springcloud初体验（一句话，真香！）

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一、微服务简介

Ⅰ、我对微服务的理解

微服务是软件开发的一种架构方式，由单一的应用小程序构成的小服务；一个软件系统由多个服务组成；在微服务中，服务是细粒度的，协议是轻量级的(部署简单、性能开销小）

Ⅱ、为什么要使用微服务?

随着时代的发展，单体架构(MVC三层模型)越来越不能满足企业的要求；业务规模的不断扩大、团队开发人员的增多，使得单体架构出现了以下几个问题：

(1)部署效率低（比如代码量非常多，依赖的包非常多，那么每一次编译打包、部署测试的时间就会很久）
(2)团队开发成本高（如果某个模块出现问题，可能就要多人修改）
(3)高可用性低（打成war包部署之后，如果某一块出现了问题，其他模块都会受到影响)
(4)一旦代码膨胀(简单了说你写的代码量大，但功能没实现几个，浪费资源)，上线就会变慢

SOA(面向服务编程）便出现了

SOA简介

SOA是一个组件模型，它将应用程序的不同功能单元（称为服务）进行拆分，并通过这些服务之间定义良好的接口和协议联系起来。

虽然解决了服务的启动时间，但服务化也有很大的缺点

1、耦合度较高（一个依赖可能另一个模块，另外一个模块又可能依赖其他模块)
2、公司成本高（每一个模块都要由相应的人员或者团队维护)

2014年，随着容器化技术的成熟以及 DevOps 文化的兴起，微服务便应运而生了

微服务的特点

1.服务细粒度
2.协议轻量级
3.部署简单
4.服务的独立维护性

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二、spring cloud

Ⅰ、springcloud介绍

springcloud是分布式微服务架构的一站式解决方案，是多种微服务架构落地技术的集合体。

1.分布式/版本化配置
2.服务注册和发现
3.路由
4.服务到服务的通话
5.负载均衡
6.断路器
7.全局锁
8.领导选举和集群状态
9.分布式消息传递

SpringCloud的官网地址：https://spring.io/projects/spring-cloud#overview

Ⅱ、boot和cloud的版本选型

1.进入springcloud官方页面:https://spring.io/projects/spring-cloud#learn


2. LEARN->Reference Doc.
3. 版本选择

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三、springcloud初级项目体验

最近发现网络上很多springcloud入门体验都是关于消费-订单的小Demo，那我当然不能落后了（菜是原罪）

PRE： 模拟服务间调用之流程分析

1、创建一个父项目（统一管理子模块依赖版本）
2、创建第一个子模块-----》订单服务模块
3、创建第二个子模块-----》客户消费模块

3.1、订单服务模块

编写代码之前应该先构思好流程，如果直接就去码代码，码了一会可能又要添添改改；还有可能做完项目之后又要对项目进行重构，这就是没有构思好流程。
1、技术选型
2、业务流程
3、核心业务分析
4、代码优化
…

Ⅰ、数据库表设计

Ⅱ、创建一个父工程

删除多余的文件，留下一个pom.xml文件

pom文件依赖

<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>4.0.0modelVersion>

    <groupId>com.cloudgroupId>
    <artifactId>springcloud_allartifactId>
    <version>1.0-SNAPSHOTversion>
    <modules>
    ## 创建了子模块之后会自动加入
     ##   <module>payment-modulemodule>
    modules>
    <packaging>pompackaging>
    <properties>
        <project.build.sourceEncoding>UTF-8project.build.sourceEncoding>
        <maven.compiler.source>1.8maven.compiler.source>
        <maven.compiler.target>1.8maven.compiler.target>
        <junit.version>4.13junit.version>
        <log4j.version>1.2.17log4j.version>
        <lombok.version>1.16.18lombok.version>
        <mysql.version>8.0.19mysql.version>
        <druid.version>1.2.4druid.version>
        <mybatis.spring.boot.version>2.1.4mybatis.spring.boot.version>
        <druid.spring.boot.version>1.2.4druid.spring.boot.version>
        <springfox-swagger-ui.version>2.9.2springfox-swagger-ui.version>
        <springfox-swagger2.version>2.9.2springfox-swagger2.version>
    properties>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.bootgroupId>
                <artifactId>spring-boot-dependenciesartifactId>
                <version>2.4.3version>
                <type>pomtype>
                <scope>importscope>
            dependency>
            
            <dependency>
                <groupId>org.springframework.cloudgroupId>
                <artifactId>spring-cloud-dependenciesartifactId>
                <version>2020.0.2version>
                <type>pomtype>
                <scope>importscope>
            dependency>
            
            <dependency>
                <groupId>com.alibaba.cloudgroupId>
                <artifactId>spring-cloud-alibaba-dependenciesartifactId>
                <version>2021.1version>
                <type>pomtype>
                <scope>importscope>
            dependency>
            <dependency>
                <groupId>mysqlgroupId>
                <artifactId>mysql-connector-javaartifactId>
                <version>${mysql.version}version>
            dependency>
            <dependency>
                <groupId>com.alibabagroupId>
                <artifactId>druidartifactId>
                <version>${druid.version}version>
            dependency>
            <dependency>
                <groupId>org.mybatis.spring.bootgroupId>
                <artifactId>mybatis-spring-boot-starterartifactId>
                <version>${mybatis.spring.boot.version}version>
            dependency>
            <dependency>
                <groupId>com.alibabagroupId>
                <artifactId>druid-spring-boot-starterartifactId>
                <version>${druid.spring.boot.version}version>
            dependency>
            <dependency>
                <groupId>io.springfoxgroupId>
                <artifactId>springfox-swagger-uiartifactId>
                <version>${springfox-swagger-ui.version}version>
            dependency>
            <dependency>
                <groupId>io.springfoxgroupId>
                <artifactId>springfox-swagger2artifactId>
                <version>${springfox-swagger2.version}version>
            dependency>
        dependencies>
    dependencyManagement>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.bootgroupId>
                <artifactId>spring-boot-maven-pluginartifactId>
                <configuration>
                    <fork>truefork>
                    <addResources>trueaddResources>
                configuration>
            plugin>
        plugins>
    build>
project>

