[Java知识库]SpringCloud分布式微服务项目搭建构造父子模块依赖与实现服务提供者与消费者示例

场景

SpringCloud 是若干个框架的集合，包括 spring-cloud-config、spring-cloud-bus 等近 20 个子项目，提供了服务治理、服务网关、智能路由、负载均衡、断路器、监控跟踪、分布式消息队列、配置管理等领域的解决方案。

Spring Cloud 通过 Spring Boot 风格的封装，屏蔽掉了复杂的配置和实现原理，最终给开发者留出了一套简单易懂、容易部署的分布式系统开发工具包。

怎样实现小白从无到有搭建SpringCloud框架并实现父子项目依赖管理。

所需环境：

jdk1.8

mysql 8.0

maven 3.6

IDEA开发工具

注：

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实现

1、最外层父级项目搭建

打开IDEA-New Project-Maven-选择Project SDK为自己对应的-勾选Create from archetype-选择maven-archetype-site

然后设置项目名称和位置等信息

2、为了后续避免出现编码等问题，修改编码格式统一为UTF-8

File-Settings-File Encodings

3、注解生效激活，Build,Exception,Deployment-Compiler-Annotation Processors-Default-Enable annotation processing

Java Compiler版本选择8

4、然后父工程只是用来统一管理项目依赖，所以将其下面的src目录删除掉

修改父级项目的pom文件

<?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.badao</groupId>
  <artifactId>SpringCloudDemo</artifactId>
  <version>1.0-SNAPSHOT</version>
  <packaging>pom</packaging>


  <!-- 统一管理jar包版本 -->
  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
    <junit.version>4.12</junit.version>
    <log4j.version>1.2.17</log4j.version>
    <lombok.version>1.16.18</lombok.version>
    <mysql.version>5.1.47</mysql.version>
    <druid.version>1.1.16</druid.version>
    <mybatis.spring.boot.version>1.3.0</mybatis.spring.boot.version>
  </properties>

  <!-- 子模块继承之后，提供作用：锁定版本+子modlue不用写groupId和version  -->
  <dependencyManagement>
    <dependencies>
      <!--spring boot 2.2.2-->
      <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-dependencies</artifactId>
        <version>2.2.2.RELEASE</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
      <!--spring cloud Hoxton.SR1-->
      <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-dependencies</artifactId>
        <version>Hoxton.SR1</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
      <!--spring cloud alibaba 2.1.0.RELEASE-->
      <dependency>
        <groupId>com.alibaba.cloud</groupId>
        <artifactId>spring-cloud-alibaba-dependencies</artifactId>
        <version>2.1.0.RELEASE</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
      <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>${mysql.version}</version>
      </dependency>
      <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>druid</artifactId>
        <version>${druid.version}</version>
      </dependency>
      <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
        <version>${mybatis.spring.boot.version}</version>
      </dependency>
      <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>${junit.version}</version>
      </dependency>
      <dependency>
        <groupId>log4j</groupId>
        <artifactId>log4j</artifactId>
        <version>${log4j.version}</version>
      </dependency>
      <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <version>${lombok.version}</version>
        <optional>true</optional>
      </dependency>
    </dependencies>
  </dependencyManagement>

  <build>
    <plugins>
      <plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
        <configuration>
          <fork>true</fork>
          <addResources>true</addResources>
        </configuration>
      </plugin>
    </plugins>
  </build>


</project>

将packaging修改为pom

然后使用properties统一管理jar包版本

注意下面声明依赖时使用的dependencyManagement标签，它的作用是：子模块继承之后锁定版本+子modlue不用写groupId和version！！！

Maven中的dependencyManagement元素提供了一种管理依赖版本号的方式。在dependencyManagement元素中声明所依赖的jar包的版本号等信息，

那么所有子项目再次引入此依赖jar包时则无需显式的列出版本号。Maven会沿着父子层级向上寻找拥有dependencyManagement 元素的项目，然后使用它指定的版本号。

