详解使用Spring Cloud Consul实现服务的注册和发现

首先安装consul环境，参照之前的文章：https://www.jb51.net/article/141789.htm

项目规划，2个服务端，1个客户端

首先来看服务端，

一：服务端1：

项目依赖

<dependencyManagement>
 <dependencies>
   <dependency>
     <groupId>org.springframework.cloud</groupId>
     <artifactId>spring-cloud-consul-dependencies</artifactId>
     <version>1.0.1.RELEASE</version>
     <type>pom</type>
     <scope>import</scope>
   </dependency>
 </dependencies>
</dependencyManagement>

<dependencies>
 <dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-actuator</artifactId>
   <version>1.3.5.RELEASE</version>
 </dependency>
 <dependency>
   <groupId>org.springframework.cloud</groupId>
   <artifactId>spring-cloud-starter-consul-discovery</artifactId>
 </dependency>
</dependencies>

注意，增加spring-boot-actuator是为了项目可以访问/health 路径来判断服务是否健康

package com.pp.consul1;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@SpringBootApplication
@EnableDiscoveryClient
@RestController
public class ConsulApp {

@RequestMapping("/home")
 public Object home() {
   System.out.println("1111111111111");
   return "OK11";
 }

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

application.properties 配置内容

server.port=9955  
spring.application.name=Consul-Server-1
spring.cloud.consul.host=192.168.1.100
spring.cloud.consul.port=8500
spring.cloud.consul.enabled=true
spring.cloud.consul.discovery.enabled=true
spring.cloud.consul.discovery.instanceId=tomcat1
spring.cloud.consul.discovery.serviceName=tomcat
spring.cloud.consul.discovery.hostname=192.168.2.95
spring.cloud.consul.discovery.port=${server.port}
spring.cloud.consul.discovery.healthCheckUrl=http://192.168.2.95:9955/health
spring.cloud.consul.discovery.healthCheckInterval=10s
spring.cloud.consul.discovery.tags=dev

看过我之前文章的，应该对这些配置很清楚了。这样，一个服务端就配置写好了。

由于我们增加了@EnableDiscoveryClient注解，所以，系统启动的时候，就会向consul注册一个服务，服务的名字为tomcat, ID为tomcat1

访问consul的HTTP API /v1/catalog/service/tomcat 输出如下：

{
 "Node":"192.168.1.100",
 "Address":"192.168.1.100",
 "ServiceID":"tomcat1",
 "ServiceName":"tomcat",
 "ServiceTags":["dev"],
 "ServiceAddress":"192.168.2.95",
 "ServicePort":9955,
 "ServiceEnableTagOverride":false,
 "CreateIndex":993,
 "ModifyIndex":1057
}

二：服务端2

项目依赖和上面一样 

package com.pp.consul2;  
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@SpringBootApplication
@EnableDiscoveryClient
@RestController
public class ConsulApp {

@RequestMapping("/home")
 public Object home() {
   System.out.println("2222222222222222");
   return "OK22";
 }

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

application.properties 配置内容：

server.port=9966

spring.application.name=Consul-Server-2
spring.cloud.consul.host=192.168.1.100
spring.cloud.consul.port=8500
spring.cloud.consul.enabled=true
spring.cloud.consul.discovery.enabled=true
spring.cloud.consul.discovery.instanceId=tomcat2
spring.cloud.consul.discovery.serviceName=tomcat
spring.cloud.consul.discovery.hostname=192.168.2.95
spring.cloud.consul.discovery.port=${server.port}
spring.cloud.consul.discovery.healthCheckUrl=http://192.168.2.95:9966/health
spring.cloud.consul.discovery.healthCheckInterval=10s
spring.cloud.consul.discovery.tags=test

三：客户端

项目依赖，只需要spring-cloud-starter-consul-discovery

application.properties 配置内容：

server.port=9977

spring.application.name=Consul-Client
spring.cloud.consul.host=192.168.1.100
spring.cloud.consul.port=8500
spring.cloud.consul.discovery.register=false

注意，这里的spring.cloud.consul.discovery.register需要配置成false，否则系统启动的时候，会向consul注册一个服务

package com.pp.client;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.DiscoveryClient;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@SpringBootApplication
@EnableDiscoveryClient
@RestController
public class ConsulClient {

@Autowired
 private LoadBalancerClient loadBalancer;

@Autowired
 private DiscoveryClient discoveryClient;

/**
  * 从所有服务中选择一个服务（轮询）
  */
 @RequestMapping("/discover")
 public Object discover() {
   return loadBalancer.choose("tomcat").getUri().toString();
 }

/**
  * 获取所有服务
  */
 @RequestMapping("/services")
 public Object services() {
   return discoveryClient.getInstances("tomcat");
 }

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

启动之后，就可以访问/discover，/services 查看效果了。

来源：https://blog.csdn.net/mn960mn/article/details/51775212