Compare commits
7 Commits
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all-contri
Author | SHA1 | Date | |
---|---|---|---|
9648d70628 | |||
0c96f4d295 | |||
9ad3aa4240 | |||
4e3ab7d91b | |||
e69408e220 | |||
cfe2854522 | |||
043b0e3f01 |
@ -1296,51 +1296,6 @@
|
||||
"contributions": [
|
||||
"doc"
|
||||
]
|
||||
},
|
||||
{
|
||||
"login": "omk13",
|
||||
"name": "Omar Karazoun",
|
||||
"avatar_url": "https://avatars0.githubusercontent.com/u/59054172?v=4",
|
||||
"profile": "https://github.com/omk13",
|
||||
"contributions": [
|
||||
"code"
|
||||
]
|
||||
},
|
||||
{
|
||||
"login": "jeff303",
|
||||
"name": "Jeff Evans",
|
||||
"avatar_url": "https://avatars0.githubusercontent.com/u/3521562?v=4",
|
||||
"profile": "https://github.com/jeff303",
|
||||
"contributions": [
|
||||
"code"
|
||||
]
|
||||
},
|
||||
{
|
||||
"login": "viveksb007",
|
||||
"name": "Vivek Singh",
|
||||
"avatar_url": "https://avatars1.githubusercontent.com/u/12713808?v=4",
|
||||
"profile": "https://viveksb007.github.io",
|
||||
"contributions": [
|
||||
"code"
|
||||
]
|
||||
},
|
||||
{
|
||||
"login": "siavashsoleymani",
|
||||
"name": "siavash",
|
||||
"avatar_url": "https://avatars2.githubusercontent.com/u/18074419?v=4",
|
||||
"profile": "https://github.com/siavashsoleymani",
|
||||
"contributions": [
|
||||
"code"
|
||||
]
|
||||
},
|
||||
{
|
||||
"login": "ruchpeanuts",
|
||||
"name": "ruchpeanuts",
|
||||
"avatar_url": "https://avatars0.githubusercontent.com/u/29301900?v=4",
|
||||
"profile": "https://github.com/ruchpeanuts",
|
||||
"contributions": [
|
||||
"doc"
|
||||
]
|
||||
}
|
||||
],
|
||||
"contributorsPerLine": 4,
|
||||
|
@ -10,7 +10,7 @@
|
||||
[](https://sonarcloud.io/dashboard?id=iluwatar_java-design-patterns)
|
||||
[](https://gitter.im/iluwatar/java-design-patterns?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
|
||||
<!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
|
||||
[](#contributors-)
|
||||
[](#contributors-)
|
||||
<!-- ALL-CONTRIBUTORS-BADGE:END -->
|
||||
|
||||
# Introduction
|
||||
@ -282,13 +282,6 @@ This project is licensed under the terms of the MIT license.
|
||||
<tr>
|
||||
<td align="center"><a href="https://ibrahimalii.github.io/"><img src="https://avatars2.githubusercontent.com/u/21141301?v=4" width="100px;" alt=""/><br /><sub><b>Ibrahim ali abdelghany</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/pulls?q=is%3Apr+reviewed-by%3AibrahimAlii" title="Reviewed Pull Requests">👀</a></td>
|
||||
<td align="center"><a href="https://github.com/gkulkarni2020"><img src="https://avatars3.githubusercontent.com/u/5161548?v=4" width="100px;" alt=""/><br /><sub><b>Girish Kulkarni</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=gkulkarni2020" title="Documentation">📖</a></td>
|
||||
<td align="center"><a href="https://github.com/omk13"><img src="https://avatars0.githubusercontent.com/u/59054172?v=4" width="100px;" alt=""/><br /><sub><b>Omar Karazoun</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=omk13" title="Code">💻</a></td>
|
||||
<td align="center"><a href="https://github.com/jeff303"><img src="https://avatars0.githubusercontent.com/u/3521562?v=4" width="100px;" alt=""/><br /><sub><b>Jeff Evans</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=jeff303" title="Code">💻</a></td>
|
||||
</tr>
|
||||
<tr>
|
||||
<td align="center"><a href="https://viveksb007.github.io"><img src="https://avatars1.githubusercontent.com/u/12713808?v=4" width="100px;" alt=""/><br /><sub><b>Vivek Singh</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=viveksb007" title="Code">💻</a></td>
|
||||
<td align="center"><a href="https://github.com/siavashsoleymani"><img src="https://avatars2.githubusercontent.com/u/18074419?v=4" width="100px;" alt=""/><br /><sub><b>siavash</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=siavashsoleymani" title="Code">💻</a></td>
|
||||
<td align="center"><a href="https://github.com/ruchpeanuts"><img src="https://avatars0.githubusercontent.com/u/29301900?v=4" width="100px;" alt=""/><br /><sub><b>ruchpeanuts</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=ruchpeanuts" title="Documentation">📖</a></td>
|
||||
</tr>
|
||||
</table>
|
||||
|
||||
|
@ -1,54 +0,0 @@
|
||||
---
|
||||
layout: pattern
|
||||
title: Data Transfer Object
|
||||
folder: data-transfer-object
|
||||
permalink: /patterns/data-transfer-object/
|
||||
categories: Architectural
|
||||
tags:
|
||||
- Performance
|
||||
---
|
||||
|
||||
## Intent
|
||||
|
||||
Pass data with multiple attributes in one shot from client to server, to avoid multiple calls to
|
||||
remote server.
|
||||
|
||||
## Explanation
|
||||
|
||||
Real world example
|
||||
|
||||
> We need to fetch information about customers from remote database. Instead of querying the
|
||||
> attributes one at a time, we use DTOs to transfer all the relevant attributes in a single shot.
|
||||
|
||||
In plain words
|
||||
|
||||
> Using DTO relevant information can be fetched with a single backend query.
|
||||
|
||||
Wikipedia says
|
||||
|
||||
> In the field of programming a data transfer object (DTO) is an object that carries data between
|
||||
> processes. The motivation for its use is that communication between processes is usually done
|
||||
> resorting to remote interfaces (e.g. web services), where each call is an expensive operation.
|
||||
> Because the majority of the cost of each call is related to the round-trip time between the client
|
||||
> and the server, one way of reducing the number of calls is to use an object (the DTO) that
|
||||
> aggregates the data that would have been transferred by the several calls, but that is served by
|
||||
> one call only.
|
||||
|
||||
## Class diagram
|
||||
|
||||

|
||||
|
||||
## Applicability
|
||||
|
||||
Use the Data Transfer Object pattern when:
|
||||
|
||||
* The client is asking for multiple information. And the information is related.
|
||||
* When you want to boost the performance to get resources.
|
||||
* You want reduced number of remote calls.
