Spring Cloud

Spring Cloud为开发人员提供了快速构建分布式系统中一些常见模式的工具（例如配置管理，服务发现，断路器，智能路由，微代理，控制总线）。分布式系统的协调导致了样板模式, 使用Spring Cloud开发人员可以快速地支持实现这些模式的服务和应用程序。他们将在任何分布式环境中运行良好，包括开发人员自己的笔记本电脑，裸机数据中心，以及Cloud Foundry等托管平台。

特性

SpringCloud分布式开发五大神兽

    服务发现——Netflix Eureka
    客服端负载均衡——Netflix Ribbon
    断路器——Netflix Hystrix
    服务网关——Netflix Zuul
    分布式配置——Spring Cloud Config

创建服务注册中心eureka server

1：首先创建一个主maven工程

2：在1创建的的工程中创建model，名称为server,作为eureka server

创建过程如下

创建完成后的pom.xml如下

<?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.springcloud</groupId>
   <artifactId>server</artifactId>
   <version>0.0.1-SNAPSHOT</version>
   <packaging>jar</packaging>

   <name>server</name>
   <description>Demo project for Spring Boot</description>

   <parent>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-parent</artifactId>
      <version>1.5.8.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.RELEASE</spring-cloud.version>
   </properties>

   <dependencies>
      <!--eureka server -->
      <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>

   <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>


</project>

4.启动服务注册中心，创建完成后的pom.xml如下
只需要一个注解@EnableEurekaServer，这个注解需要在springboot工程的启动application类上加

/**
 * 启动一个服务注册中心
 *
 * @author wang_
 */
@EnableEurekaServer
@SpringBootApplication
public class ServerApplication {

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

#端口号
server.port= 7080
#
eureka.instance.hostname= localhost
##false来表明自己是一个eureka server
eureka.client.register-with-eureka=false  
##false来表明自己是一个eureka server
eureka.client.fetch-registry=false
eureka.client.service-url.defaultZone= http://${eureka.instance.hostname}:${server.port}/eureka/

#关闭springboot自带的ioc
spring.mvc.favicon.enabled = false

因为现在没有注册服务，所以显示没有服务被发现

创建服务提供者eureka client

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

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.5.8.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-services.version>1.5.0.RELEASE</spring-cloud-services.version>
    <spring-cloud.version>Edgware.RELEASE</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.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>Dalston.RC1</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-milestones</id>
        <name>Spring Milestones</name>
        <url>https://repo.spring.io/milestone</url>
        <snapshots>
            <enabled>false</enabled>
        </snapshots>
    </repository>
</repositories>

/**
 * @author wang_
 * @EnableEurekaClient 表明自己是一个eurekaclient.
 */
@SpringBootApplication
@EnableEurekaClient
@RestController
public class ClientApplication {

    public static void main(String[] args) {

        SpringApplication.run(ClientApplication.class, args);
    }

    @Value("${server.port}")
    String port;
    @RequestMapping("/hi")
    public String home(@RequestParam String name) {
        return "hi "+name+",i am from port:" +port;
    }
}

eureka.client.service-url.defaultZone= http://localhost:7080/eureka/
server.port= 8082
spring.application.name= service-hi


#在application.properties加入认证的用户名和密
security.user.name=root
security.user.password=123456

，启动工程，再次访问http://127.0.0.1:7080/

可以发现有一个服务已经注册了，服务名称和端口号都显示在浏览器中

f访问：
http://127.0.0.1:8082/hi?name=%E7%8E%8B

返回结果：hi 王,i am from port:8082