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This article mainly explains "how to create the OpenFeign project of SpringCloud". The content in the article is simple and clear, and it is easy to learn and understand. Please follow the editor's train of thought to study and learn how to create the OpenFeign project of SpringCloud.

What is OpenFeign?

OpenFeign is a declarative Http client, and it is very simple to send Http requests through OpenFeign

Annotated development, interface + annotation OpenFeign supports a variety of object serialization and deserialization tools OpenFeign integrates Ribbon by default, which can be used for load balancing directly

Feign and OpenFeign are two technologies, both exist as service invocation. OpenFeign is encapsulated by SpringCloud on the basis of Feign and supports SpringMvc annotations.

Create a project for OpenFeign

1. Create a new Module project cloud-openfeign-8806

2.pom file import dependency

Cloud-demo-20f

Com.lby

1.0-SNAPSHOT

4.0.0

Cloud-openfeign-8806

Org.springframework.cloud

Spring-cloud-starter-openfeign

Org.springframework.cloud

Spring-cloud-starter-netflix-eureka-client

Org.springframework.boot

Spring-boot-starter-web

Org.springframework.boot

Spring-boot-starter-test

Test

3. Startup class

Package com.lby

Import org.springframework.boot.SpringApplication

Import org.springframework.boot.autoconfigure.SpringBootApplication

Import org.springframework.cloud.client.discovery.EnableDiscoveryClient

Import org.springframework.cloud.openfeign.EnableFeignClients

/ * *

Notes on * @ EnableFeignClients OpenFeign

, /

@ SpringBootApplication

@ EnableDiscoveryClient

@ EnableFeignClients

Public class OpenFeignRun8806 {

Public static void main (String [] args) {

SpringApplication.run (OpenFeignRun8806.class,args)

}

}

4. Configuration file

Server:

Port: 8806

# specify that the name of the current service will be registered with the registry

Spring:

Application:

Name: eureka-openfeign-8806

# specify the address of the service registry

Eureka:

Client:

ServiceUrl:

DefaultZone: http://localhost:8801/eureka,http://localhost:8800/eureka

We have the most preliminary project in four steps, and then we will develop the service invocation of OpenFeign through interface + annotation.

Development of OpenFeign Interface

OpenFeign development mode: interface + annotations, micro service invocation interface + @ FeignClient is similar to Dao interface development (Mybatis interface development). Before we developed Dao interface, we added @ Mapper annotation to the interface to get a Mybatis interface.

1. Business logic interface + @ FeignClient creates OpenFeign service invocation

Package com.lby.service

Import org.springframework.cloud.openfeign.FeignClient

Import org.springframework.stereotype.Component

Import org.springframework.web.bind.annotation.GetMapping

Import org.springframework.web.bind.annotation.RequestParam

/ * *

* @ author luxiaoyang

* @ create 2020-04-05-19:41

*

The * @ FeignClient parameter is the name of the service to be requested

, /

@ Component

@ FeignClient (value = "eureka-client-8803")

Public interface ConsumerFeignService {

/ * *

* the method in the interface is the Controller interface of the called service

, /

@ GetMapping ("showImgById")

String showImgById (@ RequestParam ("id") Integer id)

}

The writing rules of the interface are shown in the following figure:

two。 Create a ConsumerController in the consumer using the OpenFeign interface

Package com.lby.controller

Import com.lby.service.ConsumerFeignService

Import org.springframework.web.bind.annotation.GetMapping

Import org.springframework.web.bind.annotation.RestController

Import javax.annotation.Resource

/ * *

* @ author luxiaoyang

* @ create 2020-04-05-19:47

, /

@ RestController

Public class ConsumerController {

/ * *

* directly assemble the service invocation interface of OpenFeign

, /

@ Resource

Private ConsumerFeignService consumerFeignService

@ GetMapping ("testOpenFeign")

Public String testOpenFeign () {

String s = consumerFeignService.showImgById (1)

The result of the return "Feign service call is:" + s

}

}

Start the project

Start the registry, service providers (two), and Feign services

Request the Controller API of eureka-openfeign-8806: http://127.0.0.1:8806/testOpenFeign

You can see that both requests can get the response of the service provider and can be load balanced

Thank you for reading, the above is the content of "how to create the OpenFeign project of SpringCloud". After the study of this article, I believe you have a deeper understanding of how to create the OpenFeign project of SpringCloud, and the specific use needs to be verified in practice. Here is, the editor will push for you more related knowledge points of the article, welcome to follow!

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