spring cloud

spring cloud是一个分布式的整体解决方案。spring cloud为开发者提供了在分布式系统（配置管理、服务发现、熔断、路由、微代理、控制总线、一次性token、全局锁、leader选举、分布式session、集群状态）中快速构建的工具，使用spring cloud的开发者可以快速的启动服务或构建应用，同时能够快速和云平台资源进行对接。 spring cloud分布式开发五大常用组件：

服务发现——Netflix Eureka客户端负载均衡——Netflix Ribbon断路器——Netflix Hystrix服务网关——Netflix Zuul分布式配置——spring cloud Config

Netflix Eureka

示例： 创建三个项目：eureka-server、user-service-provider、user-service-consumer

eureka-server

pom.xml

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.qrxqrx</groupId> <artifactId>testcloud</artifactId> <version>0.0.1-SNAPSHOT</version> <name>testcloud</name> <description>Demo project for Spring Boot</description> <properties> <java.version>1.8</java.version> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <spring-boot.version>2.3.0.RELEASE</spring-boot.version> <spring-cloud.version>Hoxton.SR4</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> <exclusions> <exclusion> <groupId>org.junit.vintage</groupId> <artifactId>junit-vintage-engine</artifactId> </exclusion> </exclusions> </dependency> </dependencies> <dependencyManagement> <dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-dependencies</artifactId> <version>${spring-cloud.version}</version> <type>pom</type> <scope>import</scope> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-dependencies</artifactId> <version>${spring-boot.version}</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement> <build> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <version>3.8.1</version> <configuration> <source>1.8</source> <target>1.8</target> <encoding>UTF-8</encoding> </configuration> </plugin> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> <version>2.3.0.RELEASE</version> <configuration> <mainClass>com.qrxqrx.testcloud.TestcloudApplication</mainClass> </configuration> <executions> <execution> <id>repackage</id> <goals> <goal>repackage</goal> </goals> </execution> </executions> </plugin> </plugins> </build> </project>

application.yml

server: port: 8761 eureka: instance: hostname: eureka-server #eureka实例的主机名 client: register-with-eureka: false #不把自己注册到eureka上 fetch-registry: false #不从eureka上获取服务的注册信息 service-url: defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/ server: enable-self-preservation: false

TestcloudApplication类：

package com.qrxqrx.testcloud; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer; @EnableEurekaServer @SpringBootApplication public class TestcloudApplication { public static void main(String[] args) { SpringApplication.run(TestcloudApplication.class, args); } }

user-service-provider

pom.xml

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.qrxqrx</groupId> <artifactId>testcloud-client</artifactId> <version>0.0.1-SNAPSHOT</version> <name>testcloud-client</name> <description>Demo project for Spring Boot</description> <properties> <java.version>1.8</java.version> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <spring-boot.version>2.3.0.RELEASE</spring-boot.version> <spring-cloud.version>Hoxton.SR4</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-client</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> <exclusions> <exclusion> <groupId>org.junit.vintage</groupId> <artifactId>junit-vintage-engine</artifactId> </exclusion> </exclusions> </dependency> </dependencies> <dependencyManagement> <dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-dependencies</artifactId> <version>${spring-cloud.version}</version> <type>pom</type> <scope>import</scope> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-dependencies</artifactId> <version>${spring-boot.version}</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement> <build> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <version>3.8.1</version> <configuration> <source>1.8</source> <target>1.8</target> <encoding>UTF-8</encoding> </configuration> </plugin> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> <version>2.3.0.RELEASE</version> <configuration> <mainClass>com.qrxqrx.testcloudclient.TestcloudClientApplication</mainClass> </configuration> <executions> <execution> <id>repackage</id> <goals> <goal>repackage</goal> </goals> </execution> </executions> </plugin> </plugins> </build> </project>

application.yml

server: port: 0 spring: application: name: user-service-provider eureka: client: service-url: defaultZone: http://localhost:8761/eureka/