|
||||
|
||||
## Credits
|
||||
|
||||
* [Design Pattern - Transfer Object Pattern](https://www.tutorialspoint.com/design_pattern/transfer_object_pattern.htm)
|
||||
* [Data Transfer Object](https://msdn.microsoft.com/en-us/library/ff649585.aspx)
|
||||
* [J2EE Design Patterns](https://www.amazon.com/gp/product/0596004273/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0596004273&linkCode=as2&tag=javadesignpat-20&linkId=f27d2644fbe5026ea448791a8ad09c94)
|
||||
* [Patterns of Enterprise Application Architecture](https://www.amazon.com/gp/product/0321127420/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0321127420&linkCode=as2&tag=javadesignpat-20&linkId=014237a67c9d46f384b35e10151956bd)
|
@ -1,129 +0,0 @@
|
||||
@startuml
|
||||
package com.iluwatar.datatransferenum {
|
||||
class App {
|
||||
- LOGGER : Logger {static}
|
||||
+ App()
|
||||
+ main(args : String[]) {static}
|
||||
}
|
||||
class Product {
|
||||
- cost : Double
|
||||
- id : Long
|
||||
- name : String
|
||||
- price : Double
|
||||
- supplier : String
|
||||
+ Product()
|
||||
+ getCost() : Double
|
||||
+ getId() : Long
|
||||
+ getName() : String
|
||||
+ getPrice() : Double
|
||||
+ getSupplier() : String
|
||||
+ setCost(cost : Double) : Product
|
||||
+ setId(id : Long) : Product
|
||||
+ setName(name : String) : Product
|
||||
+ setPrice(price : Double) : Product
|
||||
+ setSupplier(supplier : String) : Product
|
||||
+ toString() : String
|
||||
}
|
||||
enum ProductDTO {
|
||||
+ valueOf(name : String) : ProductDTO {static}
|
||||
+ values() : ProductDTO[] {static}
|
||||
}
|
||||
-interface Cost {
|
||||
+ getCost() : Double {abstract}
|
||||
}
|
||||
-interface Id {
|
||||
+ getId() : Long {abstract}
|
||||
}
|
||||
-interface Name {
|
||||
+ getName() : String {abstract}
|
||||
}
|
||||
-interface Price {
|
||||
+ getPrice() : Double {abstract}
|
||||
}
|
||||
enum Request {
|
||||
+ valueOf(name : String) : Request {static}
|
||||
+ values() : Request[] {static}
|
||||
}
|
||||
class Create {
|
||||
- cost : Double
|
||||
- name : String
|
||||
- price : Double
|
||||
- supplier : String
|
||||
+ Create()
|
||||
+ getCost() : Double
|
||||
+ getName() : String
|
||||
+ getPrice() : Double
|
||||
+ getSupplier() : String
|
||||
+ setCost(cost : Double) : Create
|
||||
+ setName(name : String) : Create
|
||||
+ setPrice(price : Double) : Create
|
||||
+ setSupplier(supplier : String) : Create
|
||||
}
|
||||
enum Response {
|
||||
+ valueOf(name : String) : Response {static}
|
||||
+ values() : Response[] {static}
|
||||
}
|
||||
class Private {
|
||||
- cost : Double
|
||||
- id : Long
|
||||
- name : String
|
||||
- price : Double
|
||||
+ Private()
|
||||
+ getCost() : Double
|
||||
+ getId() : Long
|
||||
+ getName() : String
|
||||
+ getPrice() : Double
|
||||
+ setCost(cost : Double) : Private
|
||||
+ setId(id : Long) : Private
|
||||
+ setName(name : String) : Private
|
||||
+ setPrice(price : Double) : Private
|
||||
+ toString() : String
|
||||
}
|
||||
class Public {
|
||||
- id : Long
|
||||
- name : String
|
||||
- price : Double
|
||||
+ Public()
|
||||
+ getId() : Long
|
||||
+ getName() : String
|
||||
+ getPrice() : Double
|
||||
+ setId(id : Long) : Public
|
||||
+ setName(name : String) : Public
|
||||
+ setPrice(price : Double) : Public
|
||||
+ toString() : String
|
||||
}
|
||||
-interface Supplier {
|
||||
+ getSupplier() : String {abstract}
|
||||
}
|
||||
class ProductResource {
|
||||
- products : List<Product>
|
||||
+ ProductResource(products : List<Product>)
|
||||
+ getAllProductsForAdmin() : List<Private>
|
||||
+ getAllProductsForCustomer() : List<Public>
|
||||
+ getProducts() : List<Product>
|
||||
+ save(createProductDTO : Create)
|
||||
}
|
||||
}
|
||||
Create ..+ Request
|
||||
Request ..+ ProductDTO
|
||||
Private ..+ Response
|
||||
Supplier ..+ ProductDTO
|
||||
Name ..+ ProductDTO
|
||||
ProductResource --> "-products" Product
|
||||
Public ..+ Response
|
||||
Id ..+ ProductDTO
|
||||
Price ..+ ProductDTO
|
||||
Response ..+ ProductDTO
|
||||
Cost ..+ ProductDTO
|
||||
Create ..|> Name
|
||||
Create ..|> Price
|
||||
Create ..|> Cost
|
||||
Create ..|> Supplier
|
||||
Private ..|> Id
|
||||
Private ..|> Name
|
||||
Private ..|> Price
|
||||
Private ..|> Cost
|
||||
Public ..|> Id
|
||||
Public ..|> Name
|
||||
Public ..|> Price
|
||||
@enduml
|
Binary file not shown.
Before Width: | Height: | Size: 120 KiB |
@ -1,61 +0,0 @@
|
||||
<?xml version="1.0" encoding="UTF-8"?>
|
||||
<!--
|
||||
|
||||
The MIT License
|
||||
Copyright © 2014-2019 Ilkka Seppälä
|
||||
|
||||
Permission is hereby granted, free of charge, to any person obtaining a copy
|
||||
of this software and associated documentation files (the "Software"), to deal
|
||||
in the Software without restriction, including without limitation the rights
|
||||
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
||||
copies of the Software, and to permit persons to whom the Software is
|
||||
furnished to do so, subject to the following conditions:
|
||||
|
||||
The above copyright notice and this permission notice shall be included in
|
||||
all copies or substantial portions of the Software.
|
||||
|
||||
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
||||
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
||||
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
||||
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
||||
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
||||
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
||||
THE SOFTWARE.
|
||||
|
||||
-->
|
||||
<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
|
||||
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0">
|
||||
<modelVersion>4.0.0</modelVersion>
|
||||
<parent>
|
||||
<groupId>com.iluwatar</groupId>
|
||||
<artifactId>java-design-patterns</artifactId>
|
||||
<version>1.24.0-SNAPSHOT</version>
|
||||
</parent>
|
||||
<artifactId>data-transfer-object-enum-impl</artifactId>
|
||||
<dependencies>
|
||||
<dependency>
|
||||
<groupId>org.junit.jupiter</groupId>
|
||||
<artifactId>junit-jupiter-engine</artifactId>
|
||||
<scope>test</scope>
|
||||
</dependency>
|
||||
</dependencies>
|
||||
<build>
|
||||
<plugins>
|
||||
<plugin>
|
||||
<groupId>org.apache.maven.plugins</groupId>
|
||||
<artifactId>maven-assembly-plugin</artifactId>
|
||||
<executions>
|
||||
<execution>
|
||||
<configuration>
|
||||
<archive>
|
||||
<manifest>
|
||||
<mainClass>com.iluwatar.datatransferenum.App</mainClass>
|
||||
</manifest>
|
||||
</archive>
|
||||
</configuration>
|
||||
</execution>
|
||||
</executions>
|
||||
</plugin>
|
||||
</plugins>
|
||||
</build>
|
||||
</project>
|
@ -1,59 +0,0 @@
|
||||
package com.iluwatar.datatransferenum;
|
||||
|
||||
import java.util.ArrayList;
|
||||
import java.util.Arrays;
|
||||
import java.util.List;
|
||||
import org.slf4j.Logger;
|
||||
import org.slf4j.LoggerFactory;
|
||||
|
||||
/**
|
||||
* The Data Transfer Object pattern is a design pattern in which an data transfer object is used to
|
||||
* serve related information together to avoid multiple call for each piece of information.
|
||||
*
|
||||
* <p>In this example, ({@link App}) as as product details consumer i.e. client to
|
||||
* request for product details to server.
|
||||
*
|
||||
* <p>productResource ({@link ProductResource}) act as server to serve product information. And
|
||||
* The productDto ({@link ProductDto} is data transfer object to share product information.
|
||||
*/
|
||||
public class App {
|
||||
|
||||
private static final Logger LOGGER = LoggerFactory.getLogger(App.class);
|
||||
|
||||
/**
|
||||
* Method as act client and request to server for details.
|
||||
*
|
||||
* @param args program argument.