如果有多个子项目都引用同一样依赖，则可以避免在每个使用的子项目里都声明一个版本号。当想升级或切换到另一个版本时，只需要在顶层父容器里更新，

而不需要逐个修改子项目；另外如果某个子项目需要另外的一个版本，只需要声明version即可。

dependencyManagement中定义的只是依赖的声明，并不实现引入，因此子项目需要显式的声明需要用的依赖。

5、在父项目下右击-new Module新建子模块

子模块选择Maven项目，注意这里的Module SDK要选对，改为自己所对应的。

然后设置子模块的名称，这里模拟一个服务提供者，提供支付服务并且后续会设定端口号为8001，为了后续

服务较多时方便区分，这里直接在模块名上加上端口号。

新建子模块成功之后，项目结构如下，此时在pom文件中会自动带父子级依赖关系。

子模块中会声明parent的坐标

父级项目pom文件中会新增modules

6、服务提供者子模块业务实现，这里模拟该服务是一个管理支付订单的服务，可以进行支付流水号的新增和查询操作。

修改pom文件，添加需要的项目依赖

<?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>SpringCloudDemo</artifactId>
        <groupId>com.badao</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>cloud-provider-payment8001</artifactId>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </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-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.10</version>
        </dependency>
        <!--mysql-connector-java-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <!--jdbc-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>
</project>

添加yml配置文件，配置项目端口号，mysql数据源，mybatis的相关配置

server:
  port: 8001

spring:
  application:
    name: cloud-payment-service

  datasource:
    type: com.alibaba.druid.pool.DruidDataSource            # 当前数据源操作类型
    driver-class-name: org.gjt.mm.mysql.Driver              # mysql驱动包
   url:jdbc:mysql://localhost:3306/springclouddemo?useUnicode=true&characterEncoding=utf-8&useSSL=false
    username: root
    password: 123456

mybatis:
  mapperLocations: classpath:mapper/*.xml
  type-aliases-package: com.badao.springclouddemo.entities    # 所有Entity别名类所在包

新建项目主启动类PaymentMain8001

package com.badao.springclouddemo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class PaymentMain8001
{
    public static void main(String[] args) {
        SpringApplication.run(PaymentMain8001.class, args);
    }
}

新建数据库表

DROP TABLE IF EXISTS `payment`;
CREATE TABLE `payment`  (
  `id` int(0) NOT NULL AUTO_INCREMENT COMMENT 'id',
  `serial` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NULL DEFAULT NULL COMMENT '支付流水号',
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 4 CHARACTER SET = utf8mb4 COLLATE = utf8mb4_0900_ai_ci ROW_FORMAT = Dynamic;

SET FOREIGN_KEY_CHECKS = 1;

新建dao

package com.badao.springclouddemo.dao;


import com.badao.springclouddemo.entities.Payment;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;


@Mapper
public interface PaymentDao
{
    public int create(Payment payment);

    public Payment getPaymentById(@Param("id") Long id);
}

新建entities

package com.badao.springclouddemo.entities;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

import java.io.Serializable;

@Data
@AllArgsConstructor
@NoArgsConstructor
public class Payment implements Serializable
{
    private Long id;
    private String serial;
}

这里项目中添加了lombok依赖，所以没有set和get方法

为了构造接口返回结果的数据格式，再新建一个实体类

package com.badao.springclouddemo.entities;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;


@Data
@AllArgsConstructor
@NoArgsConstructor
public class CommonResult<T>
{
    private Integer code;
    private String  message;
    private T       data;

    public CommonResult(Integer code, String message)
    {
        this(code,message,null);
    }
}

并且通过注解实现带所有参数和不带任何参数的构造方法，再通过代码实现只有响应码没有数据的构造方法。

新建service

package com.badao.springclouddemo.service;


import com.badao.springclouddemo.entities.Payment;
import org.apache.ibatis.annotations.Param;

 

public interface PaymentService
{
    public int create(Payment payment);

    public Payment getPaymentById(@Param("id") Long id);
}

新建serviceImpl

package com.badao.springclouddemo.service.impl;

import com.badao.springclouddemo.dao.PaymentDao;
import com.badao.springclouddemo.entities.Payment;
import com.badao.springclouddemo.service.PaymentService;
import org.springframework.stereotype.Service;
import javax.annotation.Resource;


@Service
public class PaymentServiceImpl implements PaymentService
{
    @Resource
    private PaymentDao paymentDao;

    public int create(Payment payment)
    {
        return paymentDao.create(payment);
    }

    public Payment getPaymentById(Long id)
    {
        return paymentDao.getPaymentById(id);
    }
}

