springcloud基础入门

先了解一下springcloud和dubbo的区别

dubbo由于是二进制的传输，占用带宽会更少

springCloud是http协议传输，带宽会比较多，同时使用http协议一般会使用JSON报文，消耗会更大

dubbo的开发难度较大，原因是dubbo的jar包依赖问题很多大型工程无法解决

springcloud的接口协议约定比较自由且松散，需要有强有力的行政措施来限制接口无序升级

dubbo的注册中心可以选择zk,redis等多种，springcloud的注册中心只能用eureka或者自研

springcloud的最大的特点是可以很好的和restful模式进行交互

dubbo是基于rpc的

在开始SpringCloud之前，先看一下一个简单的服务提供者和服务消费者。服务提供者提供一个REST风格的HTTP接口给服务消费者。

1.1 普通的提供者

1.1.1 pom.xml

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.5.13.RELEASE</version>
    <relativePath/>
</parent>

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    <java.version>1.8</java.version>
</properties>

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </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>

1.1.1 关键代码

package com.test.springcloud.provider.pojo;

public class User {
    private Long id;
    private String username;
    //getter/setter略

}

Controller

package com.test.springcloud.provider.controller;

import com.test.springcloud.provider.pojo.User;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class UserController {
    @GetMapping("/simple/{id}")//rest 风格,微服务一般都使用 rest 风格
    public User findById(@PathVariable Long id) {
        User user=new User();
        user.setId(id);
        user.setUsername("hello "+id);
        return user;
    }

1.1.1 application.yml

server:
port: 8081

1.1 普通的消费者

1.1.1 pom.xml

parent>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-parent</artifactId>
   <version>1.5.13.RELEASE</version>
   <relativePath/> <!-- lookup parent from repository -->
</parent>

<properties>
   <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
   <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
   <java.version>1.8</java.version>
</properties>
<dependencies>
   <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
   </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>

实体类：

package com.test.springcloud.consumer.pojo;

public class User {
    private Long id;
    private String username;
    //getter/setter略
}

Controller

package com.test.springcloud.consumer.controller;

import com.test.springcloud.consumer.pojo.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;

@RestController
public class UserController {
    @Autowired
    private RestTemplate restTemplate;// rest 请求模板类

    @Value("${user.userServicePath}")//从配置文件中读取指定属性,名字和配置中保持一致即可
    private String userServicePath;

    @GetMapping("/user/{id}")
    public User findById(@PathVariable Long id) {
        //调用指定的地址,传递参数过去,将返回的数据解析为 user 格式
        // return this.restTemplate.getForObject("http://localhost:7900/simple/"+ id, User.class);//硬编码,不好
        return this.restTemplate.getForObject(this.userServicePath + id, User.class);//通过配置文件注入地址的方式
    }
}

启动类

package com.test.springcloud.consumer;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;

@SpringBootApplication
public class SpringcloudTestConsumerApplication {
   @Bean
   public RestTemplate restTemplate() {
      return new RestTemplate();
   }
   public static void main(String[] args) {
      SpringApplication.run(SpringcloudTestConsumerApplication.class, args);
   }
}

1.1.1 application.yml

server:
  port: 8082
userPath: http://localhost:8080/user/

1.1 Eureka

在消费者调用服务的时候，服务提供者的地址是以硬编码的形式写在配置文件中的。如果服务端迁移就需要改变地址。我们可以将服务注册到Eureka，消费者不必关心提供者的真实地址，通过Eureka中的服务名直

<parent>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-parent</artifactId>
   <version>1.5.13.RELEASE</version>
   <relativePath/>
</parent>

<properties>
   <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
   <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
   <java.version>1.8</java.version>
   <spring-cloud.version>Edgware.SR2</spring-cloud.version>
</properties>

<dependencies>
   <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
   </dependency>
   <dependency>
      <groupId>org.springframework.cloud</groupId>
      <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
   </dependency>

   <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-test</artifactId>
      <scope>test</scope>
   </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>

<build>
   <plugins>
      <plugin>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-maven-plugin</artifactId>
      </plugin>
   </plugins>
</build>