|
||||
*/
|
||||
public static void main(String[] args) {
|
||||
Product tv =
|
||||
new Product().setId(1L).setName("TV").setSupplier("Sony").setPrice(1000D).setCost(1090D);
|
||||
Product microwave =
|
||||
new Product().setId(2L).setName("microwave").setSupplier("Delonghi").setPrice(1000D)
|
||||
.setCost(1090D);
|
||||
Product refrigerator =
|
||||
new Product().setId(3L).setName("refrigerator").setSupplier("Botsch").setPrice(1000D)
|
||||
.setCost(1090D);
|
||||
Product airConditioner =
|
||||
new Product().setId(4L).setName("airConditioner").setSupplier("LG").setPrice(1000D)
|
||||
.setCost(1090D);
|
||||
List<Product> products =
|
||||
new ArrayList<>(Arrays.asList(tv, microwave, refrigerator, airConditioner));
|
||||
ProductResource productResource = new ProductResource(products);
|
||||
|
||||
LOGGER.info("####### List of products including sensitive data just for admins: \n {}",
|
||||
Arrays.toString(productResource.getAllProductsForAdmin().toArray()));
|
||||
LOGGER.info("####### List of products for customers: \n {}",
|
||||
Arrays.toString(productResource.getAllProductsForCustomer().toArray()));
|
||||
|
||||
LOGGER.info("####### Going to save Sony PS5 ...");
|
||||
ProductDto.Request.Create createProductRequestDto = new ProductDto.Request.Create()
|
||||
.setName("PS5")
|
||||
.setCost(1000D)
|
||||
.setPrice(1220D)
|
||||
.setSupplier("Sony");
|
||||
productResource.save(createProductRequestDto);
|
||||
LOGGER.info("####### List of products after adding PS5: {}",
|
||||
Arrays.toString(productResource.getProducts().toArray()));
|
||||
}
|
||||
}
|
@ -1,91 +0,0 @@
|
||||
package com.iluwatar.datatransferenum;
|
||||
|
||||
/**
|
||||
* {@link Product} is a entity class for product entity. This class act as entity in the demo.
|
||||
*/
|
||||
public final class Product {
|
||||
private Long id;
|
||||
private String name;
|
||||
private Double price;
|
||||
private Double cost;
|
||||
private String supplier;
|
||||
|
||||
/**
|
||||
* Constructor.
|
||||
*
|
||||
* @param id product id
|
||||
* @param name product name
|
||||
* @param price product price
|
||||
* @param cost product cost
|
||||
* @param supplier product supplier
|
||||
*/
|
||||
public Product(Long id, String name, Double price, Double cost, String supplier) {
|
||||
this.id = id;
|
||||
this.name = name;
|
||||
this.price = price;
|
||||
this.cost = cost;
|
||||
this.supplier = supplier;
|
||||
}
|
||||
|
||||
/**
|
||||
* Constructor.
|
||||
*/
|
||||
public Product() {
|
||||
}
|
||||
|
||||
public Long getId() {
|
||||
return id;
|
||||
}
|
||||
|
||||
public Product setId(Long id) {
|
||||
this.id = id;
|
||||
return this;
|
||||
}
|
||||
|
||||
public String getName() {
|
||||
return name;
|
||||
}
|
||||
|
||||
public Product setName(String name) {
|
||||
this.name = name;
|
||||
return this;
|
||||
}
|
||||
|
||||
public Double getPrice() {
|
||||
return price;
|
||||
}
|
||||
|
||||
public Product setPrice(Double price) {
|
||||
this.price = price;
|
||||
return this;
|
||||
}
|
||||
|
||||
public Double getCost() {
|
||||
return cost;
|
||||
}
|
||||
|
||||
public Product setCost(Double cost) {
|
||||
this.cost = cost;
|
||||
return this;
|
||||
}
|
||||
|
||||
public String getSupplier() {
|
||||
return supplier;
|
||||
}
|
||||
|
||||
public Product setSupplier(String supplier) {
|
||||
this.supplier = supplier;
|
||||
return this;
|
||||
}
|
||||
|
||||
@Override
|
||||
public String toString() {
|
||||
return "Product{"
|
||||
+ "id=" + id
|
||||
+ ", name='" + name + '\''
|
||||
+ ", price=" + price
|
||||
+ ", cost=" + cost
|
||||
+ ", supplier='" + supplier + '\''
|
||||
+ '}';
|
||||
}
|
||||
}
|
@ -1,264 +0,0 @@
|
||||
package com.iluwatar.datatransferenum;
|
||||
|
||||
/**
|
||||
* {@link ProductDto} is a data transfer object POJO.
|
||||
* Instead of sending individual information to
|
||||
* client We can send related information together in POJO.
|
||||
*
|
||||
* <p>Dto will not have any business logic in it.
|
||||
*/
|
||||
public enum ProductDto {
|
||||
;
|
||||
|
||||
/**
|
||||
* This is Request class which consist of Create or any other request DTO's
|
||||
* you might want to use in your API.
|
||||
*/
|
||||
public enum Request {
|
||||
;
|
||||
|
||||
/**
|
||||
* This is Create dto class for requesting create new product.
|
||||
*/
|
||||
public static final class Create implements Name, Price, Cost, Supplier {
|
||||
private String name;
|
||||
private Double price;
|
||||
private Double cost;
|
||||
private String supplier;
|
||||
|
||||
@Override
|
||||
public String getName() {
|
||||
return name;
|
||||
}
|
||||
|
||||
public Create setName(String name) {
|
||||
this.name = name;
|
||||
return this;
|
||||
}
|
||||
|
||||
@Override
|
||||
public Double getPrice() {
|
||||
return price;
|
||||
}
|
||||
|
||||
public Create setPrice(Double price) {
|
||||
this.price = price;
|
||||
return this;
|
||||
}
|
||||
|
||||
@Override
|
||||
public Double getCost() {
|
||||
return cost;
|
||||
}
|
||||
|
||||
public Create setCost(Double cost) {
|
||||
this.cost = cost;
|
||||
return this;
|
||||
}
|
||||
|
||||
@Override
|
||||
public String getSupplier() {
|
||||
return supplier;
|
||||
}
|
||||
|
||||
public Create setSupplier(String supplier) {
|
||||
this.supplier = supplier;
|
||||
return this;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* This is Response class which consist of any response DTO's
|
||||
* you might want to provide to your clients.
|
||||
*/
|
||||
public enum Response {
|
||||
;
|
||||
|
||||
/**
|
||||
* This is Public dto class for API response with the lowest data security.
|
||||
*/
|
||||
public static final class Public implements Id, Name, Price {
|
||||
private Long id;
|
||||
private String name;
|
||||
private Double price;
|
||||
|
||||
@Override
|
||||
public Long getId() {
|
||||
return id;
|
||||
}
|
||||
|
||||
public Public setId(Long id) {
|
||||
this.id = id;
|
||||
return this;
|
||||
}
|
||||
|
||||
@Override
|
||||
public String getName() {
|
||||
return name;
|
||||
}
|
||||
|
||||
public Public setName(String name) {
|
||||
this.name = name;
|
||||
return this;
|
||||
}
|
||||
|
||||
@Override
|
||||
public Double getPrice() {
|
||||
return price;
|
||||
}
|
||||
|
||||
public Public setPrice(Double price) {
|
||||
this.price = price;
|
||||
return this;
|
||||
}
|
||||
|
||||
@Override
|
||||
public String toString() {
|
||||
return "Public{"
|
||||
+ "id="
|
||||
+ id
|
||||
+ ", name='"
|
||||
+ name
|
||||
+ '\''
|
||||
+ ", price="
|
||||
+ price
|
||||
+ '}';
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* This is Private dto class for API response with the highest data security.
|
||||
*/
|
||||
public static final class Private implements Id, Name, Price, Cost {
|
||||
private Long id;
|
||||
private String name;
|
||||
private Double price;
|
||||
private Double cost;
|
||||
|
||||
@Override
|
||||
public Long getId() {
|
||||
return id;
|
||||
}
|
||||
|
||||
public Private setId(Long id) {
|
||||
this.id = id;
|
||||
return this;
|
||||
}
|
||||
|
||||
@Override
|
||||
public String getName() {
|
||||
return name;
|
||||
}
|
||||
|
||||
public Private setName(String name) {
|
||||
this.name = name;
|
||||
return this;
|
||||
}
|
||||
|
||||
@Override
|
||||
public Double getPrice() {
|
||||
return price;
|
||||
}
|
||||
|
||||
public Private setPrice(Double price) {
|
||||
this.price = price;
|
||||
return this;
|
||||
}
|
||||
|
||||
@Override
|
||||
public Double getCost() {
|
||||
return cost;
|
||||
}
|
||||
|
||||
public Private setCost(Double cost) {
|
||||
this.cost = cost;
|
||||
return this;
|
||||
}
|
||||
|
||||
@Override
|
||||
public String toString() {
|
||||
return "Private{"
|
||||
+
|
||||
"id="
|
||||
+ id
|
||||
+
|
||||
", name='"
|
||||
+ name
|
||||
+ '\''
|
||||
+
|
||||
", price="
|
||||
+ price
|
||||
+
|
||||
", cost="
|
||||
+ cost
|
||||
+
|
||||
'}';
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Use this interface whenever you want to provide the product Id in your DTO.
