06、SpringCloud之feign的工程化实例(分布式工程)(二)

二、基于feign的工程化项目创建

2.1、案例目标及项目架构图

api模块依赖domain模块,然后其他服务依赖该api接口模块。

domain:实体类。

api:放置公共接口,例如feign接口。

06、SpringCloud之feign的工程化实例(分布式工程)(二)

2.2、实战—项目模块搭建

2.2.1、各个模块介绍及父模块pom.xml

项目模块展示:

注册中心:使用之前eureka案例中的即可

06、SpringCloud之feign的工程化实例(分布式工程)(二)

接着按照2.1中的项目架构图来进行搭建模块,分别是:api模块、doamin模块、order服务模块以及user服务模块

依赖关系如下:

api模块依赖domain模块。

domain:添加对应的实体类。

api:主要是编写对应的远程调用api接口以及断路器实现类。

order、user服务模块依赖api模块。

order服务主要是对外提供服务。

user服务中某个接口会进行调用order服务。

06、SpringCloud之feign的工程化实例(分布式工程)(二)

所有的包名统一前缀为com.changlu。

对于04-feign-project父模块的pom.xml配置如下:

<?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">
    <!--  父模块依赖  -->
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.12.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <modelVersion>4.0.0</modelVersion>
    <!-- 创建好子模块之后,就会自动添加packaging以及modules管理   -->
    <groupId>com.changlu</groupId>
    <artifactId>04-feign-project</artifactId>
    <packaging>pom</packaging>
    <version>1.0-SNAPSHOT</version>
    <modules>
        <module>domain-project</module>
        <module>common-api</module>
        <module>user-center</module>
        <module>order-center</module>
    </modules>
    <!--全局版本控制-->
    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
        <java.version>1.8</java.version>
        <spring-cloud.version>Hoxton.SR12</spring-cloud.version>
    </properties>
    <!--  全局依赖的模块  -->
    <dependencies>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
    </dependencies>
    <!--  全局管理的依赖版本(不会被直接引入)  -->
    <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>
    <!-- 打包编译   -->
<!--    <build>-->
<!--    </build>-->
</project>

2.2.2、domain-project模块

说明:该模块主要放置一些实体类。

06、SpringCloud之feign的工程化实例(分布式工程)(二)

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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>04-feign-project</artifactId>
        <groupId>com.changlu</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>
    <artifactId>domain-project</artifactId>
</project>

Order.java实体类:

package com.changlu.domain;
import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;
/**
 * @Description:
 * @Author: changlu
 * @Date: 2:30 PM
 */
@Data
@AllArgsConstructor
@NoArgsConstructor
@Builder
public class Order {
    private Integer orderId;
    private String orderName;
    private Double price;
}

2.2.3、common-api模块

说明:这个模块主要放一些公共的api接口,例如feign接口以及hystrix断路器接口。

06、SpringCloud之feign的工程化实例(分布式工程)(二)

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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>04-feign-project</artifactId>
        <groupId>com.changlu</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>
    <artifactId>common-api</artifactId>
    <dependencies>
        <!--    依赖domain    -->
        <dependency>
            <groupId>com.changlu</groupId>
            <artifactId>domain-project</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
        </dependency>
    </dependencies>
</project>

com/changlu/feign/UserOrderFeign.java:feign接口规范

package com.changlu.feign;
import com.changlu.domain.Order;
import com.changlu.feign.hystrix.*;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
/**
 * @Description:
 * @Author: changlu
 * @Date: 2:39 PM
 */
@FeignClient(value = "order-service", fallback = UserOrderFeignHystrix.class)
public interface UserOrderFeign {
    @GetMapping("/order/{id}")
    Order getOrderById(@PathVariable("id")Integer id);
}

com.changlu.feign.hystrix.UserOrderFeignHystrix:对应上面feign的断路器

package com.changlu.feign.hystrix;
import com.changlu.domain.Order;
import com.changlu.feign.UserOrderFeign;
import org.springframework.stereotype.Component;
/**
 * @Description:
 * @Author: changlu
 * @Date: 2:43 PM
 */
@Component
public class UserOrderFeignHystrix implements UserOrderFeign {
    @Override
    public Order getOrderById(Integer id) {
        return null;
    }
}