User类：

package com.qrxqrx.testcloudclient.field; import java.io.Serializable; public class User implements Serializable { String name; Integer age; public User() { } public User(String name, Integer age) { this.name = name; this.age = age; } public String getName() { return name; } public void setName(String name) { this.name = name; } public Integer getAge() { return age; } public void setAge(Integer age) { this.age = age; } @Override public String toString() { return "User{" + "name='" + name + '\'' + ", age=" + age + '}'; } }

UserService类：

package com.qrxqrx.testcloudclient.service; import com.qrxqrx.testcloudclient.field.User; import org.springframework.stereotype.Service; @Service public class UserService { public User getUsers() { return new User("aaa",11); } }

UserController类：

package com.qrxqrx.testcloudclient.controller; import com.qrxqrx.testcloudclient.field.User; import com.qrxqrx.testcloudclient.service.UserService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RestController; @RestController public class UserController { @Autowired UserService userService; @GetMapping("/user") public User getUser() { System.out.println(userService.getUsers()); return userService.getUsers(); } }

TestcloudClientApplication类：

package com.qrxqrx.testcloudclient; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; @SpringBootApplication public class TestcloudClientApplication { public static void main(String[] args) { SpringApplication.run(TestcloudClientApplication.class, args); } }

user-service-consumer

pom.xml

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.qrxqrx</groupId> <artifactId>testcloud-client-consumer</artifactId> <version>0.0.1-SNAPSHOT</version> <name>testcloud-client-consumer</name> <description>Demo project for Spring Boot</description> <properties> <java.version>1.8</java.version> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <spring-boot.version>2.3.0.RELEASE</spring-boot.version> <spring-cloud.version>Hoxton.SR4</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-client</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> <exclusions> <exclusion> <groupId>org.junit.vintage</groupId> <artifactId>junit-vintage-engine</artifactId> </exclusion> </exclusions> </dependency> </dependencies> <dependencyManagement> <dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-dependencies</artifactId> <version>${spring-cloud.version}</version> <type>pom</type> <scope>import</scope> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-dependencies</artifactId> <version>${spring-boot.version}</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement> <build> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <version>3.8.1</version> <configuration> <source>1.8</source> <target>1.8</target> <encoding>UTF-8</encoding> </configuration> </plugin> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> <version>2.3.0.RELEASE</version> <configuration> <mainClass>com.qrxqrx.testcloudclientconsumer.TestcloudClientConsumerApplication</mainClass> </configuration> <executions> <execution> <id>repackage</id> <goals> <goal>repackage</goal> </goals> </execution> </executions> </plugin> </plugins> </build> </project>

application.yml

server: port: 0 spring: application: name: user-service-consumer eureka: client: service-url: defaultZone: http://localhost:8761/eureka/

User类：

package com.qrxqrx.testcloudclientconsumer.field; import java.io.Serializable; public class User implements Serializable { String name; Integer age; public User() { } public User(String name, Integer age) { this.name = name; this.age = age; } public String getName() { return name; } public void setName(String name) { this.name = name; } public Integer getAge() { return age; } public void setAge(Integer age) { this.age = age; } @Override public String toString() { return "User{" + "name='" + name + '\'' + ", age=" + age + '}'; } }

UserController类：

package com.qrxqrx.testcloudclientconsumer.controller; import com.qrxqrx.testcloudclientconsumer.field.User; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.cloud.client.loadbalancer.LoadBalanced; import org.springframework.context.annotation.Bean; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RestController; import org.springframework.web.client.RestTemplate; @RestController public class UserController { @Autowired private RestTemplate restTemplate; @Bean @LoadBalanced public RestTemplate restTemplate() { return new RestTemplate(); } @GetMapping("/getuser") public User getUser() { return restTemplate.getForObject("http://user-service-provider:0/user", User.class); } }

TestcloudClientConsumerApplication类：

package com.qrxqrx.testcloudclientconsumer; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; @SpringBootApplication public class TestcloudClientConsumerApplication { public static void main(String[] args) { SpringApplication.run(TestcloudClientConsumerApplication.class, args); } }

http://localhost:8761/可以访问eureka的注册中心dashboard。图中可以看到注册的服务。