|
||||
*/
|
||||
private interface Id {
|
||||
/**
|
||||
* Unique identifier of the product.
|
||||
*
|
||||
* @return : id of the product.
|
||||
*/
|
||||
Long getId();
|
||||
}
|
||||
|
||||
/**
|
||||
* Use this interface whenever you want to provide the product Name in your DTO.
|
||||
*/
|
||||
private interface Name {
|
||||
/**
|
||||
* The name of the product.
|
||||
*
|
||||
* @return : name of the product.
|
||||
*/
|
||||
String getName();
|
||||
}
|
||||
|
||||
/**
|
||||
* Use this interface whenever you want to provide the product Price in your DTO.
|
||||
*/
|
||||
private interface Price {
|
||||
/**
|
||||
* The amount we sell a product for.
|
||||
* <b>This data is not confidential</b>
|
||||
*
|
||||
* @return : price of the product.
|
||||
*/
|
||||
Double getPrice();
|
||||
}
|
||||
|
||||
/**
|
||||
* Use this interface whenever you want to provide the product Cost in your DTO.
|
||||
*/
|
||||
private interface Cost {
|
||||
/**
|
||||
* The amount that it costs us to purchase this product
|
||||
* For the amount we sell a product for, see the {@link Price Price} parameter.
|
||||
* <b>This data is confidential</b>
|
||||
*
|
||||
* @return : cost of the product.
|
||||
*/
|
||||
Double getCost();
|
||||
}
|
||||
|
||||
/**
|
||||
* Use this interface whenever you want to provide the product Supplier in your DTO.
|
||||
*/
|
||||
private interface Supplier {
|
||||
/**
|
||||
* The name of supplier of the product or its manufacturer.
|
||||
* <b>This data is highly confidential</b>
|
||||
*
|
||||
* @return : supplier of the product.
|
||||
*/
|
||||
String getSupplier();
|
||||
}
|
||||
}
|
@ -1,71 +0,0 @@
|
||||
package com.iluwatar.datatransferenum;
|
||||
|
||||
import java.util.List;
|
||||
import java.util.stream.Collectors;
|
||||
|
||||
/**
|
||||
* The resource class which serves product information. This class act as server in the demo. Which
|
||||
* has all product details.
|
||||
*/
|
||||
public class ProductResource {
|
||||
private final List<Product> products;
|
||||
|
||||
/**
|
||||
* Initialise resource with existing products.
|
||||
*
|
||||
* @param products initialize resource with existing products. Act as database.
|
||||
*/
|
||||
public ProductResource(final List<Product> products) {
|
||||
this.products = products;
|
||||
}
|
||||
|
||||
/**
|
||||
* Get all products.
|
||||
*
|
||||
* @return : all products in list but in the scheme of private dto.
|
||||
*/
|
||||
public List<ProductDto.Response.Private> getAllProductsForAdmin() {
|
||||
return products
|
||||
.stream()
|
||||
.map(p -> new ProductDto.Response.Private().setId(p.getId()).setName(p.getName())
|
||||
.setCost(p.getCost())
|
||||
.setPrice(p.getPrice()))
|
||||
.collect(Collectors.toList());
|
||||
}
|
||||
|
||||
/**
|
||||
* Get all products.
|
||||
*
|
||||
* @return : all products in list but in the scheme of public dto.
|
||||
*/
|
||||
public List<ProductDto.Response.Public> getAllProductsForCustomer() {
|
||||
return products
|
||||
.stream()
|
||||
.map(p -> new ProductDto.Response.Public().setId(p.getId()).setName(p.getName())
|
||||
.setPrice(p.getPrice()))
|
||||
.collect(Collectors.toList());
|
||||
}
|
||||
|
||||
/**
|
||||
* Save new product.
|
||||
*
|
||||
* @param createProductDto save new product to list.
|
||||
*/
|
||||
public void save(ProductDto.Request.Create createProductDto) {
|
||||
products.add(new Product()
|
||||
.setId((long) (products.size() + 1))
|
||||
.setName(createProductDto.getName())
|
||||
.setSupplier(createProductDto.getSupplier())
|
||||
.setPrice(createProductDto.getPrice())
|
||||
.setCost(createProductDto.getCost()));
|
||||
}
|
||||
|
||||
/**
|
||||
* List of all products in an entity representation.
|
||||
*
|
||||
* @return : all the products entity that stored in the products list
|
||||
*/
|
||||
public List<Product> getProducts() {
|
||||
return products;
|
||||
}
|
||||
}
|
@ -1,44 +0,0 @@
|
||||
/*
|
||||
* The MIT License
|
||||
* Copyright © 2014-2019 Ilkka Seppälä
|
||||
*
|
||||
* Permission is hereby granted, free of charge, to any person obtaining a copy
|
||||
* of this software and associated documentation files (the "Software"), to deal
|
||||
* in the Software without restriction, including without limitation the rights
|
||||
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
||||
* copies of the Software, and to permit persons to whom the Software is
|
||||
* furnished to do so, subject to the following conditions:
|
||||
*
|
||||
* The above copyright notice and this permission notice shall be included in
|
||||
* all copies or substantial portions of the Software.
|
||||
*
|
||||
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
||||
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
||||
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
||||
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
||||
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
||||
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
||||
* THE SOFTWARE.
|
||||
*/
|
||||
|
||||
package com.iluwatar.datatransferenum;
|
||||
|
||||
import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
|
||||
|
||||
|
||||
import org.junit.jupiter.api.Test;
|
||||
|
||||
class AppTest {
|
||||
|
||||
/**
|
||||
* Issue: Add at least one assertion to this test case.
|
||||
* <p>
|
||||
* Solution: Inserted assertion to check whether the execution of the main method in {@link App#main(String[])}
|
||||
* throws an exception.
|
||||
*/
|
||||
|
||||
@Test
|
||||
void shouldExecuteApplicationWithoutException() {
|
||||
assertDoesNotThrow(() -> App.main(new String[] {}));
|
||||
}
|
||||
}
|
@ -98,7 +98,7 @@ Now on the client code we can create different types of cars using the factory c
|
||||
var car1 = CarsFactory.getCar(CarType.FORD);
|
||||
var car2 = CarsFactory.getCar(CarType.FERRARI);
|
||||
LOGGER.info(car1.getDescription());
|
||||
LOGGER.info(car2.getDescription());
|
||||
LOGGER.info(car2.getDescription());;
|
||||
```
|
||||
|
||||
Program output:
|
||||
@ -126,16 +126,6 @@ Cons
|
||||
|
||||
* The code becomes more complicated than it should be.
|
||||
|
||||
## Real world examples
|
||||
|
||||
* [java.util.Calendar#getInstance()](https://docs.oracle.com/javase/8/docs/api/java/util/Calendar.html#getInstance--)
|
||||
* [java.util.ResourceBundle#getBundle()](https://docs.oracle.com/javase/8/docs/api/java/util/ResourceBundle.html#getBundle-java.lang.String-)
|
||||
* [java.text.NumberFormat#getInstance()](https://docs.oracle.com/javase/8/docs/api/java/text/NumberFormat.html#getInstance--)
|
||||
* [java.nio.charset.Charset#forName()](https://docs.oracle.com/javase/8/docs/api/java/nio/charset/Charset.html#forName-java.lang.String-)
|
||||
* [java.net.URLStreamHandlerFactory#createURLStreamHandler(String)](https://docs.oracle.com/javase/8/docs/api/java/net/URLStreamHandlerFactory.html) (Returns different singleton objects, depending on a protocol)
|
||||
* [java.util.EnumSet#of()](https://docs.oracle.com/javase/8/docs/api/java/util/EnumSet.html#of(E))
|
||||
* [javax.xml.bind.JAXBContext#createMarshaller()](https://docs.oracle.com/javase/8/docs/api/javax/xml/bind/JAXBContext.html#createMarshaller--) and other similar methods.
