01-23",
    "count": 4
}
]

I got the above json in postman after using this code and returning the final list.

List x;
List y;

x = StreamSupport.stream(reportRepository
                .reportWithRoll(a, b, c).spliterator(), false)
                .map(report -> new X(report, report.getStartCount()))
                .collect(Collectors.toList());

I want this to transformed into content of Class Y as below. How can I achieve this with streams in Java?

[
    {
        "list": [
            {
                "2020-01-20": 3,
                "2020-01-21": 5,
                "2020-01-22": 3,
                "2020-01-23": 4
            }
        ],
        "thumbnailUrl": "a",
        "duration": 12,
        "contentId": "CNT10"
    }
]

I tried this to get the above json format, but ended up getting duplicate data, for single contentId and error for multiple contentId

y = x.stream().map(
                rep -> {
                    Map contentList = x.stream().collect(
                            Collectors.toMap(X::getReportDate, X::getCount)
                    );
                    Y yy = new Y(rep, contentList);
                    return yy;
                }
        ).distinct().collect(Collectors.toList());

I am combining the common date and count : key value pair into a single "list" for each unique "contentId" (each unique "contentId" will have its own "thumbnailUrl" and "duration" specific to it, so when I am referring only "contentId" as unique, it will include "thumbnailUrl" and "duration", only the date and count will be multiple for each of these).

Which of the following is a process of converting an object into a stream of bytes deserialization serialization monitoring none of the mentioned options?

What is the technique of converting a native object to a byte stream?

Which of these is a method of ObjectInputStream used to deserialize?

Which of these process is used to extract the state of and object from a stream?