Spring Cloud微服务框架搭建

  最近开始学习Spring Cloud，主要借助翟永超的《Spring Cloud微服务实战》，书中使用的版本是Spring Cloud为Brixton.SR5版本，Spring Boot 1.3.7。

   当前Spring Cloud版本为Finchley RC1，Spring版本是2.1.0。很多依赖管理都发生了变化，看书的时候摸索了一点时间，所以记录下来。

Spring Cloud中文网，有中文文档

一、版本说明

jdk使用1.8.0

Spring Cloud：Finchley RC1

Spring Boot：2.1.0

下面为整个搭建的结构：

二、服务注册和发现模块（项目名称：w-eureka，使用端口号：8761）

1.使用Spring Boot提供的快捷搭建方式。

选择Eureka Server模块

2.pom.xml文件

        <parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.0.2.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>Finchley.BUILD-SNAPSHOT</spring-cloud.version>
	</properties>
	<dependencies>
		<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>
	<repositories>
		<repository>
			<id>spring-snapshots</id>
			<name>Spring Snapshots</name>
			<url>https://repo.spring.io/snapshot</url>
			<snapshots>
				<enabled>true</enabled>
			</snapshots>
		</repository>
		<repository>
			<id>spring-milestones</id>
			<name>Spring Milestones</name>
			<url>https://repo.spring.io/milestone</url>
			<snapshots>
				<enabled>false</enabled>
			</snapshots>
		</repository>
	</repositories>

3.配置application.properties

server.port=8761
eureka.instance.hostname=localhost
#是否自动注册自己
eureka.client.register-with-eureka=false
#如果是单点服务器就设置成false
eureka.client.fetch-registry=false
#注册中心地址
eureka.client.service-url.defaultZone=http://${eureka.instance.hostname}:${server.port}/eureka/

#关闭自我保护机制
eureka.server.enableSelfPreservation=false

4.启动EurekaServer（加上@EnableEurekaServer注解）

@EnableEurekaServer
@SpringBootApplication
public class WEurekaApplication {
	public static void main(String[] args) {
		SpringApplication.run(WEurekaApplication.class, args);
	}
}

访问localhost：8761，界面显示：

此时没有instance avaliable

三.服务提供者（项目名称：w-eurekaclient，使用端口号：8762和8763）

1.创建方式和server相同，选择Eureka Discovery、Web模块

2.pom.xml文件

        <parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.0.2.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>Finchley.BUILD-SNAPSHOT</spring-cloud.version>
	</properties>
	<dependencies>
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
		</dependency>
        <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>
	<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>
	<repositories>
		<repository>
			<id>spring-snapshots</id>
			<name>Spring Snapshots</name>
			<url>https://repo.spring.io/snapshot</url>
			<snapshots>
				<enabled>true</enabled>
			</snapshots>
		</repository>
		<repository>
			<id>spring-milestones</id>
			<name>Spring Milestones</name>
			<url>https://repo.spring.io/milestone</url>
			<snapshots>
				<enabled>false</enabled>
			</snapshots>
		</repository>
	</repositories>

3.配置application.properties

eureka.client.service-url.defaultZone=http://localhost:8761/eureka/
server.port=8762

#服务的名称
spring.application.name=service01

4.创建一个请求接口用于测试

@RestController
public class HelloController {
    @Value("${server.port}")
    private String port;

    @GetMapping("/hello")
    public String hello(@RequestParam String name){
        return "hello "+name+",i am from port:"+port;
    }
}

4.启动Client，启动程序上加上@EnableEurekaClient注释

@EnableEurekaClient
@SpringBootApplication
@RestController
public class WEurekaclientApplication {
	public static void main(String[] args) {
		SpringApplication.run(WEurekaclientApplication.class, args);
	}
}

此时server已经能够发现client上线的服务：service01

5.测试一下：

测试一下接口（http://localhost:8762/hi?name=sunwukong），

返回（hello suwukong,i am from port:8762），ok的话进入下一步。

四.服务消费者Feign（项目名称：w-feign，使用端口号：8764）

1.创建方式同上，选择Web，Feign，Eureka Discovery模块

2.pom.xml文件

        <parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.0.2.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>Finchley.BUILD-SNAPSHOT</spring-cloud.version>
	</properties>
	<dependencies>
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter-openfeign</artifactId>
		</dependency>
                <dependency>
                        <groupId>org.springframework.cloud</groupId>
                        <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
                </dependency>
                <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>
	<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>
	<repositories>
		<repository>
			<id>spring-snapshots</id>
			<name>Spring Snapshots</name>
			<url>https://repo.spring.io/snapshot</url>
			<snapshots>
				<enabled>true</enabled>
			</snapshots>
		</repository>
		<repository>
			<id>spring-milestones</id>
			<name>Spring Milestones</name>
			<url>https://repo.spring.io/milestone</url>
			<snapshots>
				<enabled>false</enabled>
			</snapshots>
		</repository>
	</repositories>

