mirror of
https://github.com/tiennm99/java-design-patterns.git
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tmcconville
45 lines
2.2 KiB
Java
45 lines
2.2 KiB
Java
package com.iluwatar.api.gateway;
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import org.springframework.boot.SpringApplication;
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import org.springframework.boot.autoconfigure.SpringBootApplication;
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/**
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* With the Microservices pattern, a client may need data from multiple different microservices.
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* If the client called each microservice directly, that could contribute to longer load times,
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* since the client would have to make a network request for each microservice called. Moreover,
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* having the client call each microservice directly ties the client to that microservice - if the
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* internal implementations of the microservices change (for example, if two microservices are
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* combined sometime in the future) or if the location (host and port) of a microservice changes,
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* then every client that makes use of those microservices must be updated.
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*
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* <p>
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* The intent of the API Gateway pattern is to alleviate some of these issues. In the API Gateway
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* pattern, an additional entity (the API Gateway) is placed between the client and the
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* microservices. The job of the API Gateway is to aggregate the calls to the microservices.
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* Rather than the client calling each microservice individually, the client calls the API Gateway
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* a single time. The API Gateway then calls each of the microservices that the client needs.
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*
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* <p>
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* This implementation shows what the API Gateway pattern could look like for an e-commerce site.
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* The {@link ApiGateway} makes calls to the Image and Price microservices using the
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* {@link ImageClientImpl} and {@link PriceClientImpl} respectively. Customers viewing the site on a
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* desktop device can see both price information and an image of a product, so the {@link ApiGateway}
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* calls both of the microservices and aggregates the data in the {@link DesktopProduct} model.
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* However, mobile users only see price information; they do not see a product image. For mobile
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* users, the {@link ApiGateway} only retrieves price information, which it uses to populate the
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* {@link MobileProduct}.
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*/
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@SpringBootApplication
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public class App {
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/**
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* Program entry point
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*
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* @param args
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* command line args
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*/
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public static void main(String[] args) {
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SpringApplication.run(App.class, args);
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}
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}
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