源码
GitHub:https://github.com/291685399/springcloud-learning/tree/master/springcloud-eureka03
目标
上一篇SpringCloud(二)eureka注册中心的使用介绍如何使用eureka,但是在实际使用中,一般都是集群,下面介绍如何给eureka server搭建集群,同时client连接集群
eureka的使用
- 新建一个父工程,命名为springcloud-eureka03
目录结构如下图:
![](https://img.laitimes.com/img/9ZDMuAjOiMmIsIjOiQnIsIyZuBnL4kjNwAjN1ATMyIjNwkTMwIzLc52YucWbp5GZzNmLn9Gbi1yZtl2Lc9CX6MHc0RHaiojIsJye.png)
pom.xml:
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.4.RELEASE</version>
<relativePath/>
</parent>
<dependencies>
<!-- springboot -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
- 新建模块,命名为eureka-server03_1
目录结构如下图:
pom.xml:
<parent>
<groupId>com.wyj</groupId>
<artifactId>springcloud-eureka03</artifactId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<properties>
<java.version>1.8</java.version>
<spring-cloud.version>Finchley.SR1</spring-cloud.version>
</properties>
<dependencies>
<!-- springcloud eureka server -->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
在启动器EurekaServer03_1Application上添加注解用于开启eureka server
@SpringBootApplication
@EnableEurekaServer
public class EurekaServer03_1Application {
public static void main(String[] args) {
SpringApplication.run(EurekaServer03_1Application.class, args);
}
}
在application.properties:
注意:
1、这里的端口,eureka-server03_1的端口是10000,后面新建的模块eureka-server03_2端口为10001,所以它需要连接的eureka server地址为http://127.0.0.1:10001/eureka,当然eureka-server03_2需要连接的eureka-server地址为http://127.0.0.1:10000/eureka,这样才能给eureka server形成一个集群
2、需要将之前使用eureka配置中的eureka.client.register-with-eureka=false和eureka.client.fetch-registry=false注释
server.port=10000
spring.application.name:eureka-server
# 是否注册自己的信息到EurekaServer,默认是true
#eureka.client.register-with-eureka=false
# 是否拉取其它服务的信息,默认是true
#eureka.client.fetch-registry=false
# EurekaServer的地址,现在是自己的地址,如果是集群,需要加上其它Server的地址
eureka.client.service-url.defaultZone:http://127.0.0.1:10001/eureka
- 新建模块,命名为eureka-server03_2
目录结构如下图:
pom.xml:
<parent>
<groupId>com.wyj</groupId>
<artifactId>springcloud-eureka03</artifactId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<properties>
<java.version>1.8</java.version>
<spring-cloud.version>Finchley.SR1</spring-cloud.version>
</properties>
<dependencies>
<!-- springcloud eureka server -->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
在启动器EurekaServer03_2Application上添加注解用于开启eureka server
@SpringBootApplication
@EnableEurekaServer
public class EurekaServer03_2Application {
public static void main(String[] args) {
SpringApplication.run(EurekaServer03_2Application.class, args);
}
}
在application.properties:
注意:
1、这里的端口,eureka-server03_1的端口是10000,后面新建的模块eureka-server03_2端口为10001,所以它需要连接的eureka server地址为http://127.0.0.1:10000/eureka,当然eureka-server03_2需要连接的eureka-server地址为http://127.0.0.1:10000/eureka,这样才能给eureka server形成一个集群
2、需要将之前使用eureka配置中的eureka.client.register-with-eureka=false和eureka.client.fetch-registry=false注释
server.port=10000
spring.application.name:eureka-server
# 是否注册自己的信息到EurekaServer,默认是true
#eureka.client.register-with-eureka=false
# 是否拉取其它服务的信息,默认是true
#eureka.client.fetch-registry=false
# EurekaServer的地址,现在是自己的地址,如果是集群,需要加上其它Server的地址
eureka.client.service-url.defaultZone:http://127.0.0.1:10001/eureka
- 新建模块,命名为eureka-provider03
目录结构如下图:
pom.xml:
<parent>
<groupId>com.wyj</groupId>
<artifactId>springcloud-eureka03</artifactId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<properties>
<java.version>1.8</java.version>
<spring-cloud.version>Finchley.SR1</spring-cloud.version>
</properties>
<dependencies>
<!-- springdatajpa -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<!-- springboot -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!-- mysql -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<!-- lombok -->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<!-- springcloud eureka client -->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
在启动器EurekaProvider03Application上添加注解用于开启eureka client
@SpringBootApplication
@EnableDiscoveryClient
public class EurekaProvider03Application{
public static void main(String[] args) {
SpringApplication.run(EurekaProvider03Application.class, args);
}
}
ProviderController:
@Controller
public class ProviderController {
@Autowired
private UserService userService;
@RequestMapping(value = "/findById/{id}")
@ResponseBody
public User findById(@PathVariable int id) {
