[Java知识库]微服务项目搭建

目录

????????夫依赖?

????????eureka配置

????????zuul网关

????????接口提供方

????????接口调用方

????????feign调用接口与熔断

springcloud五大组件

• 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
• 注: feign包含ribbon与hystrix

夫依赖?

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.6.RELEASE</version>
        <relativePath/> 
    </parent>

    <!-- 此处定义公用的pom依赖, 若模块要使用 继承此pom即可 -->
    <dependencies>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.12</version>
            <scope>provided</scope>
        </dependency>

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

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

        <dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-all</artifactId>
            <version>5.3.5</version>
        </dependency>

        <!-- 验证码 -->
        <dependency>
            <groupId>com.github.whvcse</groupId>
            <artifactId>easy-captcha</artifactId>
            <version>1.6.2</version>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Finchley.SR2</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

eureka配置

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

server:
  port: 8080

spring:
  application:
    name: ku-eureka

eureka:
  client:
    service-url:
      defaultZone: http://localhost:${server.port}/eureka
    register-with-eureka: false
    fetch-registry: false

  server:
    enable-self-preservation: false
    # 轮训检查
    eviction-interval-timer-in-ms: 5000

@EnableEurekaServer

zuul网关

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

server:
  port: 8083

spring:
  application:
    name: ku-zuul

eureka:
  client:
    service-url:
      defaultZone: http://localhost:8080/eureka
  instance:
    lease-expiration-duration-in-seconds: 20
    lease-renewal-interval-in-seconds: 2
    prefer-ip-address: false
    hostname: zuul


zuul:
  routes:
    ku-provider: /admin/**
    ku-customer: /out/**
  host:
    connect-timeout-millis: 3000
    socket-timeout-millis: 3000

@EnableEurekaClient
@EnableZuulProxy

?zuul拦截器

@Component
public class ZuulConfig extends ZuulFilter {

    /**
     *  可选值有 pre（路由之前）、
     *  routing（路由之时）、
     *  post（路由之后）、
     *  error（发生错误时调用）。
     */
    @Override
    public String filterType() {
        return "pre";
    }

    /**
     * 若有多个过滤器 数字越小优先制行
     */
    @Override
    public int filterOrder() {
        return 0;
    }

    /**
     * 是否过滤
     */
    @Override
    public boolean shouldFilter() {
        return true;
    }

    @Override
    public Object run() throws ZuulException {
        // do something

        RequestContext context = RequestContext.getCurrentContext();
        HttpServletRequest request = context.getRequest();
        String token = request.getHeader("access-token");
        if (StringUtils.isBlank(token)) {
            context.setSendZuulResponse(false);
            context.setResponseStatusCode(HttpStatus.SC_UNAUTHORIZED);
            context.setResponseBody("{\"status\":\"401\", \"text\":\"request error!\"}");
        }
        context.set("token", token);
        return null;
    }
}

接口提供方

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

server:
  port: 8081
spring:
  application:
    name: ku-provider # 要想使用负载均衡 该name必须保持一致

eureka:
  instance:
    # ip注册
    prefer-ip-address: true
    # 心跳时间
    lease-renewal-interval-in-seconds: 2
    # 20s没有收到心跳 剔除注册中心
    lease-expiration-duration-in-seconds: 20

  client:
    service-url:
      defaultZone: http://localhost:8080/eureka

接口调用方

@SpringBootApplication
@EnableEurekaClient
@EnableFeignClients

server:
  port: 8082
spring:
  application:
    name: ku-customer

eureka:
  instance:
    prefer-ip-address: true
    lease-renewal-interval-in-seconds: 2
    lease-expiration-duration-in-seconds: 20

  client:
    service-url:
      defaultZone: http://localhost:8080/eureka

# 启用熔断
feign:
  circuitbreaker:
    enabled: true

feign调用接口与熔断

简化了resttemplate, ribbon请求方式

接口调用

@FeignClient(value = "ku-provider", fallbackFactory = TestFeignClientFallbackFactoryService.class)
@Service
public interface FeignClientService {

    @GetMapping("test")
    String test();
}

熔断

@Service
public class TestFeignClientFallbackFactoryService implements FallbackFactory<FeignClientService> {

    @Override
    public FeignClientService create(Throwable throwable) {
        // 服务熔断执行的方法
        return () -> "服务提供者挂了";
    }
}

注意

????????开启多个服务提供方或使用方, 端口号不一样, eureka中的name保持一致, zuul就会进行负载均衡, 把请求分摊至每个服务, 所以配置中一定要定义连接eureka的心跳时间与剔除时间, 因为zuul进行负载均衡时遵循轮训机制, 如果不配置剔除时间, 一个服务挂了, zuul还会进行请求转发.

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