|
||||
|
||||
## Related patterns
|
||||
|
||||
* [Factory Method](https://java-design-patterns.com/patterns/factory-method/)
|
||||
|
@ -23,7 +23,7 @@
|
||||
|
||||
package com.iluwatar.gameloop;
|
||||
|
||||
import org.junit.jupiter.api.Test;
|
||||
import org.junit.Test;
|
||||
|
||||
import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
|
||||
|
||||
|
@ -23,11 +23,10 @@
|
||||
|
||||
package com.iluwatar.gameloop;
|
||||
|
||||
import static org.junit.jupiter.api.Assertions.assertEquals;
|
||||
|
||||
import org.junit.jupiter.api.Test;
|
||||
import org.junit.jupiter.api.AfterEach;
|
||||
import org.junit.jupiter.api.BeforeEach;
|
||||
import org.junit.After;
|
||||
import org.junit.Assert;
|
||||
import org.junit.Before;
|
||||
import org.junit.Test;
|
||||
|
||||
/**
|
||||
* FixedStepGameLoop unit test class.
|
||||
@ -36,12 +35,12 @@ public class FixedStepGameLoopTest {
|
||||
|
||||
private FixedStepGameLoop gameLoop;
|
||||
|
||||
@BeforeEach
|
||||
@Before
|
||||
public void setup() {
|
||||
gameLoop = new FixedStepGameLoop();
|
||||
}
|
||||
|
||||
@AfterEach
|
||||
@After
|
||||
public void tearDown() {
|
||||
gameLoop = null;
|
||||
}
|
||||
@ -49,7 +48,7 @@ public class FixedStepGameLoopTest {
|
||||
@Test
|
||||
public void testUpdate() {
|
||||
gameLoop.update();
|
||||
assertEquals(0.01f, gameLoop.controller.getBulletPosition(), 0);
|
||||
Assert.assertEquals(0.01f, gameLoop.controller.getBulletPosition(), 0);
|
||||
}
|
||||
|
||||
}
|
||||
|
@ -23,10 +23,10 @@
|
||||
|
||||
package com.iluwatar.gameloop;
|
||||
|
||||
import static org.junit.jupiter.api.Assertions.assertEquals;
|
||||
|
||||
import org.junit.jupiter.api.AfterEach;
|
||||
import org.junit.jupiter.api.BeforeEach;
|
||||
import org.junit.After;
|
||||
import org.junit.Assert;
|
||||
import org.junit.Before;
|
||||
import org.junit.Test;
|
||||
|
||||
/**
|
||||
* FrameBasedGameLoop unit test class.
|
||||
@ -35,19 +35,19 @@ public class FrameBasedGameLoopTest {
|
||||
|
||||
private FrameBasedGameLoop gameLoop;
|
||||
|
||||
@BeforeEach
|
||||
@Before
|
||||
public void setup() {
|
||||
gameLoop = new FrameBasedGameLoop();
|
||||
}
|
||||
|
||||
@AfterEach
|
||||
@After
|
||||
public void tearDown() {
|
||||
gameLoop = null;
|
||||
}
|
||||
|
||||
@org.junit.jupiter.api.Test
|
||||
@Test
|
||||
public void testUpdate() {
|
||||
gameLoop.update();
|
||||
assertEquals(0.5f, gameLoop.controller.getBulletPosition(), 0);
|
||||
Assert.assertEquals(0.5f, gameLoop.controller.getBulletPosition(), 0);
|
||||
}
|
||||
}
|
||||
|
@ -23,33 +23,34 @@
|
||||
|
||||
package com.iluwatar.gameloop;
|
||||
|
||||
import org.junit.jupiter.api.Assertions;
|
||||
import org.junit.jupiter.api.AfterEach;
|
||||
import org.junit.jupiter.api.BeforeEach;
|
||||
import org.junit.After;
|
||||
import org.junit.Assert;
|
||||
import org.junit.Before;
|
||||
import org.junit.Test;
|
||||
|
||||
public class GameControllerTest {
|
||||
|
||||
private GameController controller;
|
||||
|
||||
@BeforeEach
|
||||
@Before
|
||||
public void setup() {
|
||||
controller = new GameController();
|
||||
}
|
||||
|
||||
@AfterEach
|
||||
@After
|
||||
public void tearDown() {
|
||||
controller = null;
|
||||
}
|
||||
|
||||
@org.junit.jupiter.api.Test
|
||||
@Test
|
||||
public void testMoveBullet() {
|
||||
controller.moveBullet(1.5f);
|
||||
Assertions.assertEquals(1.5f, controller.bullet.getPosition(), 0);
|
||||
Assert.assertEquals(1.5f, controller.bullet.getPosition(), 0);
|
||||
}
|
||||
|
||||
@org.junit.jupiter.api.Test
|
||||
@Test
|
||||
public void testGetBulletPosition() {
|
||||
Assertions.assertEquals(controller.bullet.getPosition(), controller.getBulletPosition(), 0);
|
||||
Assert.assertEquals(controller.bullet.getPosition(), controller.getBulletPosition(), 0);
|
||||
}
|
||||
|
||||
}
|
||||
|
@ -23,9 +23,10 @@
|
||||
|
||||
package com.iluwatar.gameloop;
|
||||
|
||||
import org.junit.jupiter.api.AfterEach;
|
||||
import org.junit.jupiter.api.Assertions;
|
||||
import org.junit.jupiter.api.BeforeEach;
|
||||
import org.junit.After;
|
||||
import org.junit.Assert;
|
||||
import org.junit.Before;
|
||||
import org.junit.Test;
|
||||
|
||||
/**
|
||||
* GameLoop unit test class.
|
||||
@ -37,7 +38,7 @@ public class GameLoopTest {
|
||||
/**
|
||||
* Create mock implementation of GameLoop.
|
||||
*/
|
||||
@BeforeEach
|
||||
@Before
|
||||
public void setup() {
|
||||
gameLoop = new GameLoop() {
|
||||
@Override
|
||||
@ -45,26 +46,26 @@ public class GameLoopTest {
|
||||
};
|
||||
}
|
||||
|
||||
@AfterEach
|
||||
@After
|
||||
public void tearDown() {
|
||||
gameLoop = null;
|
||||
}
|
||||
|
||||
@org.junit.jupiter.api.Test
|
||||
@Test
|
||||
public void testRun() {
|
||||
gameLoop.run();
|
||||
Assertions.assertEquals(GameStatus.RUNNING, gameLoop.status);
|
||||
Assert.assertEquals(GameStatus.RUNNING, gameLoop.status);
|
||||
}
|
||||
|
||||
@org.junit.jupiter.api.Test
|
||||
@Test
|
||||
public void testStop() {
|
||||
gameLoop.stop();
|
||||
Assertions.assertEquals(GameStatus.STOPPED, gameLoop.status);
|
||||
Assert.assertEquals(GameStatus.STOPPED, gameLoop.status);
|
||||
}
|
||||
|
||||
@org.junit.jupiter.api.Test
|
||||
@Test
|
||||
public void testIsGameRunning() {
|
||||
Assertions.assertFalse(gameLoop.isGameRunning());
|
||||
Assert.assertFalse(gameLoop.isGameRunning());
|
||||
}
|
||||
|
||||
}
|
||||
|
@ -23,9 +23,11 @@
|
||||
|
||||
package com.iluwatar.gameloop;
|
||||
|
||||
import org.junit.jupiter.api.Assertions;
|
||||
import org.junit.jupiter.api.AfterEach;
|
||||
import org.junit.jupiter.api.BeforeEach;
|
||||
import java.lang.reflect.InvocationTargetException;
|
||||
import org.junit.After;
|
||||
import org.junit.Assert;
|
||||
import org.junit.Before;
|
||||
import org.junit.Test;
|
||||
|
||||
/**
|
||||
* VariableStepGameLoop unit test class.
