09 Spring Cloud Alibaba

创建统一的依赖管理

创建一个工程名为 spring-cloud-alibaba-dependencies 的项目,pom.xml 配置文件如下:

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.8.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.chanshiyu</groupId>
<artifactId>spring-cloud-alibaba-dependencies</artifactId>
<version>1.0.0-SNAPSHOT</version>
<packaging>pom</packaging>
<name>spring-cloud-alibaba-dependencies</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 Settings -->
<spring-cloud.version>Greenwich.SR2</spring-cloud.version>
<spring-cloud-alibaba.version>2.1.0.RELEASE</spring-cloud-alibaba.version>
</properties>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>Greenwich.SR2</version>
<type>${spring-cloud.version}</type>
<scope>import</scope>
</dependency>
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-alibaba-dependencies</artifactId>
<version>${spring-cloud-alibaba.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>
<configuration>
<mainClass>com.chanshiyu.nacosprovider.NacosProviderApplication</mainClass>
</configuration>
</plugin>
</plugins>
</build>
</project>

服务注册与发现

服务注册与发现使用 Nacas,直接启动即可。

服务提供者

创建服务提供者

创建一个工程名为 spring-cloud-alibaba-nacos-provider 的项目,pom.xml 配置文件如下:

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>com.chanshiyu</groupId>
<artifactId>spring-cloud-alibaba-dependencies</artifactId>
<version>1.0.0-SNAPSHOT</version>
<relativePath>../spring-cloud-alibaba-dependencies/pom.xml</relativePath>
</parent>
<artifactId>spring-cloud-alibaba-nacos-provider</artifactId>
<version>1.0.0-SNAPSHOT</version>
<name>spring-cloud-alibaba-nacos-provider</name>
<description>Demo project for Spring Boot</description>
<properties>
<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>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<mainClass>com.chanshiyu.nacosprovider.NacosProviderApplication</mainClass>
</configuration>
</plugin>
</plugins>
</build>
</project>

Application

通过 @EnableDiscoveryClient 注解表明是一个 Nacos 客户端,该注解是 Spring Cloud 提供的原生注解。

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

application.yml

spring:
application:
name: nacos-provider
cloud:
nacos:
discovery:
server-addr: 127.0.0.1:8848
server:
port: 8081
management:
endpoints:
web:
exposure:
include: '*'

测试服务

@RestController
public class NacosProviderController {
@Value("${server.port}")
private String port;
@GetMapping("/echo/{message}")
public String echo(@PathVariable String message) {
return String.format("Your message is %s and port is %s", message, port);
}
}

服务消费者

使用 LoadBalanceClientRestTemplate 结合的方式来访问。创建一个工程名为 spring-cloud-alibaba-nacos-consumer 的项目,pom.xml 配置文件如下:

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>com.chanshiyu</groupId>
<artifactId>spring-cloud-alibaba-dependencies</artifactId>
<version>1.0.0-SNAPSHOT</version>
<relativePath>../spring-cloud-alibaba-dependencies/pom.xml</relativePath>
</parent>
<artifactId>spring-cloud-alibaba-nacos-consumer</artifactId>
<version>1.0.0-SNAPSHOT</version>
<name>spring-cloud-alibaba-nacos-consumer</name>
<description>Demo project for Spring Boot</description>
<properties>
<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>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<mainClass>com.chanshiyu.nacosconsumer.NacosConsumerApplication</mainClass>
</configuration>
</plugin>
</plugins>
</build>
</project>

Application

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

application.yml

spring:
application:
name: nacos-consumer
cloud:
nacos:
discovery:
server-addr: 127.0.0.1:8848
server:
port: 9091
management:
endpoints:
web:
exposure:
include: '*'

Configuration

@Configuration
public class NacosConsumerConfiguration {
@Bean
public RestTemplate restTemplate() {
return new RestTemplate();
}
}

测试服务

@RestController
public class NacosConsumerController {
@Autowired
private LoadBalancerClient loadBalancerClient;
@Autowired
private RestTemplate restTemplate;
@Value("${spring.application.name}")
private String appName;
@GetMapping("/echo/app/name")
public String echo() {
// 使用 LoadBalanceClient 和 RestTemolate 结合的方式来访问
ServiceInstance serviceInstance = loadBalancerClient.choose("nacos-provider");
String url = String.format("http://%s:%s/echo/%s", serviceInstance.getHost(), serviceInstance.getPort(), appName);
return restTemplate.getForObject(url, String.class);
}
}

服务消费者(Feign)

创建服务消费者

创建一个工程名为 spring-cloud-alibaba-nacos-consumer-feign 的项目,pom.xml 配置文件如下:

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>com.chanshiyu</groupId>
<artifactId>spring-cloud-alibaba-dependencies</artifactId>
<version>1.0.0-SNAPSHOT</version>
<relativePath>../spring-cloud-alibaba-dependencies/pom.xml</relativePath>
</parent>
<artifactId>spring-cloud-alibaba-nacos-consumer-feign</artifactId>
<version>1.0.0-SNAPSHOT</version>
<name>spring-cloud-alibaba-nacos-consumer-feign</name>
<description>Demo project for Spring Boot</description>
<properties>
<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>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-openfeign</artifactId>
<version>RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
<version>RELEASE</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<mainClass>com.chanshiyu.nacosconsumerfeign.NacosConsumerFeignApplication</mainClass>
</configuration>
</plugin>
</plugins>
</build>
</project>

