gaspersic/java-design-patterns
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Update README.md

Browse Source
This commit is contained in:
Ilkka Seppälä 2020-08-29 16:23:28 +03:00
parent 2bb2134636
commit e8b42bd135
1 changed files with 16 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
converter/README.md
View File

@ -9,16 +9,19 @@ tags:
---
## Intent
The purpose of the Converter Pattern is to provide a generic, common way of bidirectional
The purpose of the Converter pattern is to provide a generic, common way of bidirectional
conversion between corresponding types, allowing a clean implementation in which the types do not
need to be aware of each other. Moreover, the Converter Pattern introduces bidirectional collection
need to be aware of each other. Moreover, the Converter pattern introduces bidirectional collection
mapping, reducing a boilerplate code to minimum.
## Explanation
Real world example
> In real world applications it is often the case that database layer consists of entities that need to be mapped into DTOs for use on the business logic layer. Similar mapping is done for potentially huge amount of classes and we need a generic way to achieve this.
> In real world applications it is often the case that database layer consists of entities that need
> to be mapped into DTOs for use on the business logic layer. Similar mapping is done for
> potentially huge amount of classes and we need a generic way to achieve this.
In plain words
@ -26,7 +29,8 @@ In plain words
**Programmatic Example**
We need a generic solution for the mapping problem. To achieve this, let's introduce a generic converter.
We need a generic solution for the mapping problem. To achieve this, let's introduce a generic
converter.
```java
public class Converter<T, U> {
@ -77,7 +81,7 @@ public class UserConverter extends Converter<UserDto, User> {
}
```
Now mapping between User and UserDto becomes trivial.
Now mapping between `User` and `UserDto` becomes trivial.
```java
var userConverter = new UserConverter();
@ -86,14 +90,18 @@ var user = userConverter.convertFromDto(dtoUser);
```
## Class diagram
![alt text](./etc/converter.png "Converter Pattern")
## Applicability
Use the Converter Pattern in the following situations:
* When you have types that logically correspond which other and you need to convert entities between them
* When you want to provide different ways of types conversions depending on a context
* Whenever you introduce a DTO (Data transfer object), you will probably need to convert it into the domain equivalence
* When you have types that logically correspond with each other and you need to convert entities
between them.
* When you want to provide different ways of types conversions depending on the context.
* Whenever you introduce a DTO (Data transfer object), you will probably need to convert it into the
domain equivalence.
## Credits