Use of resttemplate and Eureka

RestTemplate Use

Write

Let this remote call template register to Spring Inside the container

@Bean
    public RestTemplate restTemplate(){
        return new RestTemplate();
    }

Business level write

  @Autowired
    private RestTemplate restTemplate;

You can call get perhaps post The method

get Namely getforboj that post Namely postobj 

Test cases

Before use user Inside is null, Use RestTemplate Remote call query , Return the data

 @Autowired
    private RestTemplate restTemplate;

    public Order queryOrderById(Long orderId) {
        // 1. Query order 
        Order order = orderMapper.findById(orderId);
        // 2.  create http request url
        String url = "http://localhost:8081/user/"+order.getUserId();
        // 3. Send the request and convert the format 
        User user = restTemplate.getForObject(url, User.class);
        // 4. return 
        order.setUser(user);
        return order;
    }

 

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Eureka What is a registry

What is a service provider and what is a consumer

Service providers ： In a business , Services invoked by other microservices .（ Provide interfaces to other microservices ）

Serving consumers ： In a business , Call the services of other microservices .（ Call interfaces provided by other microservices ）

Consumers can also be providers , Providers will also be consumers .

above RestTemplate What happened

How can service consumers get the address information of service providers ？

If there are multiple service providers , How consumers choose ？

How consumers know the health status of service providers ？

Then use the image Eureka Registration center such a registration center solves

 Eureka The role of the registry

 

In fact, it is to help manage the service interface , Monitor whether the interface is healthy  

Official words ：

 

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Eureka Use  

Set up a registration center Eureka Registry Center

New module  

because Eureka You need a module of your own to run

So before you cloud Create a new sub project under the project

Import dependencies in subprojects  

<dependency>
   <groupId>org.springframework.cloud</groupId>
   <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
</dependency>

Start class

add  @EnableEurekaServer open Eureka

 

  The configuration file

server:
  port: 10086

spring:
  application:
    name: lanlandaimaren # The service name   Name yourself as you like 

eureka:
  client:
    service-url:
      defaultZone: http://127.0.0.1:10086/eureka/  #eureka Service address , The port is set above 

  Start project

  Direct access to your port ：http://localhost:10086/

 

 

---

register user-service Registration service

Add dependencies under the service module you want to add

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>

  The configuration file

spring:
 application:
    name:userservice # Service name   ditto 

eureka:
  client:
    service-url:
      defaultZone: http://127.0.0.1:10086/eureka/ # Same address as above 

 

In this way, the service is registered

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Service discovery  

The previous method

This is the method used above, so what should we do now , speak localhost Replace with a service name such as ：

 @Autowired
    private RestTemplate restTemplate;

    public Order queryOrderById(Long orderId) {
        // 1. Query order 
        Order order = orderMapper.findById(orderId);
        // 2.  create http request url
        String url = "http://userservice/user/" +order.getUserId();
        // 3. Send the request and convert the format 
        User user = restTemplate.getForObject(url, User.class);
        // 4. return 
        order.setUser(user);
        return order;
    }

  The effect is the same

 

Ribbon Load balancing

 

 

Thanks for the open source materials of dark horse , Provide learning  

such RestTemplate and Eureka The use of is over .