Service governance

Eureka

• Service governance server (Eureka server, registration center): service registration center, which is responsible for the registration, maintenance, query and other functions of service list, that is, Eureka server.
• Service registration agent (service provider): if a microservice is a service provider, the service configuration information can be registered to the governance server through the service registration agent. The service registration agent can be understood as an Eureka client, which is responsible for registering, renewing and logging off the services provided by the micro service to Eureka server, so that service consumers can discover and consume. When registering the service, you need to provide the service governance server with the service name, host server IP address, service port number, domain name and other main data.
• Service discovery client (service consumer): also an Eureka client. When it starts, it will get all the service registry information from the service governance server by default, and consume the corresponding service through the obtained service registration list information.

Service governance server (service registry) profile:

spring.application.name=servicediscovery
#Port number. If it is not set, it is the default port 8080 of boot
server.port=8260
#Corresponding configuration of eureka
eureka.instance.hostname=localhost
eureka.server.wait-time-in-ms-when-sync-empty=5
#Whether the startup service registers the service to the service governance server is false (production) because it is the service governance server itself
eureka.client.register-with-eureka=false
eureka.client.service-url.defaultZone=http://${eureka.instance.hostname}:${server.port}/eureka
#Indicates that the registered service registration list data does not need to be synchronized from the service governance server to the local (consumption) after the application is started
eureka.client.fetch-registry=false

Service provider profile:

server.port=2100
#service name
spring.application.name=userservice
eureka.instance.prefer-ip-address=true
eureka.client.register-with-eureka=true
eureka.client.fetch-registry=true
#server address
eureka.client.service-url.defaultZone=http://localhost:8260/eureka

How can I find the service after a long time?

package com.cd826dong.clouddemo.product.api;

import com.cd826dong.clouddemo.product.entity.ProductComment;
import com.cd826dong.clouddemo.product.repository.ProductRepository;
import com.cd826dong.clouddemo.product.entity.Product;
import com.cd826dong.clouddemo.product.repository.ProductCommentRepository;
import com.cd826dong.clouddemo.product.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;

import java.util.Collections;
import java.util.List;
import java.util.stream.Collectors;

/**
 * Endpoint of product management
 *
 * @author CD826
 * @since 1.0.0
 */
@RestController
@RequestMapping("/products")
public class ProductEndpoint {
    @Autowired
    private ProductRepository productRepository;
    @Autowired
    private ProductCommentRepository productCommentRepository;

    @Autowired
    @Qualifier(value = "restTemplate")
    private RestTemplate restTemplate;

    /**
     * Get product information list
     * @return
     */
    @RequestMapping(method = RequestMethod.GET)
    public List<Product> list() {
        return this.productRepository.findAll();
    }

    @RequestMapping(value = "/{id}", method = RequestMethod.GET)
    public Product detail(@PathVariable Long id){
        return this.productRepository.findOne(id);
    }

    @RequestMapping(value = "/{id}/comments", method = RequestMethod.GET)
    public List<ProductCommentDto> comments(@PathVariable Long id){
        List<ProductComment> commentList = this.productCommentRepository.findByProductIdOrderByCreated(id);
        if (null == commentList || commentList.isEmpty())
            return Collections.emptyList();

        return commentList.stream().map((comment) -> {
            ProductCommentDto dto = new ProductCommentDto(comment);
            dto.setProduct(this.productRepository.findOne(comment.getProductId()));
            dto.setAuthor(this.loadUser(comment.getAuthorId()));
            return dto;
        }).collect(Collectors.toList());
    }

    /**
     * Load the user information of comment author through RestTemplate
     * @param userId User Id
     * @return
     */
    protected UserDto loadUser(Long userId) {
        return this.restTemplate.getForEntity("http://localhost:8280/userservice/users/{id}", UserDto.class, userId).getBody();
    }
}

/**
* Service consumers
*/
@EnableDiscoveryClient
@SpringBootApplication
public class Application {
    @Bean(value = "restTemplate")
    RestTemplate restTemplate() {
        return new RestTemplate();
    }

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}