|
||||
@ -34,19 +36,19 @@ public class VariableStepGameLoopTest {
|
||||
|
||||
private VariableStepGameLoop gameLoop;
|
||||
|
||||
@BeforeEach
|
||||
@Before
|
||||
public void setup() {
|
||||
gameLoop = new VariableStepGameLoop();
|
||||
}
|
||||
|
||||
@AfterEach
|
||||
@After
|
||||
public void tearDown() {
|
||||
gameLoop = null;
|
||||
}
|
||||
|
||||
@org.junit.jupiter.api.Test
|
||||
@Test
|
||||
public void testUpdate() {
|
||||
gameLoop.update(20L);
|
||||
Assertions.assertEquals(0.01f, gameLoop.controller.getBulletPosition(), 0);
|
||||
Assert.assertEquals(0.01f, gameLoop.controller.getBulletPosition(), 0);
|
||||
}
|
||||
}
|
||||
|
2
pom.xml
2
pom.xml
@ -195,11 +195,9 @@
|
||||
<module>strangler</module>
|
||||
<module>arrange-act-assert</module>
|
||||
<module>transaction-script</module>
|
||||
<module>registry</module>
|
||||
<module>filterer</module>
|
||||
<module>factory</module>
|
||||
<module>separated-interface</module>
|
||||
<module>data-transfer-object-enum-impl</module>
|
||||
</modules>
|
||||
|
||||
<repositories>
|
||||
|
@ -1,86 +0,0 @@
|
||||
---
|
||||
layout: pattern
|
||||
title: Registry
|
||||
folder: registry
|
||||
permalink: /patterns/registry/
|
||||
categories: Creational
|
||||
tags:
|
||||
- Instantiation
|
||||
---
|
||||
|
||||
## Intent
|
||||
Stores the objects of a single class and provide a global point of access to them.
|
||||
Similar to Multiton pattern, only difference is that in a registry there is no restriction on the number of objects.
|
||||
|
||||
## Explanation
|
||||
|
||||
In Plain Words
|
||||
|
||||
> Registry is a well-known object that other objects can use to find common objects and services.
|
||||
|
||||
**Programmatic Example**
|
||||
Below is a `Customer` Class
|
||||
|
||||
```java
|
||||
public class Customer {
|
||||
|
||||
private final String id;
|
||||
private final String name;
|
||||
|
||||
public Customer(String id, String name) {
|
||||
this.id = id;
|
||||
this.name = name;
|
||||
}
|
||||
|
||||
public String getId() {
|
||||
return id;
|
||||
}
|
||||
|
||||
public String getName() {
|
||||
return name;
|
||||
}
|
||||
|
||||
}
|
||||
```
|
||||
|
||||
This registry of the `Customer` objects is `CustomerRegistry`
|
||||
```java
|
||||
public final class CustomerRegistry {
|
||||
|
||||
private static final CustomerRegistry instance = new CustomerRegistry();
|
||||
|
||||
public static CustomerRegistry getInstance() {
|
||||
return instance;
|
||||
}
|
||||
|
||||
private final Map<String, Customer> customerMap;
|
||||
|
||||
private CustomerRegistry() {
|
||||
customerMap = new ConcurrentHashMap<>();
|
||||
}
|
||||
|
||||
public Customer addCustomer(Customer customer) {
|
||||
return customerMap.put(customer.getId(), customer);
|
||||
}
|
||||
|
||||
public Customer getCustomer(String id) {
|
||||
return customerMap.get(id);
|
||||
}
|
||||
|
||||
}
|
||||
```
|
||||
|
||||
## Class diagram
|
||||

|
||||
|
||||
## Applicability
|
||||
Use Registry pattern when
|
||||
|
||||
* client wants reference of some object, so client can lookup for that object in the object's registry.
|
||||
|
||||
## Consequences
|
||||
Large number of bulky objects added to registry would result in a lot of memory consumption as objects in the registry are not garbage collected.
|
||||
|
||||
## Credits
|
||||
* https://www.martinfowler.com/eaaCatalog/registry.html
|
||||
* https://wiki.c2.com/?RegistryPattern
|
Binary file not shown.
Before Width: | Height: | Size: 16 KiB |
@ -1,21 +0,0 @@
|
||||
@startuml
|
||||
package com.iluwatar.registry {
|
||||
class App {
|
||||
- LOGGER : Logger {static}
|
||||
+ App()
|
||||
+ main(args : String[]) {static}
|
||||
}
|
||||
class Customer {
|
||||
- id : String
|
||||
- name : String
|
||||
+ getId() : String
|
||||
+ getName() : String
|
||||
+ toString() : String
|
||||
}
|
||||
class CustomerRegistry {
|
||||
+ addCustomer(customer : Customer)
|
||||
+ getCustomer(id : String)
|
||||
}
|
||||
}
|
||||
Customer --> "-addCustomer" CustomerRegistry
|
||||
@enduml
|
@ -1,46 +0,0 @@
|
||||
<?xml version="1.0" encoding="UTF-8"?>
|
||||
<project xmlns="http://maven.apache.org/POM/4.0.0"
|
||||
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
|
||||
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
|
||||
<modelVersion>4.0.0</modelVersion>
|
||||
|
||||
<parent>
|
||||
<groupId>com.iluwatar</groupId>
|
||||
<artifactId>java-design-patterns</artifactId>
|
||||
<version>1.24.0-SNAPSHOT</version>
|
||||
</parent>
|
||||
<artifactId>registry</artifactId>
|
||||
|
||||
<dependencies>
|
||||
<dependency>
|
||||
<groupId>org.junit.jupiter</groupId>
|
||||
<artifactId>junit-jupiter-engine</artifactId>
|
||||
<scope>test</scope>
|
||||
</dependency>
|
||||
<dependency>
|
||||
<groupId>junit</groupId>
|
||||
<artifactId>junit</artifactId>
|
||||
</dependency>
|
||||
</dependencies>
|
||||
|
||||
<build>
|
||||
<plugins>
|
||||
<plugin>
|
||||
<groupId>org.apache.maven.plugins</groupId>
|
||||
<artifactId>maven-assembly-plugin</artifactId>
|
||||
<executions>
|
||||
<execution>
|
||||
<configuration>
|
||||
<archive>
|
||||
<manifest>
|
||||
<mainClass>com.iluwatar.registry.App</mainClass>
|
||||
</manifest>
|
||||
</archive>
|
||||
</configuration>
|
||||
</execution>
|
||||
</executions>
|
||||
</plugin>
|
||||
</plugins>
|
||||
</build>
|
||||
|
||||
</project>
|
@ -1,27 +0,0 @@
|
||||
package com.iluwatar.registry;
|
||||
|
||||
import org.slf4j.Logger;
|
||||
import org.slf4j.LoggerFactory;
|
||||
|
||||
public class App {
|
||||
|
||||
private static final Logger LOGGER = LoggerFactory.getLogger(App.class);
|
||||
|
||||
/**
|
||||
* Program entry point.
