sptingcloud官方文档
https://spring.io/projects/spring-cloud
springcloud中文文档
https://springcloud.cc/spring-cloud-dalston.html
一、搭建基础springcloud |
二、服务发现:Eureka服务器 |
三、客户端负载均衡:ribbon |
四、应用通信:feign |
一、搭建基础springcloud
由于springcloud是基于http的所以它不用将接口提取出来建立一个容器
父工程
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>org.besteam</groupId>
<artifactId>besteamcloud</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>pom</packaging>
<properties>
<dept-api.version>1.0-SNAPSHOT</dept-api.version>
<lombok.version>1.16.18</lombok.version>
<junit.version>4.12</junit.version>
<log4j.version>1.2.17</log4j.version>
<lombok.version>1.16.18</lombok.version>
</properties>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>Dalston.SR1</version>
<type>pom</type>
<scope>import</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-dependencies</artifactId>
<version>1.5.9.RELEASE</version>
<type>pom</type>
<scope>import</scope>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.0.4</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.0.31</version>
</dependency>
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>3.0.5</version>
</dependency>
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-core</artifactId>
<version>1.2.3</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>${junit.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>${log4j.version}</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.53</version>
</dependency>
</dependencies>
</dependencyManagement>
<modules>
<module>dept-api</module>
<module>dept-provider</module>
<module>dept-consumer</module>
</modules>
</project>
项目名:dept-api
核心内容:
/**
* @author ginwu
* @date 2019/1/19 10:22
* @description
*/
@NoArgsConstructor
@AllArgsConstructor
@Data
@Accessors(chain=true)
@TableName(value = "dept")
public class Dept {
@TableId(type = IdType.AUTO)
private Long id;
private String deptName;
private String parentName;
private Integer sort;
private Date createTime;
}
提供方
项目名:dept-provider
核心内容:
<!-- 引用dept-api -->
<dependency>
<groupId>org.besteam</groupId>
<artifactId>dept-api</artifactId>
<version>${dept-api.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-config</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
package org.besteam.controller;
import org.besteam.entity.Dept;
import org.besteam.service.DeptService;
import org.springframework.beans.factory.annotation.Autowired;
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 java.util.List;
/**
* @author ginwu
* @date 2019/1/19 10:31
* @description
*/
@RestController
public class DeptController {
@Autowired
private DeptService deptService;
/**
* 通过id查询部门
* @param id
* @return
*/
@RequestMapping(value = "/dept/get/{id}",method = RequestMethod.GET)
public Dept getDept(@PathVariable("id") Long id){
return deptService.getDeptById(id);
}
@RequestMapping(value = "/dept/all")
public List<Dept> getDeptList(){
return deptService.selectAll();
}
@RequestMapping(value = "/dept/add",method = RequestMethod.POST)
public void add(Dept dept){
deptService.add(dept);
}
@RequestMapping(value = "/dept/update")
public void update(Dept dept){
deptService.update(dept);
}
}
yml
server:
port: 8081
spring:
application:
name: dept-provider
datasource:
type: com.alibaba.druid.pool.DruidDataSource
driver-class-name: com.mysql.jdbc.Driver
url: jdbc:mysql://localhost:3306/besteamcloud
username: root
password: 123123
initial-size: 1
min-idle: 1
max-active: 20
test-on-borrow: true
mybatis-plus:
mapper-locations:
- class*:mapper/**/*Mapper.xml
消费方:
项目名:consumer-dept
核心内容:
/**
* @author ginwu
* @date 2019/1/19 16:50
* @description
*/
@RestController
@RequestMapping("/consumer/dept")
public class DeptConsumerController {
//单机测直接访问本地即可
//@1
private static final String REST_URL_PREFIX = "http://localhost:8081";
//@3
private static String REST_URL_LOADBALANCE = "http://DEPT-PROVIDER";
@Autowired
private RestTemplate restTemplate;
//@2
@Autowired
private LoadBalancerClient loadBalancerClient;
@RequestMapping("/get/{id}")
public String getDeptById(@PathVariable("id") Long id){
//第一种访问方式@1
Dept dept = restTemplate.getForObject(REST_URL_PREFIX+"/dept/get/"+id,Dept.class);
//第二种访问方式@2
// ServiceInstance serviceInstance = loadBalancerClient.choose("BESTEAMCLOUD-PROVIDER8081");