新建Controller

package com.badao.springclouddemo.controller;


import com.badao.springclouddemo.entities.CommonResult;
import com.badao.springclouddemo.entities.Payment;
import com.badao.springclouddemo.service.PaymentService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;

import org.springframework.web.bind.annotation.*;

import javax.annotation.Resource;

 

@RestController
@Slf4j
public class PaymentController
{
    @Resource
    private PaymentService paymentService;

    @Value("${server.port}")
    private String serverPort;

 

    @PostMapping(value = "/payment/create")
    public CommonResult create(@RequestBody Payment payment)
    {
        int result = paymentService.create(payment);
        log.info("*****插入结果："+result);

        if(result > 0)
        {
            return new CommonResult(200,"插入数据库成功,serverPort: "+serverPort,result);
        }else{
            return new CommonResult(444,"插入数据库失败",null);
        }
    }

    @GetMapping(value = "/payment/get/{id}")
    public CommonResult<Payment> getPaymentById(@PathVariable("id") Long id)
    {
        Payment payment = paymentService.getPaymentById(id);

        if(payment != null)
        {
            return new CommonResult(200,"查询成功,serverPort:  "+serverPort,payment);
        }else{
            return new CommonResult(444,"没有对应记录,查询ID: "+id,null);
        }
    }

}

新建mapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >

<mapper namespace="com.badao.springclouddemo.dao.PaymentDao">

    <insert id="create" parameterType="com.badao.springclouddemo.entities.Payment" useGeneratedKeys="true" keyProperty="id">
        insert into payment(serial)  values(#{serial});
    </insert>


    <resultMap id="BaseResultMap" type="com.badao.springclouddemo.entities.Payment">
        <id column="id" property="id" jdbcType="BIGINT"/>
        <id column="serial" property="serial" jdbcType="VARCHAR"/>
    </resultMap>
    <select id="getPaymentById" parameterType="Long" resultMap="BaseResultMap">
        select * from payment where id=#{id};
    </select>

</mapper>

业务类都实现后项目结构

7、启动该服务，访问接口进行测试

数据库插入一条数据，调用查询接口

使用postman调用插入接口

注意这里的接口调用方式是接口参数没加@RequestBody的调用方式。

8、按照上面的新建服务提供者的流程，在父级项目上再右键新建服务消费者模块，模拟消费者进行购买后调用支付服务的操作。

这里命名为消费者订单，并打算使用88端口

修改pom文件，这里pom文件只需要简单的web依赖即可，不再需要mysql等相关的操作。

<?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>SpringCloudDemo</artifactId>
        <groupId>com.badao</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>cloud-consumer-order88</artifactId>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </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-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>
</project>

新建yml配置文件，只需要声明端口号即可

server:
  port: 88

新建主启动类OrderMain88

package com.badao.springclouddemo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class OrderMain88
{
    public static void main(String[] args) {
            SpringApplication.run(OrderMain88.class, args);
    }
}

9、为了实现该消费者服务调用前面订单生成的服务，需要在该消费者服务中实现一个httpClient，用来实现服务之间的接口调用

可以通过配置和注入RestTemplate来实现

新建config/ApplicationContextConfig配置类

package com.badao.springclouddemo.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.client.RestTemplate;

@Configuration
public class ApplicationContextConfig
{
    @Bean
    public RestTemplate getRestTemplate()
    {
        return new RestTemplate();
    }
}

新建Controller用来发起对服务提供者服务的调用

package com.badao.springclouddemo.controller;


import com.badao.springclouddemo.entities.CommonResult;
import com.badao.springclouddemo.entities.Payment;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;

import javax.annotation.Resource;


@RestController
@Slf4j
public class OrderController
{

    public static final String PAYMENT_URL = "http://localhost:8001";

    @Resource
    private RestTemplate restTemplate;


    @GetMapping("/consumer/payment/create")
    public CommonResult<Payment> create(Payment payment)
    {
        return restTemplate.postForObject(PAYMENT_URL +"/payment/create",payment,CommonResult.class);
    }

    @GetMapping("/consumer/payment/get/{id}")
    public CommonResult<Payment> getPayment(@PathVariable("id") Long id)
    {
        return restTemplate.getForObject(PAYMENT_URL+"/payment/get/"+id,CommonResult.class);
    }

}

同样的把上面的两个实体类拿过来

10、启动上面服务提供者并启动消费者，然后通过消费者访问服务提供者的服务

调用查询服务

调用插入服务

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