|
||||
*
|
||||
* @param args command line args
|
||||
*/
|
||||
public static void main(String[] args) {
|
||||
CustomerRegistry customerRegistry = CustomerRegistry.getInstance();
|
||||
var john = new Customer("1", "John");
|
||||
customerRegistry.addCustomer(john);
|
||||
|
||||
var julia = new Customer("2", "Julia");
|
||||
customerRegistry.addCustomer(julia);
|
||||
|
||||
LOGGER.info("John {}", customerRegistry.getCustomer("1"));
|
||||
LOGGER.info("Julia {}", customerRegistry.getCustomer("2"));
|
||||
}
|
||||
|
||||
}
|
@ -1,28 +0,0 @@
|
||||
package com.iluwatar.registry;
|
||||
|
||||
public class Customer {
|
||||
|
||||
private final String id;
|
||||
private final String name;
|
||||
|
||||
public Customer(String id, String name) {
|
||||
this.id = id;
|
||||
this.name = name;
|
||||
}
|
||||
|
||||
public String getId() {
|
||||
return id;
|
||||
}
|
||||
|
||||
public String getName() {
|
||||
return name;
|
||||
}
|
||||
|
||||
@Override
|
||||
public String toString() {
|
||||
return "Customer{"
|
||||
+ "id='" + id + '\''
|
||||
+ ", name='" + name + '\''
|
||||
+ '}';
|
||||
}
|
||||
}
|
@ -1,28 +0,0 @@
|
||||
package com.iluwatar.registry;
|
||||
|
||||
import java.util.Map;
|
||||
import java.util.concurrent.ConcurrentHashMap;
|
||||
|
||||
public final class CustomerRegistry {
|
||||
|
||||
private static final CustomerRegistry instance = new CustomerRegistry();
|
||||
|
||||
public static CustomerRegistry getInstance() {
|
||||
return instance;
|
||||
}
|
||||
|
||||
private final Map<String, Customer> customerMap;
|
||||
|
||||
private CustomerRegistry() {
|
||||
customerMap = new ConcurrentHashMap<>();
|
||||
}
|
||||
|
||||
public Customer addCustomer(Customer customer) {
|
||||
return customerMap.put(customer.getId(), customer);
|
||||
}
|
||||
|
||||
public Customer getCustomer(String id) {
|
||||
return customerMap.get(id);
|
||||
}
|
||||
|
||||
}
|
@ -1,44 +0,0 @@
|
||||
package com.iluwatar.registry;
|
||||
|
||||
import org.junit.jupiter.api.BeforeAll;
|
||||
import org.junit.jupiter.api.Test;
|
||||
|
||||
import static org.junit.jupiter.api.Assertions.assertEquals;
|
||||
import static org.junit.jupiter.api.Assertions.assertNotNull;
|
||||
import static org.junit.jupiter.api.Assertions.assertNull;
|
||||
|
||||
public class CustomerRegistryTest {
|
||||
|
||||
private static CustomerRegistry customerRegistry;
|
||||
|
||||
@BeforeAll
|
||||
public static void setUp() {
|
||||
customerRegistry = CustomerRegistry.getInstance();
|
||||
}
|
||||
|
||||
@Test
|
||||
public void shouldBeAbleToAddAndQueryCustomerObjectFromRegistry() {
|
||||
Customer john = new Customer("1", "john");
|
||||
Customer julia = new Customer("2", "julia");
|
||||
|
||||
customerRegistry.addCustomer(john);
|
||||
customerRegistry.addCustomer(julia);
|
||||
|
||||
Customer customerWithId1 = customerRegistry.getCustomer("1");
|
||||
assertNotNull(customerWithId1);
|
||||
assertEquals("1", customerWithId1.getId());
|
||||
assertEquals("john", customerWithId1.getName());
|
||||
|
||||
Customer customerWithId2 = customerRegistry.getCustomer("2");
|
||||
assertNotNull(customerWithId2);
|
||||
assertEquals("2", customerWithId2.getId());
|
||||
assertEquals("julia", customerWithId2.getName());
|
||||
}
|
||||
|
||||
@Test
|
||||
public void shouldReturnNullWhenQueriedCustomerIsNotInRegistry() {
|
||||
Customer customerWithId5 = customerRegistry.getCustomer("5");
|
||||
assertNull(customerWithId5);
|
||||
}
|
||||
|
||||
}
|
@ -1,205 +0,0 @@
|
||||
---
|
||||
layout: pattern
|
||||
title: Bridge
|
||||
folder: bridge
|
||||
permalink: /patterns/bridge/
|
||||
categories: Structural
|
||||
tags:
|
||||
- Gang of Four
|
||||
---
|
||||
|
||||
## 又被称为
|
||||
|
||||
手柄/身体模式
|
||||
|
||||
## 目的
|
||||
|
||||
将抽象与其实现分离,以便二者可以独立变化。
|
||||
|
||||
## 解释
|
||||
|
||||
真实世界例子
|
||||
|
||||
> 考虑一下你拥有一种具有不同附魔的武器,并且应该允许将具有不同附魔的不同武器混合使用。 你会怎么做? 为每个附魔创建每种武器的多个副本,还是只是创建单独的附魔并根据需要为武器设置它? 桥接模式使您可以进行第二次操作。
|
||||
|
||||
通俗的说
|
||||
|
||||
> 桥接模式是一个更推荐组合而不是继承的模式。将实现细节从一个层次结构推送到具有单独层次结构的另一个对象。
|
||||
|
||||
维基百科说
|
||||
|
||||
> 桥接模式是软件工程中使用的一种设计模式,旨在“将抽象与其实现分离,从而使两者可以独立变化”
|
||||
|
||||
**程序示例**
|
||||
|
||||
翻译一下上面的武器示例。下面我们有武器的类层级:
|
||||
|
||||
```java
|
||||
public interface Weapon {
|
||||
void wield();
|
||||
void swing();
|
||||
void unwield();
|
||||
Enchantment getEnchantment();
|
||||
}
|
||||
|
||||
public class Sword implements Weapon {
|
||||
|
||||
private final Enchantment enchantment;
|
||||
|
||||
public Sword(Enchantment enchantment) {
|
||||
this.enchantment = enchantment;
|
||||
}
|
||||
|
||||
@Override
|
||||
public void wield() {
|
||||
LOGGER.info("The sword is wielded.");
|
||||
enchantment.onActivate();
|
||||
}
|
||||
|
||||
@Override
|
||||
public void swing() {
|
||||
LOGGER.info("The sword is swinged.");
|
||||
enchantment.apply();
|
||||
}
|
||||
|
||||
@Override
|
||||
public void unwield() {
|
||||
LOGGER.info("The sword is unwielded.");
|
||||
enchantment.onDeactivate();
|
||||
}
|
||||
|
||||
@Override
|
||||
public Enchantment getEnchantment() {
|
||||
return enchantment;
|
||||
}
|
||||
}
|
||||
|
||||
public class Hammer implements Weapon {
|
||||
|
||||
private final Enchantment enchantment;
|
||||
|
||||
public Hammer(Enchantment enchantment) {
|
||||
this.enchantment = enchantment;
|
||||
}
|
||||
|
||||
@Override
|
||||
public void wield() {
|
||||
LOGGER.info("The hammer is wielded.");
|
||||
enchantment.onActivate();
|
||||
}
|
||||
|
||||
@Override
|
||||
public void swing() {
|
||||
LOGGER.info("The hammer is swinged.");
|
||||
enchantment.apply();
|
||||
}
|
||||
|
||||
@Override
|
||||
public void unwield() {
|
||||
LOGGER.info("The hammer is unwielded.");
|
||||
enchantment.onDeactivate();
|
||||
}
|
||||
|
||||
@Override
|
||||
public Enchantment getEnchantment() {
|
||||
return enchantment;
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
这里是单独的附魔类结构:
|
||||
|
||||
```java
|
||||
public interface Enchantment {
|
||||
void onActivate();
|
||||
void apply();
|
||||
void onDeactivate();
|
||||
}
|
||||
|
||||
public class FlyingEnchantment implements Enchantment {
|
||||
|
||||
@Override
|
||||
public void onActivate() {
|
||||
LOGGER.info("The item begins to glow faintly.");
|
||||
}
|
||||
|
||||
@Override
|
||||
public void apply() {
|
||||
LOGGER.info("The item flies and strikes the enemies finally returning to owner's hand.");
|
||||
}
|
||||
|
||||
@Override
|
||||
public void onDeactivate() {
|
||||
LOGGER.info("The item's glow fades.");
|
||||
}
|
||||
}
|
||||
|
||||
public class SoulEatingEnchantment implements Enchantment {
|
||||
|
||||
@Override
|
||||
public void onActivate() {
|
||||
LOGGER.info("The item spreads bloodlust.");
|
||||
}
|
||||
|
||||
@Override
|
||||
public void apply() {
|
||||
LOGGER.info("The item eats the soul of enemies.");
|
||||
}
|
||||
|
||||
@Override
|
||||
public void onDeactivate() {
|
||||
LOGGER.info("Bloodlust slowly disappears.");
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
这里是两种层次结构的实践:
|
||||
|
||||
```java
|
||||
var enchantedSword = new Sword(new SoulEatingEnchantment());
|
||||
enchantedSword.wield();
|
||||
enchantedSword.swing();
|
||||
enchantedSword.unwield();
|
||||
// The sword is wielded.
