When the cold wind of winter brushes over the earth, the snow and ice economy is like a bright pearl, emitting a fiery charm in the cold. Ski resorts, ice sculpture exhibitions, ice and snow theme hotels and other types of snow and ice industry is booming, the logic and strategy behind the operation, and Java design patterns have a marvelous similarity, for us to deeply understand and use Java design patterns provide a unique perspective.
I. Factory model: "production base" for ice and snow projects
In the ice and snow economy, different types of ice and snow recreation programs are like products produced by factories. For example, a large snow park has a variety of snow and ice facilities, such as ski slopes, ice skating rinks, ice slides, and so on. This can be compared to Java's factory pattern, which encapsulates the process of creating these different snow and ice projects in a "factory" class.
Suppose we have aIceProjectFactoryclass, which creates different ice project objects based on the parameters passed in. The code example is as follows:
interface IceProject {
void operate();
}
class SkiSlope implements IceProject {
@Override
public void operate() {
("Ski Resort in operation，People skiing to their heart's content。");
}
}
class IceSkatingRink implements IceProject {
@Override
public void operate() {
("The rink is buzzing with activity，People dancing on the ice.。");
}
}
class IceProjectFactory {
public static IceProject createProject(String type) {
if ("ski".equals(type)) {
return new SkiSlope();
} else if ("skate".equals(type)) {
return new IceSkatingRink();
}
return null;
}
}
In this example, theIceProjectFactoryIt is like the project creation center of the ice park, according to the demand to create different instances of ice projects, which is consistent with the factory pattern through the factory class to create the object of the same idea, so that the creation of the code logic is more clear, easy to maintain and extend. When the ice park wants to add a new ice project, you only need to add the corresponding creation logic in the factory class, without affecting other parts of the code.
II. The single-case model: "sole resource management" in the ice economy
In the snow economy, certain resources are unique and need to be shared globally, such as the snowmaking system in a snow park. The snow maintenance of the entire park depends on this one snow system, which is like the singleton pattern in Java.
The following is sample code for the singleton pattern:
class SnowMakingSystem {
private static SnowMakingSystem instance;
private SnowMakingSystem() {
// private constructor，Prevent direct external instance creation
}
public static SnowMakingSystem getInstance() {
if (instance == null) {
synchronized () {
if (instance == null) {
instance = new SnowMakingSystem();
}
}
}
return instance;
}
public void makeSnow() {
("The snow-making system is working，Making snowflakes for the ice park。");
}
}
In this code, theSnowMakingSystemconstructor is privatized and can only be accessed through thegetInstancemethod to get the unique instance. This ensures that there is only one snow-making system working in the whole operation of the ice park, avoiding waste of resources and conflicts, just like in Java applications, certain global configuration management classes or database connection pools and other resources are suitable for the use of the singleton pattern to ensure the uniqueness and consistency of the resources.
III. Strategy model: "flexible strategy" for snow and ice tourism packages
Ice and snow tourism enterprises often offer different tour packages to meet the needs of different tourists. For example, there are economy packages, luxury packages, family packages, etc. Each package contains different service combinations and pricing strategies. This is similar to Java's strategy pattern.
We can define a policy interfaceTourPackageStrategy, and then different package strategy classes implement this interface:
interface TourPackageStrategy {
void offerPackage();
}
class EconomyPackageStrategy implements TourPackageStrategy {
} class EconomyPackageStrategy implements TourPackageStrategy { @Override
public void offerPackage() {
("Offer an economy snow and ice tour package with basic snow and ice program experience and simple accommodation.") ;
}
}
class LuxuryPackageStrategy implements TourPackageStrategy {
class LuxuryPackageStrategy implements TourPackageStrategy { @Override
public void offerPackage() {
("Offer a luxury snow and ice tour package with high-end snow and ice programs, luxury accommodations and exclusive services.") ;
}
}
class FamilyPackageStrategy implements TourPackageStrategy {
} class FamilyPackageStrategy implements TourPackageStrategy { @Override
public void offerPackage() {
("Offer a family-oriented ice and snow tour package with family-friendly ice and snow entertainment programs and interactive parent-child activities.") ;
}
}
Tourism companies can then apply different strategies depending on the choices made by tourists:
class TourCompany {
private TourPackageStrategy strategy;
public void setStrategy(TourPackageStrategy strategy) {
= strategy;
}
public void promotePackage() {
();
}
}
With this strategy pattern, travel companies can easily switch between different package strategies without having to modify a lot of code. In Java applications, when there are multiple algorithms or strategies that can solve the same problem, the policy pattern can make the code more flexible and maintainable, for example, it can be applied in scenarios such as different promotional strategies in e-commerce systems or the selection of payment methods.
IV. The observer model: "information dissemination" for snow and ice events
In ice and snow events, information such as athletes' results and event developments need to be communicated in a timely manner to spectators, media and relevant sports organizations. This can be compared to Java's observer pattern, where the athlete or event organizer is the object to be observed, and the audience, media, etc. are the observers.
First define an observer interfaceIceEventObserver：
interface IceEventObserver {
void update(String eventInfo);
}
Then there is the theme category of the event being observedIceEventSubject：
import ;
import ;
class IceEventSubject {
private List<IceEventObserver> observers = new ArrayList<>();
private String eventInfo;
public void attachObserver(IceEventObserver observer) {
(observer);
}
public void detachObserver(IceEventObserver observer) {
(observer);
}
public void setEventInfo(String eventInfo) {
= eventInfo;
notifyObservers();
}
private void notifyObservers() {
for (IceEventObserver observer : observers) {
(eventInfo);
}
}
}
For example, there is the audience and the media as observers:
class Audience implements IceEventObserver {
@Override
public void update(String eventInfo) {
("Viewers get the message：" + eventInfo);
}
}
class Media implements IceEventObserver {
@Override
public void update(String eventInfo) {
("The press got the message.：" + eventInfo);
// The media may conduct further operations such as news coverage
}
}
In practice, when something new happens in an event, such as when an athlete breaks a record, the event organizer can besetEventInfoWhen a method updates information, all observers are notified and react accordingly. In Java applications, the observer pattern is often used to implement the event listening mechanism, such as button clicking events in GUI programming, message processing in the message queue and other scenarios, which can effectively realize the decoupling between the objects and improve the flexibility and scalability of the system.
Various operation modes and scenarios in the snow and ice economy provide vivid cases for us to understand Java design patterns. By linking the snow and ice economy with Java design patterns, we can better grasp the application scenarios and advantages of these design patterns, so that we can utilize them more skillfully in Java programming to create more efficient, flexible, and maintainable software systems, which, just like the carefully operated snow and ice industry, can operate stably and excellently under different demands and environments.
Author:Mr. Die's Programming Class
Provenance:/
If you like this article, please long press the QR code, attention!Java Code World Exploration
.