// String url = String.format("http://%s:%s",serviceInstance.getHost(),serviceInstance.getPort());
// Dept dept = restTemplate.getForObject(url+"/dept/get/"+id,Dept.class);
//
//第三种访问方式@3
//在config中的RestTemplate中添加@LoadBalaced
// Dept dept = restTemplate.getForObject(REST_URL_LOADBALANCE+"/dept/get/"+id,Dept.class);
return JSON.toJSONString(dept);
}
@RequestMapping("/all")
public String getAll(){
List<Dept> list = restTemplate.getForObject(REST_URL_PREFIX+"/dept/all",List.class);
return JSON.toJSONString(list);
}
}
package org.besteam.config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.client.RestTemplate;
/**
* @author ginwu
* @date 2019/1/19 17:34
* @description
*/
@Configuration
public class CloudConfig {
@Bean
// @LoadBalanced
public RestTemplate getRestTemplate(){
return new RestTemplate();
}
}
yml
server:
port: 80
至此,一个基本的远程调用模块就已经完成了,接下带就是各种配置各种部署了
二、服务发现:Eureka服务器
eureka的概念在官网中已有说明,这里不再说明,只给句具体的实现和粗略的讲解:
注册、发现:就是把我们已经实现好的功能模块暴露给eureka,然后通过eureka去控制用户具体访问那个节点的模块,怎样去负载均衡等。
注册、发现服务:
项目名:besteam-eureka
核心内容:
<!-- eureka 服务端 -->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-eureka-server</artifactId>
</dependency>
<!-- eureka Finchley版本 -->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
</dependency>
@SpringBootApplication
@EnableEurekaServer // EurekaServer服务器端启动类,接受其它微服务注册进来
public class DeptEurekaApplication {
public static void main(String[] args) {
SpringApplication.run(DeptEurekaApplication.class, args);
}
}
server:
port: 7001
eureka:
instance:
hostname: besteamEureka7001.com #eureka服务端的实例名称
client:
register-with-eureka: false #false表示不向注册中心注册自己。
fetch-registry: false #false表示自己端就是注册中心,我的职责就是维护服务实例,并不需要去检索服务
service-url:
defaultZone: http://localhost:7001/eureka/ #设置与Eureka Server交互的地址查询服务和注册服务都需要依赖这个地址。
# defaultZone: http://localhost:7002/eureka/,defaultZone: http://localhost:7003/eureka/
另外需要将其他的微服务注册进来就需要在微服务中进行配置
项目名:besteam-eureka
核心内容:
<!-- 将consumer注册到eureka -->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-eureka</artifactId>
</dependency>
<!-- eureka Finchley版本 -->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
@SpringBootApplication
@EnableEurekaClient //注册到eureka服务
public class DeptProviderApplication {
public static void main(String[] args) {
SpringApplication.run(DeptConsumerApplication.class, args);
}
}
server:
port: 8081
spring:
application:
name: dept-provider
eureka:
instance:
instance-id: besteamcloud-provider8081
prefer-ip-address: true #访问路径可以显示IP地址
client:
service-url:
defaultZone: http://localhost:7001/eureka #注册到eureka
三、客户端负载均衡:ribbon
之所以为客户端的负载均衡是因为它是为消费者所提供的,意思是所有的消费者都在注册中心列表中,当消费者需要访问时,注册中心会把相应服务的注册列表给客户端,有客户端去选择调用哪一个服务。而正对服务端的负载均衡就需要一个代理,有客户端提出访问,然后通过代理去找服务端,常见的服务端负载均衡Nginx、dubbo
ribbon实现的负载均衡有三点:
- 服务发现
- 服务选择规则
- 服务监听
核心内容:
package org.besteam.controller;
import com.alibaba.fastjson.JSON;
import org.besteam.entity.Dept;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;
import java.util.List;
/**
* @author ginwu
* @date 2019/1/19 16:50
* @description
*/
@RestController
@RequestMapping("/consumer/dept")
public class DeptConsumerController {
//单机测直接访问本地即可
//@1
private static final String REST_URL_PREFIX = "http://localhost:8081";
//@3
private static String REST_URL_LOADBALANCE = "http://DEPT-PROVIDER";
@Autowired
private RestTemplate restTemplate;
//@2
@Autowired
private LoadBalancerClient loadBalancerClient;
@RequestMapping("/get/{id}")
public String getDeptById(@PathVariable("id") Long id){
//第一种访问方式@1
// Dept dept = restTemplate.getForObject(REST_URL_PREFIX+"/dept/get/"+id,Dept.class);
//第二种访问方式@2
// ServiceInstance serviceInstance = loadBalancerClient.choose("BESTEAMCLOUD-PROVIDER8081");
// String url = String.format("http://%s:%s",serviceInstance.getHost(),serviceInstance.getPort());
// Dept dept = restTemplate.getForObject(url+"/dept/get/"+id,Dept.class);
//
//第三种访问方式@3
//在config中的RestTemplate中添加@LoadBalaced
Dept dept = restTemplate.getForObject(REST_URL_LOADBALANCE+"/dept/get/"+id,Dept.class);
return JSON.toJSONString(dept);
}
@RequestMapping("/all")
public String getAll(){
List<Dept> list = restTemplate.getForObject(REST_URL_PREFIX+"/dept/all",List.class);
return JSON.toJSONString(list);
}
}
package org.besteam.config;