|
||||
// The item spreads bloodlust.
|
||||
// The sword is swinged.
|
||||
// The item eats the soul of enemies.
|
||||
// The sword is unwielded.
|
||||
// Bloodlust slowly disappears.
|
||||
|
||||
var hammer = new Hammer(new FlyingEnchantment());
|
||||
hammer.wield();
|
||||
hammer.swing();
|
||||
hammer.unwield();
|
||||
// The hammer is wielded.
|
||||
// The item begins to glow faintly.
|
||||
// The hammer is swinged.
|
||||
// The item flies and strikes the enemies finally returning to owner's hand.
|
||||
// The hammer is unwielded.
|
||||
// The item's glow fades.
|
||||
```
|
||||
|
||||
|
||||
|
||||
## 类图
|
||||
|
||||

|
||||
|
||||
## 适用性
|
||||
|
||||
使用桥接模式当
|
||||
|
||||
* 你想永久性的避免抽象和他的实现之间的绑定。有可能是这种情况,当实现需要被选择或者在运行时切换。
|
||||
* 抽象和他们的实现应该能通过写子类来扩展。这种情况下,桥接模式让你可以组合不同的抽象和实现并独立的扩展他们。
|
||||
* 对抽象的实现的改动应当不会对客户产生影响;也就是说,他们的代码不必重新编译。
|
||||
* 你有种类繁多的类。这样的类层次结构表明需要将一个对象分为两部分。Rumbaugh 使用术语“嵌套归纳”来指代这种类层次结构。
|
||||
* 你想在多个对象间分享一种实现(可能使用引用计数),这个事实应该对客户隐藏。一个简单的示例是Coplien的String类,其中多个对象可以共享同一字符串表示形式
|
||||
|
||||
## 教程
|
||||
|
||||
* [Bridge Pattern Tutorial](https://www.journaldev.com/1491/bridge-design-pattern-java)
|
||||
|
||||
## 鸣谢
|
||||
|
||||
* [Design Patterns: Elements of Reusable Object-Oriented Software](https://www.amazon.com/gp/product/0201633612/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0201633612&linkCode=as2&tag=javadesignpat-20&linkId=675d49790ce11db99d90bde47f1aeb59)
|
||||
* [Head First Design Patterns: A Brain-Friendly Guide](https://www.amazon.com/gp/product/0596007124/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0596007124&linkCode=as2&tag=javadesignpat-20&linkId=6b8b6eea86021af6c8e3cd3fc382cb5b)
|
@ -33,6 +33,8 @@ tags:
|
||||
|
||||
以巨魔的为例。首先我有有一个简单的巨魔,实现了巨魔接口。
|
||||
|
||||
程序mple. First of all we have a simple troll implementing the troll interface
|
||||
|
||||
```java
|
||||
public interface Troll {
|
||||
void attack();
|
||||
|
@ -1,101 +0,0 @@
|
||||
---
|
||||
layout: pattern
|
||||
title: Dependency Injection
|
||||
folder: dependency-injection
|
||||
permalink: /patterns/dependency-injection/
|
||||
categories: Creational
|
||||
tags:
|
||||
- Decoupling
|
||||
---
|
||||
|
||||
## 目的
|
||||
|
||||
依赖注入是一种软件设计模式,其中一个或多个依赖项(或服务)被注入或通过引用传递到一个依赖对象(或客户端)中,并成为客户端状态的一部分。该模式将客户的依赖关系的创建与其自身的行为分开,这使程序设计可以松散耦合,并遵循控制反转和单一职责原则。
|
||||
|
||||
## 解释
|
||||
|
||||
真实世界例子
|
||||
|
||||
> 老巫师喜欢不时地装满烟斗抽烟。 但是,他不想只依赖一个烟草品牌,而是希望能够互换使用它们。
|
||||
|
||||
通俗的说
|
||||
|
||||
> 依赖注入将客户端依赖的创建与其自身行为分开。
|
||||
|
||||
维基百科说
|
||||
|
||||
> 在软件工程中,依赖注入是一种对象接收其依赖的其他对象的技术。 这些其他对象称为依赖项。
|
||||
|
||||
**程序示例**
|
||||
|
||||
先介绍一下烟草接口和具体的品牌。
|
||||
|
||||
```java
|
||||
public abstract class Tobacco {
|
||||
|
||||
private static final Logger LOGGER = LoggerFactory.getLogger(Tobacco.class);
|
||||
|
||||
public void smoke(Wizard wizard) {
|
||||
LOGGER.info("{} smoking {}", wizard.getClass().getSimpleName(),
|
||||
this.getClass().getSimpleName());
|
||||
}
|
||||
}
|
||||
|
||||
public class SecondBreakfastTobacco extends Tobacco {
|
||||
}
|
||||
|
||||
public class RivendellTobacco extends Tobacco {
|
||||
}
|
||||
|
||||
public class OldTobyTobacco extends Tobacco {
|
||||
}
|
||||
```
|
||||
|
||||
下面是老巫师的类的层次结构。
|
||||
|
||||
```java
|
||||
public interface Wizard {
|
||||
|
||||
void smoke();
|
||||
}
|
||||
|
||||
public class AdvancedWizard implements Wizard {
|
||||
|
||||
private final Tobacco tobacco;
|
||||
|
||||
public AdvancedWizard(Tobacco tobacco) {
|
||||
this.tobacco = tobacco;
|
||||
}
|
||||
|
||||
@Override
|
||||
public void smoke() {
|
||||
tobacco.smoke(this);
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
最后我们可以看到给老巫师任意品牌的烟草是多么的简单。
|
||||
|
||||
```java
|
||||
var advancedWizard = new AdvancedWizard(new SecondBreakfastTobacco());
|
||||
advancedWizard.smoke();
|
||||
```
|
||||
|
||||
## 类图
|
||||
|
||||

|
||||
|
||||
## 适用性
|
||||
|
||||
使用依赖注入当:
|
||||
|
||||
- 当你需要从对象中移除掉具体的实现内容时
|
||||
|
||||
* 使用模拟对象或存根隔离地启用类的单元测试
|
||||
|
||||
## 鸣谢
|
||||
|
||||
* [Dependency Injection Principles, Practices, and Patterns](https://www.amazon.com/gp/product/161729473X/ref=as_li_qf_asin_il_tl?ie=UTF8&tag=javadesignpat-20&creative=9325&linkCode=as2&creativeASIN=161729473X&linkId=57079257a5c7d33755493802f3b884bd)
|
||||
* [Clean Code: A Handbook of Agile Software Craftsmanship](https://www.amazon.com/gp/product/0132350882/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0132350882&linkCode=as2&tag=javadesignpat-20&linkId=2c390d89cc9e61c01b9e7005c7842871)
|
||||
* [Java 9 Dependency Injection: Write loosely coupled code with Spring 5 and Guice](https://www.amazon.com/gp/product/1788296257/ref=as_li_tl?ie=UTF8&tag=javadesignpat-20&camp=1789&creative=9325&linkCode=as2&creativeASIN=1788296257&linkId=4e9137a3bf722a8b5b156cce1eec0fc1)
|
||||
* [Google Guice Tutorial: Open source Java based dependency injection framework](https://www.amazon.com/gp/product/B083P7DZ8M/ref=as_li_tl?ie=UTF8&tag=javadesignpat-20&camp=1789&creative=9325&linkCode=as2&creativeASIN=B083P7DZ8M&linkId=04f0f902c877921e45215b624a124bfe)
|
Reference in New Issue
Block a user