CODEWITHSUNDEEP
serialization
Hossein
Hossein

Reputation: 25944

Why do we use serialization?

Why do we need to use serialization?

If we want to send an object or piece of data through a network we can use streams of bytes. If we want to save some data to the disk, we can again use the binary mode along with the byte streams and save it.

So what's the advantage of using serialization?

Upvotes: 53

Views: 51217

Answers (6)

aderchox
aderchox

Reputation: 4074

In serialization, the point is not turning an object into bits and bytes, objects ARE bits and bytes already. Serialization is the process of making the object's "state" persistent. Notice the word "state", which means the values of the instance variables of the entire object graph (the target object and all the objects it references either directly or indirectly) WITHOUT methods and other extra runtime stuff stuck to them (and of course plus a little more info that JVM needs for restoration of these objects, such as their class types).

So this is the main reason of its necessity: Storing the whole bytes of objects would be expensive, and for all intents and purposes, unnecessary.

Upvotes: 3

aditi Bhatnagar
aditi Bhatnagar

Reputation: 161

Quoting from Designing Data Intensive Applications book:

Programs usually work with data in (at least) two different representations:

  1. In memory, data is kept in objects, structs, lists, arrays, hash tables, trees, and so on. These data structures are optimized for efficient access and manipulation by the CPU (typically using pointers).
  2. When you want to write data to a file or send it over the network, you have to encode it as some kind of self-contained sequence of bytes (for example, a JSON document). Since a pointer wouldn’t make sense to any other process, this sequence-of-bytes representation looks quite different from the data structures that are normally used in memory. Thus, we need some kind of translation between the two representations. The translation from the in-memory representation to a byte sequence is called encoding (also known as serialization or marshalling), and the reverse is called decoding (parsing, deserialization, unmarshalling).

Upvotes: 16

puneeth c
puneeth c

Reputation: 49

Serialization is the process of converting an object into a stream so that it can be saved in any physical file like (XML) or can be saved in Database. The main purpose of Serialization in C# is to persist an object and save it in any specified storage medium like stream, physical file or DataBase.

Upvotes: 4

niconoe
niconoe

Reputation: 772

Technically on the low-level, your serialized object will also end up as a stream of bytes on your cable or your filesystem...

So you can also think of it as a standardized and already available way of converting your objects to a stream of bytes. Storing/transferring object is a very common requirement, and it has less or little meaning to reinvent this wheel in every application.

As other have mentioned, you also know that this object->stream_of_bytes implementation is quite robust, tested, and generally architecture-independent.

This does not mean it is the only acceptable way to save or transfer an object: in some cases, you'll have to implement your own methods, for example to avoid saving unnecessary/private members (for example for security or performance reasons). But if you are in a simple case, you can make your life easier by using the serialization/deserialization of your framework, language or VM instead of having to implement it by yourself.

Hope this helps.

Upvotes: 39

Bgi
Bgi

Reputation: 2494

Among other reasons to be compatible between architecture. An integer doesn't have the same number of bytes from one architecture to another, and sometimes from one compiler to another.

Plus what you're talking about is still serialization. Binary Serialization. You're putting all the bytes of your object together in order to store them and be able to reconvert them as an object later. This is serializing.

More info on wikipedia

Upvotes: 11

ragklaat
ragklaat

Reputation: 946

In General, serialization is a method to persist an object's state, but i suggest you to read this wiki page, it is pretty detailed and correct in my opinion:

http://en.wikipedia.org/wiki/Serialization

Upvotes: 2

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