import com.netflix.loadbalancer.IRule;
import com.netflix.loadbalancer.RandomRule;
import org.apache.tomcat.util.digester.Rule;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.client.RestTemplate;
/**
* @author ginwu
* @date 2019/1/19 17:34
* @description
*/
@Configuration
public class CloudConfig {
@Bean
@LoadBalanced
public RestTemplate getRestTemplate(){
return new RestTemplate();
}
/**
* 自定义访问规则,默认为轮询访问
* ,此方法为随机访问
* @return
*/
@Bean
public IRule iRule(){
return new RandomRule();
}
}
常用的几种访问规则有:
-
简单轮询负载均衡(RoundRobin)
以轮询的方式依次将请求调度不同的服务器,即每次调度执行i = (i + 1) mod n,并选出第i台服务器。 -
随机负载均衡 (Random)
随机选择状态为UP的Server -
加权响应时间负载均衡 (WeightedResponseTime)
根据相应时间分配一个weight,相应时间越长,weight越小,被选中的可能性越低。 -
区域感知轮询负载均衡(ZoneAvoidanceRule)
复合判断server所在区域的性能和server的可用性选择server
Ribbon自带负载均衡策略比较
策略名 | 策略声明 | 策略描述 |
---|---|---|
BestAvailableRule | public class BestAvailableRule extends ClientConfigEnabledRoundRobinRule | 选择一个最小的并发请求的server |
AvailabilityFilteringRule | public class AvailabilityFilteringRule extends PredicateBasedRule | 过滤掉那些因为一直连接失败的被标记为circuit tripped的后端server,并过滤掉那些高并发的的后端server(active connections 超过配置的阈值) |
WeightedResponseTimeRule | public class WeightedResponseTimeRule extends RoundRobinRule | 根据相应时间分配一个weight,相应时间越长,weight越小,被选中的可能性越低。 |
RetryRule | public class RetryRule extends AbstractLoadBalancerRule | 对选定的负载均衡策略机上重试机制。 |
RoundRobinRule | public class RoundRobinRule extends AbstractLoadBalancerRule | roundRobin方式轮询选择server |
RandomRule | public class RandomRule extends AbstractLoadBalancerRule | 随机选择一个server |
ZoneAvoidanceRule | public class ZoneAvoidanceRule extends PredicateBasedRule | 复合判断server所在区域的性能和server的可用性选择server |
四、应用通信:feign
项目名:besteam-consumerfeign是一个类似于伪RPC的应用之间的调用组件,实际上还是基于rest方式实现的,它的功能和ribbon类似,但它是以声明式的方式在客户端实现的
修改/添加内容:
<!-- feign -->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-feign</artifactId>
</dependency>
<!-- feign Finchley版本 -->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-openfeign</artifactId>
</dependency>
package org.besteam.client;
import org.springframework.cloud.netflix.feign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;
/**
* @author ginwu
* @date 2019/1/23 20:33
* @description]
* 创建一个接口调用DEPT-PROVIDER服务中实现的方法
*/
@FeignClient(value = "DEPT-PROVIDER")
public interface InnerFeignClient {
@GetMapping("/feign/get")
public String feignTest();
}
package org.besteam.service;
import org.besteam.client.InnerFeignClient;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
/**
* @author ginwu
* @date 2019/1/23 20:40
* @description
* 实现调用feign远程调用的方法
*/
@Service
public class FeignTestService {
@Autowired
private InnerFeignClient innerFeignClient;
public String foo(){
String res = innerFeignClient.feignTest();
if(null == res||"".equals(res)){
return "test failure!!!";
}
return res;
}
}
启动类添加@EnableFeignClients声明使用feign
@SpringBootApplication
@EnableEurekaClient //注册到eureka服务
@EnableFeignClients //声明feign
public class DeptConsumerApplication {
public static void main(String[] args) {
SpringApplication.run(DeptConsumerApplication.class, args);
}
}
项目名:besteam-consumer修改/添加内容:
按照正常些接口的方式实现
注意:到这里会发现,消费端调用服务端的接口,却要服务端去实现消费端需要暴露的接口,这显然不服务解耦合的思想,这个时候就需要把服务端的接口当做一个模块给暴露出来,或者在消费端中自己实现一个接口给暴露出来
实现方法如下:
新建模块provider-api
核心内容:
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-feign</artifactId>
</dependency>
<!-- feign Finchley版本 -->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-openfeign</artifactId>
</dependency>
package org.besteam.client;
import org.springframework.cloud.netflix.feign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;
/**
* @author ginwu
* @date 2019/1/23 20:33
* @description]
* 创建一个接口调用DEPT-PROVIDER服务中实现的方法
*/
@FeignClient(value = "DEPT-PROVIDER")
public interface InnerFeignClient {
@GetMapping("/feign/get")
public String feignTest();
}
这样我们就把消费方需要提供的接口给暴露出来了,就像rpc的做法一样,但是怎样才能让消费者方去扫描到这个接口呢?实现方式只需要在启动类的@EnableFeignClients上加一个包扫描:
项目名: besteam-consumer
修改/添加内容:
@SpringBootApplication
@EnableEurekaClient //注册到eureka服务
@EnableFeignClients(basePackages= {"org.besteam.client"}) //声明feign
public class DeptConsumerApplication {
public static void main(String[] args) {
SpringApplication.run(DeptConsumerApplication.class, args);
}
}