SpringCloud(二)——搭建Eureka集群

集群架构图

创建Eureka服务器，并启动两个实例，并且两个实例相互注册

添加依赖

<?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>com.zgy</groupId>
	<artifactId>cloud-114</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>cloud-114</name>
	<description>Demo project for Spring Boot</description>

	<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>

	<dependencyManagement>
		<dependencies>
			<dependency>
				<groupId>org.springframework.cloud</groupId>
				<artifactId>spring-cloud-dependencies</artifactId>
				<version>Dalston.SR5</version>
				<type>pom</type>
				<scope>import</scope>
			</dependency>
		</dependencies>
	</dependencyManagement>

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

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka-server</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>
</project>

将@EnableEurekaServer加在启动类上

package com.zgy.cloud114;

import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;

import java.util.Scanner;

/**
 * @EnableEurekaServer：说明该应用是一个Eureka服务器
 */
@SpringBootApplication
@EnableEurekaServer
public class Cloud114Application {

	public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String profiles = sc.next();
		new SpringApplicationBuilder(Cloud114Application.class).profiles(profiles).run(args);
	}
}

配置文件：application.yml，配置如下

spring:
  profiles: slaveA
  application:
    name: cloud-114
server:
  port: 8761
eureka:
  client:
    service-url:
      defaultZone: http://slave2:8762/eureka/
---
spring:
  profiles: slaveB
  application:
    name: cloud-114
server:
  port: 8762
eureka:
  client:
    service-url:
      defaultZone: http://slave1:8761/eureka/

启动两个Eureka服务器实例，一个端口号为8761，一个端口号为8762，并分别访问Eureka服务器

ps：启动第一个Eureka服务器实例时，会报错信息如下

com.sun.jersey.api.client.ClientHandlerException: java.net.ConnectException: Connection refused: connect
。。。。。

该错误代码，其实是正常的，因为该Eureka服务器要注册到另外一个Eureka服务器上，但是另外一个Eureka服务器现在还没有启动，当启动第二个Eureka服务器时，就不会报错，因为第二个Eureka服务器是注册到第一个Eureka服务器上的，而第一个Eureka服务器已经启动了。

访问端口号为8761的Eureka服务器

访问端口号为8762的Eureka服务器

创建服务提供者，并启动两个实例

导入依赖

<?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>com.zgy</groupId>
	<artifactId>cloud-police</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>cloud-police</name>
	<description>Demo project for Spring Boot</description>

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

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Dalston.SR5</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

	<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</artifactId>
		</dependency>

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

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

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

package com.zgy.cloudpolice;

import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;

import java.util.Scanner;

/**
 * @EnableEurekaClient：说明该应用是一个客户端
 */
@SpringBootApplication
@EnableEurekaClient
public class CloudPoliceApplication {

	public static void main(String[] args) {

	    /*
	    根据输入的端口号来运行程序
	     */
		Scanner sc = new Scanner(System.in);
        String port = sc.next();
        new SpringApplicationBuilder(CloudPoliceApplication.class).properties("server.port="+port).run(args);
	}
}

package com.zgy.cloudpolice;

public class Police {

    private Integer id;
    private String name;
    private String message;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }
}

package com.zgy.cloudpolice;

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

import javax.servlet.http.HttpServletRequest;

@RestController
public class PoliceController {

    @GetMapping("/call/{id}")
    public Police call(@PathVariable Integer id, HttpServletRequest request){
        Police police = new Police();
        police.setId(id);
        police.setName("张三");
        police.setMessage(request.getRequestURL().toString());

        return police;
    }
}

配置文件

spring:
  application:
    name: cloud-police
eureka:
  client:
    service-url:
      defaultZone: http://localhost:8761/eureka/,http://localhost:8762/eureka/

创建服务调用者

导入依赖

<?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>com.zgy</groupId>
	<artifactId>cloud-person</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>cloud-person</name>
	<description>Demo project for Spring Boot</description>

	<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>

	<dependencyManagement>
		<dependencies>
			<dependency>
				<groupId>org.springframework.cloud</groupId>
				<artifactId>spring-cloud-dependencies</artifactId>
				<version>Dalston.SR5</version>
				<type>pom</type>
				<scope>import</scope>
			</dependency>
		</dependencies>
	</dependencyManagement>

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

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

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

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

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


</project>

package com.zgy.cloudperson;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;

@SpringBootApplication
@EnableEurekaClient
public class CloudPersonApplication {

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

package com.zgy.cloudperson;

import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;

@RestController
@Configuration
public class TestController {

    /*
    @LoadBalanced：该RestTemplate具有负载均衡的功能
     */
    @Bean
    @LoadBalanced
    public RestTemplate getRestTemplate(){
        return new RestTemplate();
    }

    @GetMapping("/router")
    public String router(){
        RestTemplate restTemplate = getRestTemplate();
        String json = restTemplate.getForObject("http://cloud-police/call/100", String.class);
        return json;
    }
}

配置文件

server:
  port: 9000
spring:
  application:
    name: cloud-person
eureka:
  client:
    service-url:
      defaultZone: http://localhost:8761/eureka/,http://localhost:8762/eureka/

模拟客户端请求服务

导入依赖

<?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>com.zgy</groupId>
	<artifactId>cloud-client</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>cloud-client</name>
	<description>Demo project for Spring Boot</description>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>1.5.14.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</artifactId>
		</dependency>

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

		<dependency>
			<groupId>org.apache.httpcomponents</groupId>
			<artifactId>httpclient</artifactId>
			<version>4.5.6</version>
		</dependency>
	</dependencies>

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


</project>

package com.zgy.cloudclient;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class CloudClientApplication {

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

package com.zgy.cloudclient;

import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

import java.io.IOException;

public class TestClient {
    public static void main(String[] args) throws IOException {

        //创建默认的HttpClient
        CloseableHttpClient client = HttpClients.createDefault();
        //循环发请求
        for(int i=0; i<6; i++){
            //使用get方法请求服务
            HttpGet get = new HttpGet("http://localhost:9000/router");
            //获取响应
            HttpResponse response = client.execute(get);
            //输出响应结果
            System.err.println(EntityUtils.toString(response.getEntity()));
        }
    }
}