SpringCloud 学习笔记
一、搭建微服务环境
1. 创建父模块(SpringCloud_demo)
1.1 导入坐标
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-logging</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.4</version>
<scope>provided</scope>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>Greenwich.RELEASE</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<repositories>
<repository>
<id>spring-snapshots</id>
<name>Spring Snapshots</name>
<url>http://repo.spring.io/libs-snapshot-local</url>
<snapshots>
<enabled>true</enabled>
</snapshots>
</repository>
<repository>
<id>spring-milestones</id>
<name>Spring Milestones</name>
<url>http://repo.spring.io/libs-milestone-local</url>
<snapshots>
<enabled>false</enabled>
</snapshots>
</repository>
<repository>
<id>spring-releases</id>
<name>Spring Releases</name>
<url>http://repo.spring.io/libs-release-local</url>
<snapshots>
<enabled>false</enabled>
</snapshots>
</repository>
</repositories>
<pluginRepositories>
<pluginRepository>
<id>spring-snapshots</id>
<name>Spring Snapshots</name>
<url>http://repo.spring.io/libs-snapshot-local</url>
<snapshots>
<enabled>true</enabled>
</snapshots>
</pluginRepository>
<pluginRepository>
<id>spring-milestones</id>
<name>Spring Milestones</name>
<url>http://repo.spring.io/libs-milestone-local</url>
<snapshots>
<enabled>false</enabled>
</snapshots>
</pluginRepository>
</pluginRepositories>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>2. 创建子模块(product_server,order_server)
2.1 引入子模块坐标
<dependencies>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.32</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
</dependencies>2.2 编写子模块application.yml 配置文件
server:
port: 9001
spring:
application:
name: service-product
datasource:
driver-class-name: com.mysql.jdbc.Driver
url: jdbc:mysql://localhost:3306/netdisk?useUnicode=true&characterEncoding=utf8
username: root
password:
jpa:
database: MySQL
show-sql: true
open-in-view: true2.3 编写子模块启动类
@SpringBootApplication
public class EurekaServerApplication {
public static void main(String[] args) {
SpringApplication.run(EurekaServerApplication.class, args);
}
}3. 创建子模块注册机（eureka_server）
3.1 导入坐标
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
</dependency>
</dependencies>3.2 编写application.yml
server:
port: 9000
# 配置 eureka server
eureka:
instance:
hostname: localhost
client:
register-with-eureka: false # 是否将自己注册到注册中心
fetch-registry: false # 是否要从eureka中获取信息
# 配置暴露给Eureka Client的请求地址
service-url:
defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/3.3 编写启动类
@SpringBootApplication
@EnableEurekaServer
public class EurekaServerApplication {
public static void main(String[] args) {
SpringApplication.run(EurekaServerApplication.class, args);
}
}4. 将服务提供者注册到eureka_server上
4.1 导入坐标
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>4.2 application.yml中添加Eureka的配置
# 配置 Eureka
eureka:
client:
service-url:
defaultZone: http://localhost:9000/eureka/
instance:
prefer-ip-address: true # 使用ip地址注册4.3 启动类添加注解@EnableDiscoveryClient（可选）
@SpringBootApplication
@EntityScan("com/gfy/eureka/entity")
@EnableDiscoveryClient
public class ProductApplication {
public static void main(String[] args) {
SpringApplication.run(ProductApplication.class, args);
}
}5. 服务调用者
5.1 编写启动类
@RestController
@RequestMapping("order")
public class OrderController {
@Autowired
private RestTemplate restTemplate;
@GetMapping("{id}")
public Product findById(@PathVariable Long id){
Product product = restTemplate.getForObject("http://localhost:9001/product/1", Product.class);
return product;
}
}5.2 编写服务调用者(order_server) 的controller
@Autowired
private RestTemplate restTemplate;
@Autowired
private DiscoveryClient discoveryClient;
@GetMapping("{id}")
public Product findById(@PathVariable Long id){
List<ServiceInstance> instances = discoveryClient.getInstances("service-product");
ServiceInstance serviceInstance = instances.get(0);
Product product = restTemplate.getForObject("http://"+serviceInstance.getHost()+":"+ serviceInstance.getPort() +"/product/1", Product.class);
return product;
}
===============================================
Eureka细节
在Eureka控制台显示服务IP
# 配置 Eureka
eureka:
client:
service-url:
defaultZone: http://localhost:9000/eureka/
instance:
prefer-ip-address: true # 使用ip地址注册
instance-ip: ${spring.cloud.client.ip-address}:${server.port} #向注册中心中注入服务IPEureka 自我保护机制
统计所有服务接收率，若在阈值以下，则不会剔除注册的服务
server:
enable-self-preservation: false # 自我保护
eviction-interval-timer-in-ms: 4000 # 剔除服务间隔Ribbon 负载均衡策略
1. 服务调用
eureka内部继承了rbbon
1.1 创建RestTemplate的时候，声明@LoadBalanced
2.2 使用restTemplate调用远程微服务：不再需要拼接微服务的URL，以待请求的服务名替换IP地址
2. 原理：
2.1 服务端负载均衡：ngnix F5
com.netflix.loadbalancer包下 RoundRobinRule(轮询)、RandomRule(随机)、RetryRule(重试)、WeightedResponseTimeRule(权重)等策略
2.2 修改负载策略
#修改ribbon负载均衡策略 服务名:ribbon:NFLoadBalancerRuleClassName:策略全类名
service-product:
ribbon:
NFLoadBalancerRuleClassName: com.netflix.loadbalancer.RandomRule
浙公网安备 33010602011771号