2.2.4、order-center服务模块

说明:该模块主要是对外提供订单服务。

06、SpringCloud之feign的工程化实例(分布式工程)(二)

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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>04-feign-project</artifactId>
        <groupId>com.changlu</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>
    <artifactId>order-center</artifactId>
    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>
    <dependencies>
        <!--    引入api依赖    -->
        <dependency>
            <groupId>com.changlu</groupId>
            <artifactId>common-api</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
        <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>
    </dependencies>
</project>

配置文件application.yaml:

server:
  port: 8081
spring:
  application:
    name: order-service
eureka:
  client:
    service-url:
      defaultZone: http://localhost:8761/eureka
  instance:
    hostname: localhost
    instance-id: ${eureka.instance.hostname}:${spring.application.name}:${server.port}

①添加启动器注解,开启服务注册

package com.changlu;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
/**
 * @Description:
 * @Author: changlu
 * @Date: 2:36 PM
 */
@SpringBootApplication
@EnableEurekaClient
public class OrderServiceApplication {
    public static void main(String[] args) {
        SpringApplication.run(OrderServiceApplication.class, args);
    }
}

②创建订单控制器:com.changlu.controller.OrderController

package com.changlu.controller;
import com.changlu.domain.Order;
import com.changlu.feign.UserOrderFeign;
import org.springframework.web.bind.annotation.RestController;
/**
 * @Description:
 * @Author: changlu
 * @Date: 2:38 PM
 */
@RestController
public class OrderController implements UserOrderFeign {
        @Override
        public Order getOrderById(Integer id) {
            Order order = Order.builder()
                    .orderId(id)
                    .price(100.0)
                    .orderName("牛奶布丁").build();
            return order;
        }
}

2.2.5、user-center服务模块

说明:该用户服务主要是对外提供用户服务,在提供用户服务过程中会进行调用订单服务,其中就涉及到了openfeign组件以及hystrix断路器组件(需要手动开启)。

06、SpringCloud之feign的工程化实例(分布式工程)(二)

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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>04-feign-project</artifactId>
        <groupId>com.changlu</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>
    <artifactId>user-center</artifactId>
    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>
    <dependencies>
        <!--    引入api依赖    -->
        <dependency>
            <groupId>com.changlu</groupId>
            <artifactId>common-api</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
        <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>
    </dependencies>
</project>

配置文件application.yaml:

server:
  port: 8082
spring:
  application:
    name: user-service
eureka:
  client:
    service-url:
      defaultZone: http://localhost:8761/eureka
  instance:
    hostname: localhost
    instance-id: ${eureka.instance.hostname}:${spring.application.name}:${server.port}
# 开启熔断
feign:
  hystrix:
    enabled: true

①创建启动器,添加服务注册以及feign包扫描

package com.changlu;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.cloud.openfeign.EnableFeignClients;
/**
 * @Description:
 * @Author: changlu
 * @Date: 2:52 PM
 */
@SpringBootApplication
@EnableEurekaClient
@EnableFeignClients(basePackages = "com.changlu.feign")
public class UserServiceApplication {
    public static void main(String[] args) {
        SpringApplication.run(UserServiceApplication.class, args);
    }
}

②创建用户控制器:com.changlu.controller.UserController

package com.changlu.controller;
import com.changlu.domain.Order;
import com.changlu.feign.UserOrderFeign;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
/**
 * @Description:
 * @Author: changlu
 * @Date: 2:53 PM
 */
@RestController
public class UserController {
    @Autowired
    private UserOrderFeign feign;
    @GetMapping("/user/order/{userId}")
    public Order getOrderByUserId(@PathVariable("userId")Integer userId) {
        //根据用户id获取到订单id
        Integer id = 1111;
        Order order = feign.getOrderById(id);
        return order;
    }
}

至此,我们的项目模块搭建完成。

2.3、项目模块测试、

我们启动注册中心、订单服务以及用户服务:

06、SpringCloud之feign的工程化实例(分布式工程)(二)

接着我们来访问用户服务:http://localhost:8082/user/order/123

06、SpringCloud之feign的工程化实例(分布式工程)(二)

接着我们将订单服务关闭,再此访问查看下:

06、SpringCloud之feign的工程化实例(分布式工程)(二)

成功,当订单服务不可用时,即可返回对应断路器的内容。