User user = userService.findById(id);
return user;
}
}
UserService:
public interface UserService {
public User findById(int id);
}
UserServiceImpl:
@Service
public class UserServiceImpl implements UserService {
@Autowired
private UserRepository userRepository;
@Override
public User findById(int id) {
Optional<User> userOptional = userRepository.findById(id);
User user = userOptional.get();
return user;
}
}
UserRepository:
public interface UserRepository extends JpaRepository<User, Integer> {
}
User:
@Entity
@Data
public class User implements Serializable {
@Id
@GeneratedValue
private int id;
private String name;
private String sex;
private int age;
private String address;
private String phone;
}
application.properties:
注意:
这里eureka server的地址应该是多个,因为eureka server是集群
server.port=8081
### datasource ###
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/springcloud-eureka01?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8&useSSL=true
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.username=root
spring.datasource.password=root
### springdatajpa ###
#打印出自动生产的SQL,方便调试的时候查看
spring.jpa.show-sql=true
#更新数据库表结构
spring.jpa.hibernate.ddl-auto= update
#对打印的sql进行格式化,方便查看
spring.jpa.properties.hibernate.format_sql= true
spring.jpa.properties.hibernate.use_sql_comments=true
#指定生成表名的存储引擎为InneoDB
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL5InnoDBDialect
# springcloud
spring.application.name=eureka-provider
# EurekaServer地址,因为EurekaServer不止一个,因此注册服务的时候,EurekaServer地址,多个地址以','隔开
eureka.client.service-url.defaultZone=http://127.0.0.1:10000/eureka,http://127.0.0.1:10001/eureka
# 当调用getHostname获取实例的hostname时,返回ip而不是host名称
eureka.instance.prefer-ip-address=true
eureka.instance.ip-address=127.0.0.1
- 新建模块,命名为eureka-consumer03
目录结构如下图:
pom.xml:
<parent>
<groupId>com.wyj</groupId>
<artifactId>springcloud-eureka03</artifactId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<properties>
<java.version>1.8</java.version>
<spring-cloud.version>Finchley.SR1</spring-cloud.version>
</properties>
<dependencies>
<!-- springboot -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!-- lombok -->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<!-- springcloud eureka client -->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
在启动器EurekaConsumer03Application上添加注解用于开启eureka client
@SpringBootApplication
@EnableDiscoveryClient
public class EurekaConsumer03Application{
public static void main(String[] args) {
SpringApplication.run(EurekaConsumer03Application.class, args);
}
}
ConsumerController:
@Controller
public class ConsumerController{
@Autowired
private RestTemplate restTemplate;
// Eureka客户端,可以获取到服务实例信息
@Autowired
private DiscoveryClient discoveryClient;
@RequestMapping(value = "/findById/{id}")
@ResponseBody
public User findById(@PathVariable int id) {
// 根据服务名称,获取服务实例
List<ServiceInstance> instances = discoveryClient.getInstances("eureka-provider");
// 因为只有一个UserService,因此我们直接get(0)获取
ServiceInstance instance = instances.get(0);
String baseUrl = "http://" + instance.getHost() + ":" + instance.getPort();
System.out.println("baseUrl=" + baseUrl);
User user = restTemplate.getForObject(baseUrl + "/findById/" + id, User.class);
return user;
}
}
RestConfig:
@Configuration
public class RestConfig {
@Bean
public RestTemplate restTemplate() {
return new RestTemplate();
}
}
User:
@Data
public class User implements Serializable {
private int id;
private String name;
private String sex;
private int age;
private String address;
private String phone;
}
application.properties:
注意:
这里eureka server的地址应该是多个,因为eureka server是集群
server.port=8080
# springcloud
spring.application.name=eureka-consumer
# EurekaServer地址,因为EurekaServer不止一个,因此注册服务的时候,EurekaServer地址,多个地址以','隔开
eureka.client.service-url.defaultZone=http://127.0.0.1:10000/eureka,http://127.0.0.1:10001/eureka
# 当调用getHostname获取实例的hostname时,返回ip而不是host名称
eureka.instance.prefer-ip-address=true
测试使用
分别启动eureka-server03_1、eureka-server03_2、eureka-provider03和eureka-consumer03
注意:
两个server先启动的server会报错,如下图:
然后另外一台server启动后就不报错了,这是正确的,因为先启动的那台server不能找到另外一台形成集群,就报错了,当另外一台server启动时,找到了,就不报错了。
- 访问
浏览器访问http://127.0.0.1:8080/findById/1
-
访问eureka
http://127.0.0.1:10000/ (这里访问的是端口号为10000的server)访问http://127.0.0.1:10001/也是一样的
可以看到当前有eureka-consumer、eureka-provider两个实例和eureka-server形成的集群SpringCloud(四)eureka注册中心集群的使用