3.配置application.properties

eureka.client.service-url.defaultZone=http://localhost:8761/eureka/
server.port=8764
spring.application.name=feign

4.创建Feign接口(“/hello”为service01服务的接口，value=name为service01服务接口参数的名称)

@FeignClient(value = "service01")
public interface SchedualServiceHello {
    @RequestMapping(value="/hello",method = RequestMethod.GET)
    String sayHiFromClientOne(@RequestParam (value="name") String name);
}

5.创建API接口

@RestController
public class HiController {
    @Autowired
    private SchedualServiceHello schedualServiceHello;

    @RequestMapping(value="/hi",method= RequestMethod.GET)
    public String sayHi(@RequestParam String name ){
        return schedualServiceHello.sayHiFromClientOne(name);
    }

}

6.将eurekaclient服务启动2次，端口分别为8762，8763，

方法是在启动配置的Program arguments参数上修改端口参数：--server.port=8763

7.启动应用，加入@EnableDiscoveryClient，@EnableFeignClients注解

@EnableFeignClients
@EnableDiscoveryClient
@SpringBootApplication
public class WFeignApplication {
	public static void main(String[] args) {
		SpringApplication.run(WFeignApplication.class, args);
	}
}

8.测试结果

多次访问http://lcoalhost:8764/hi?name=sunwukong，浏览器交替显示

hi sunwokong,i am from port :8762

hi sunwokong,i am from port :8763

五.服务消费者Ribbon（项目名称：w-ribbon，使用端口号：8765）

1.创建方式同上，选择Web，Ribbon，Eureka Discovery模块

2.pom.xml文件

<parent>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-parent</artifactId>
   <version>2.0.2.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>Finchley.BUILD-SNAPSHOT</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-ribbon</artifactId>
   </dependency>
       <dependency>
           <groupId>org.springframework.cloud</groupId>
           <artifactId>spring-cloud-starter-netflix-eureka-client</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>
<repositories>
   <repository>
      <id>spring-snapshots</id>
      <name>Spring Snapshots</name>
      <url>https://repo.spring.io/snapshot</url>
      <snapshots>
         <enabled>true</enabled>
      </snapshots>
   </repository>
   <repository>
      <id>spring-milestones</id>
      <name>Spring Milestones</name>
      <url>https://repo.spring.io/milestone</url>
      <snapshots>
         <enabled>false</enabled>
      </snapshots>
   </repository>
</repositories>

3.配置application.properties

eureka.client.service-url.defaultZone=http://localhost:8761/eureka/
server.port=8765
spring.application.name=ribbon

4.增加RestTemplate的BEAN到容器中，为了方便放在主函数中，主函数添加@EnableDiscoveryClient和@EnableEurekaClient注解

@EnableDiscoveryClient
@EnableEurekaClient
@SpringBootApplication
public class WRibbonApplication {
    @Bean
    @LoadBalanced
    RestTemplate getRestTemplate(){
        return new RestTemplate();
    }

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

5.创建访问接口

@RestController
public class rHelloController {
    @Autowired
    RestTemplate restTemplate;

    @RequestMapping(value="/hi",method = RequestMethod.GET)
    public String rSayHello(@RequestParam String name){
        return restTemplate.getForEntity("http://service01/hello?name="+name,String.class).getBody();
    }
}

6.启动测试

多次访问http://lcoalhost:8765/hi?name=sunwukong，浏览器交替显示

hi sunwokong,i am from port :8762

hi sunwokong,i am from port :8763

六.Hystrix断路器

    目的就是防止服务中发生雪崩，服务中某一个服务发生阻塞，引起其他服务等待的情况。如果多个服务发生阻塞，那么整个项目都会受到影响。

1.配置Hystrix，在前面创建的w-ribbon的pom.xml文件中，加入Hystrix依赖

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

2.在测试接口上增加 @HystrixCommand(fallbackMethod = "hiError")注解，

    其中hiError为阻塞后回滚的方法，定义回滚方法hiError。

@RestController
public class rHelloController {
    @Autowired
    RestTemplate restTemplate;
    @RequestMapping(value="/hi",method = RequestMethod.GET)
    @HystrixCommand(fallbackMethod = "hiError")
    public String rSayHello(@RequestParam String name){
        return restTemplate.getForEntity("http://service01/hello?name="+name,String.class).getBody();
    }
    public String hiError(String name){
        return "hi,"+name+",sorry a ! error!";
    }
}

5.在主函数上加上@EnableHystrix启动Hystrix组件

@EnableDiscoveryClient
@EnableEurekaClient
@SpringBootApplication
@EnableHystrix
public class WRibbonApplication {
    @Bean
    @LoadBalanced
    RestTemplate getRestTemplate(){
        return new RestTemplate();
    }

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

6.测试。停止eurekaclient提供的8762，8763端口的服务。
访问http://lcoalhost:8765/hi?name=sunwukong，

测试通过。