接调用服务即可。

1.1.1 启动类

在启动类上增加@EnableEurekaServer注解

server:
  port: 8083

eureka:
  instance:
    hostname: localhost
  client:
    serviceUrl:
      defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/

启动8083端口访问

能看见一个管理的后台

1.1.1 修改服务提供者

pom.xml中添加SpringCloud的引用

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-dependencies</artifactId>
            <version>Edgware.SR2</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>
<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-eureka</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
</dependencies>

启动类上添加注解@EnableEurekaClient：

yml配置文件

server:
  port: 8081
eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8083/eureka/
spring:
  application:
    name: service-provider  #这个名字就是调用服务时的名字

1.1.1 修改消费者

pom.xml同提供者一样

启动类添加注解@EnableEurekaClient还有restTemplate上的@LoadBalanced

完整的application.yml

erver:
  port: 8082
user: #此处 user没有任何含义,主要是一个名字而已
  #即便在这里也类似于硬编码, 还是不够灵活,定义提供者的位置
  #userServicePath: http://localhost:8081/simple/
  userServicePath: http://SERVICE-PROVIDER/simple/
eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8083/eureka/
spring:
  application:
    name: service-comsumer

1.1 ribbon负载均衡

在消费者中添加依赖：

<dependency>
   <groupId>org.springframework.cloud</groupId>
   <artifactId>spring-cloud-starter-ribbon</artifactId>
</dependency>

启动两次提供者(一个运行main方法，一个maven启动)，修改端口，模拟同一个服务部署在不同的服务器上，如端口为8084。稍稍修改一些controller中的代码，区分两个服务：

然后访问

1. Feign

Feign是一个声明式的伪Http客户端，它使得写Http客户端变得更简单。使用Feign，只需要创建一个接口并注解。Feign默认集成了Ribbon，并和Eureka结合，默认实现了负载均衡的效果。

<parent>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-parent</artifactId>
   <version>1.5.13.RELEASE</version>
   <relativePath/> <!-- lookup parent from repository -->
</parent>

<properties>
   <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
   <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
   <java.version>1.8</java.version>
   <spring-cloud.version>Edgware.SR2</spring-cloud.version>
</properties>

<dependencies>
   <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
   </dependency>
   <dependency>
      <groupId>org.springframework.cloud</groupId>
      <artifactId>spring-cloud-starter-eureka</artifactId>
   </dependency>
   <dependency>
      <groupId>org.springframework.cloud</groupId>
      <artifactId>spring-cloud-starter-feign</artifactId>
   </dependency>
   <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-test</artifactId>
      <scope>test</scope>
   </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>

<build>
   <plugins>
      <plugin>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-maven-plugin</artifactId>
      </plugin>
   </plugins>
</build>

启动类添加@EnableEurekaClient注解和@EnableFeignClients

1.1 service

package com.test.springcloud.feign.consumer.service;

import com.test.springcloud.feign.consumer.pojo.User;
import org.springframework.cloud.netflix.feign.FeignClient;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

@FeignClient(value = "SERVICE-PROVIDER")
public interface UserService {
    @RequestMapping(value = "/simple/{id}", method = RequestMethod.GET)
    User getUserById(@PathVariable(value = "id") Long id);
}

@FeignClient的值是服务提供者在Eureka上的名字。

方法上@RequestMapping的值是请求服务提供者时的路径。参数的传递方式和SpringMVC的Controller接收参数时语法一样，如@PathVariable,@RequestParam

User类同服务提供者中的一样。

1.1 Controller

package com.test.springcloud.feign.consumer.controller;

import com.test.springcloud.feign.consumer.pojo.User;
import com.test.springcloud.feign.consumer.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class UserController {
    @Autowired
    private UserService userService;

    @RequestMapping(value = "/test", method = RequestMethod.GET)
    public User sayHi(@RequestParam Long id) {
        return userService.getUserById(id);
    }
}

1.1 application.yml

eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8083/eureka/
server:
  port: 8085
spring:
  application:
    name: service-feign