Application

通过 @EnableFeignClients 注解开启 Feign 功能:

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

application.yml

spring:
application:
name: nacos-consumer-feign
cloud:
nacos:
discovery:
server-addr: 127.0.0.1:8848
sentinel:
transport:
port: 8720
dashboard: localhost:8080
server:
port: 9092
feign:
sentinel:
enabled: true
management:
endpoints:
web:
exposure:
include: '*'

测试服务

创建 Service:

@FeignClient(value = "nacos-provider")
public interface NacosProviderService {
@GetMapping("/echo/{message}")
public String echo(@PathVariable String message);
}

创建 Controller:

@RestController
public class NacosProviderController {
@Autowired
private NacosProviderService nacosProviderService;
@GetMapping("/echo/{message}")
public String echo(@PathVariable String message) {
return nacosProviderService.echo(message);
}
}

熔断器

阿里巴巴开源了 Sentinel 组件,实现了熔断器模式,Spring Cloud 对这一组件进行了整合。

添加依赖

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

application.yml

feign:
sentinel:
enabled: true

fallback

@Component
public class NacosProviderFallback implements NacosProviderService {
@Override
public String echo(String message) {
return "请求失败!";
}
}

service

@FeignClient(value = "nacos-provider", fallback = NacosProviderFallback.class)
public interface NacosProviderService {
@GetMapping("/echo/{message}")
public String echo(@PathVariable String message);
}

仪表盘监控

启动 sentinel 控制台。修改 application.yml,添加 sentinel 配置:

spring:
application:
name: nacos-consumer-feign
cloud:
nacos:
discovery:
server-addr: 127.0.0.1:8848
sentinel:
transport:
port: 8720
dashboard: localhost:8080

路由网关

创建路由网关

创建一个工程名为 spring-cloud-alibaba-nacos-gateway 的项目,pom.xml 配置文件如下:

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>com.chanshiyu</groupId>
<artifactId>spring-cloud-alibaba-dependencies</artifactId>
<version>1.0.0-SNAPSHOT</version>
<relativePath>../spring-cloud-alibaba-dependencies/pom.xml</relativePath>
</parent>
<artifactId>spring-cloud-alibaba-gateway</artifactId>
<version>1.0.0-SNAPSHOT</version>
<name>spring-cloud-alibaba-gateway</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-openfeign</artifactId>
<version>RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
<version>RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-gateway</artifactId>
<version>RELEASE</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<mainClass>com.chanshiyu.gateway.GatewayApplication</mainClass>
</configuration>
</plugin>
</plugins>
</build>
</project>

需要注意:

  • Spring Cloud Gateway 不使用 Web 作为服务器,而是 使用 WebFlux 作为服务器,Gateway 项目已经依赖了 starter-webflux,所以这里 千万不要依赖 starter-web

  • 由于过滤器等功能依然需要 Servlet 支持,故这里还需要依赖 javax.servlet:javax.servlet-api

Application

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

application.yml

spring:
application:
name: spring-gateway
cloud:
# 使用 Naoos 作为服务注册发现
nacos:
discovery:
server-addr: 127.0.0.1:8848
# 使用 Sentinel 作为熔断器
sentinel:
transport:
port: 8721
dashboard: localhost:8080
# 路由网关配置
gateway:
# 设置与服务注册发现组件结合,这样可以采用服务名的路由策略
discovery:
locator:
enabled: true
# 配置路由规则
routes:
# 采用自定义路由 ID(有固定用法,不同的 id 有不同的功能,详见:https://cloud.spring.io/spring-cloud-gateway/2.0.x/single/spring-cloud-gateway.html#gateway-route-filters)
- id: NACOS-CONSUMER
# 采用 LoadBalanceClient 方式请求,以 lb:// 开头,后面的是注册在 Nacos 上的服务名
uri: lb://nacos-consumer
# Predicate 翻译过来是“谓词”的意思,必须,主要作用是匹配用户的请求,有很多种用法
predicates:
# Method 方法谓词,这里是匹配 GET 和 POST 请求
- Method=GET,POST
- id: NACOS-CONSUMER-FEIGN
uri: lb://nacos-consumer-feign
predicates:
- Method=GET,POST
server:
port: 9000
feign:
sentinel:
enabled: true
management:
endpoints:
web:
exposure:
include: '*'
logging:
level:
org.springframework.cloud.gateway: debug

过滤器

@Component
public class AuthFilter implements GlobalFilter, Ordered {
@Override
public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
String token = exchange.getRequest().getQueryParams().getFirst("token");
if (token == null || token.isEmpty()) {
ServerHttpResponse response = exchange.getResponse();
// 封装错误信息
Map<String, Object> responseData = Maps.newHashMap();
responseData.put("code", 401);
responseData.put("message", "非法请求");
responseData.put("cause", "Token is empty");
try {
// 将信息转换为 JSON
ObjectMapper objectMapper = new ObjectMapper();
byte[] data = objectMapper.writeValueAsBytes(responseData);
// 输出错误信息到页面
DataBuffer buffer = response.bufferFactory().wrap(data);
response.setStatusCode(HttpStatus.UNAUTHORIZED);
response.getHeaders().add("Content-Type", "application/json;charset=UTF-8");
return response.writeWith(Mono.just(buffer));
} catch (JsonProcessingException e) {
e.printStackTrace();
}
}
// 传递给下一个过滤器
return chain.filter(exchange);
}
@Override
public int getOrder() {
return Ordered.LOWEST_PRECEDENCE;
}
}