1. 断路器Hystrix

1.1 Ribbon使用断路器

在ribbon的消费者工程中加入断路器依赖：

<dependency>
   <groupId>org.springframework.cloud</groupId>
   <artifactId>spring-cloud-starter-hystrix</artifactId>
</dependency>

启动类上添加注解@EnableHystrix

启动项目，在服务提供者挂掉的时候，会看到提示信息：

如果不做熔断，会在请求服务提供者超时之后报错：

1.2Feign使用熔断器

在yml配置文件增默认自带熔断器打开

feign:
  hystrix:
    enabled: true

在消费的service层修改

@FeignClient(value = "SERVICE-PROVIDER", fallback = TestServiceFallback.class)
public interface TestService {
    @RequestMapping(value = "/user/{id}", method = RequestMethod.GET)
    User getUserById(@PathVariable(value = "id") Integer id);

}

创建TestService的实现类TestServiceFallback

@Component
public class TestServiceFallback implements TestService {
    @Override
    public User getUserById(Integer id) {
        User user = new User();
        user.setId(-2);
        user.setName("server error2");
        return user;
    }

1.3 Hystrix Dashboard (Hystrix 仪表盘)

在pom中添加依赖(feign和robbin）

<dependency>
   <groupId>org.springframework.cloud</groupId>
   <artifactId>spring-cloud-starter-hystrix</artifactId>
</dependency>
<dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
   <groupId>org.springframework.cloud</groupId>
   <artifactId>spring-cloud-starter-hystrix-dashboard</artifactId>
</dependency>

再启动类加

@EnableHystrix
@EnableHystrixDashboard注解

启动访问localhost:port/hystrix

访问服务的提供者能看到这个界面可以清晰的看到这个请求的成功率和失败率

1. 路由Zuul

新建工程pom配置

<parent>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-parent</artifactId>
   <version>1.5.13.RELEASE</version>
   <relativePath/> <!-- lookup parent from repository -->
</parent>

<properties>
   <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
   <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
   <java.version>1.8</java.version>
   <spring-cloud.version>Edgware.SR3</spring-cloud.version>
</properties>

<dependencies>
   <dependency>
      <groupId>org.springframework.cloud</groupId>
      <artifactId>spring-cloud-starter-eureka</artifactId>
   </dependency>
   <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
   </dependency>
   <dependency>
      <groupId>org.springframework.cloud</groupId>
      <artifactId>spring-cloud-starter-zuul</artifactId>
   </dependency>
   <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-test</artifactId>
      <scope>test</scope>
   </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>

<build>
   <plugins>
      <plugin>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-maven-plugin</artifactId>
      </plugin>
   </plugins>
</build>

yml文件的配置

eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8083/eureka/
server:
  port: 8086
spring:
  application:
    name: service-zuul
zuul:
  routes:
    api-a:
      path: /api-a /**
      serviceId: service-consumer
    api-b:
      path: /api-b /**
      serviceId: service-feign

routes定义了请求转发的规则。path是url访问路径，serviceId是对应的Eureka中的服务

http://localhost:8086/api-a/user/1会发送到service-consumer对应的工程

http://localhost:8086/api-b/test?id=2会发送到feign的工程

启动类：

@SpringBootApplication
@EnableEurekaClient
@EnableZuulProxy
public class Zuul0723Application {

    public static void main(String[] args) {
        SpringApplication.run(Zuul0723Application.class, args);
    }
}

posted @ 2018-09-12 21:16 BlackCatFish 阅读(424) 评论(0) 编辑收藏举报

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springcloud基础入门

1.1 普通的提供者

1.1.1 pom.xml

1.1.1 关键代码

1.1.1 application.yml

1.1 普通的消费者

1.1.1 pom.xml

1.1.1 application.yml

1.1 Eureka

1.1.1 启动类

1.1.1 修改服务提供者

1.1.1 修改消费者

1.1 ribbon负载均衡

1. Feign

1.1 service

1.1 Controller

1.1 application.yml

1. 断路器Hystrix

1.1 Ribbon使用断路器

1.2Feign使用熔断器

1.3 Hystrix Dashboard (Hystrix 仪表盘)

1. 路由Zuul

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