Ⅲ、创建子订单模块

右键->New->Module



PaymentApplication启动类

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

Ⅲ、子模块代码编写

Ⅲ.Ⅰ、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>springcloud_all</artifactId>
        <groupId>com.cloud</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.pay</groupId>
    <artifactId>payment-module</artifactId>
    <dependencies>
<!--        web+监控-->
        <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>
<!--        mybatis-->
        <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>
        </dependency>
<!--        mysql-->
        <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.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger-ui</artifactId>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger2</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
    </dependencies>

</project>

Ⅲ.Ⅱ、application.yml 配置文件编写

server:
  port: 8081

spring:
  application:
    name: payment-module
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/cloud?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone=UTC
    username: root
    password: hao20001010
mybatis:
  mapper-locations: classpath:mapper/*.xml
  type-aliases-package: com.cloud.entity

Ⅲ.Ⅲ、Controller层编写

package com.cloud.controller;


import com.cloud.Service.PaymentService;

import com.cloud.entity.Payment;
import com.cloud.entity.Result;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import io.swagger.annotations.ApiOperation;
import lombok.extern.slf4j.Slf4j;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;

/**
 * @author:抱着鱼睡觉的喵喵
 * @date:2021/4/18
 * @description:
 */
@RestController
@Slf4j
@Api(value = "《----订单模块----》")
public class PaymentController {
     
    private static final Logger logger = LoggerFactory.getLogger(PaymentController.class);
    @Resource
    private PaymentService paymentService;

    /**
     * 创建订单模块
     * @api /payment/create
     * @param payment Payment实体类
     * @return  Result<>
     */
    @ApiOperation(value = "创建订单")
    @PostMapping(value = "/payment/create")
    public Result create(@RequestBody Payment payment) {
     
        int result = paymentService.create(payment);
        logger.info("插入结果========》" +result);
        if (result > 0) {
     
            return new Result(200,"插入成功", result);
        } else {
     
            return new Result(500, "插入失败", null);
        }
    }

    /**
     * 订单查询模块
     * @api /payment/get/{id}
     * @param id  编号
     * @return Payment实体类
     */
    @GetMapping(value = "/payment/get/{id}")
    @ApiModelProperty(value = "订单查询")
    public Result getPaymentById(@PathVariable(value = "id") Integer id) {
     
        Payment payment = paymentService.getPaymentById(id);
        logger.info("订单查询结果=========>"+payment);
        if (payment != null) {
     
            return new Result(200, "查询成功", payment);
        } else {
     
            logger.error("订单插叙失败！请排查原因");
            return new Result(500, "查询失败,无该订单ID:"+id, null);
        }
    }
}

Ⅲ.Ⅳ、service层

public interface PaymentService {
     
    int create(Payment payment);
    Payment getPaymentById(@Param("id") Integer id);
}

@Service
public class PaymentServiceImpl implements PaymentService {
     

    @Resource
    private PaymentMapper paymentMapper;

    @Override
    public int create(Payment payment) {
     
        return paymentMapper.create(payment);
    }

    @Override
    public Payment getPaymentById(Integer id) {
     
        return paymentMapper.getPaymentById(id);
    }
}

Ⅲ.Ⅴ、mapper层

@Mapper
public interface PaymentMapper {
     
    int create(Payment payment);
    Payment getPaymentById(@Param("id") Integer id);
}

Ⅲ.Ⅵ、mapper.xml

<mapper namespace="com.cloud.mapper.PaymentMapper">
    <insert id="create" parameterType="payment" keyProperty="id" useGeneratedKeys="true">
        insert into payment(orders)values(#{orders})
    insert>
    <select id="getPaymentById" parameterType="payment" resultMap="BaseResultMap" >
        select * from payment where id=#{id}
    select>
    <resultMap id="BaseResultMap" type="payment">
        <id column="id" property="id" jdbcType="INTEGER"/>
        <id column="orders" property="orders" jdbcType="VARCHAR"/>
    resultMap>
mapper>

Ⅳ、统一结果封装类及其实体类

@Data
public class Result<T> implements Serializable {
     
    private Integer code;
    private String message;
    private T data;

    public Result(){
     }

    public Result(Integer code, String msg) {
     
        this(code, msg, null);
    }
    public Result(Integer code, String msg, T data) {
     
        this.code = code;
        this.message = msg;
        this.data = data;
    }
}

@Data
@AllArgsConstructor
@NoArgsConstructor
@ApiModel(value = "Payment实体类")
public class Payment {
     

    @ApiModelProperty(value = "id")
    private Integer id;
    @ApiModelProperty(value = "订单信息")
    private String orders;
}

五、测试

3.2、消费服务模块

消费模块项目结构图

Payment、Result以及ConsumerApplication启动类和上面类似。

PRE：RestTemplate详解

RestTemplate是spring封装的一个服务端远程HTTP请求工具，支持常见的Rest请求（get、post等）
简单了说就是用来远程调用的，因为你订单模块是一个服务，消费模块又是一个单独的服务，两个服务端的端口号要进行交互，所以就有了RestTemplate

RestTemplate是服务端HTTP调用的
Jsonp是客户端调用的

Ⅰ、消费模块application.yml配置

server:
  port: 80

Ⅱ、配置类注入RestTemplate

@Configuration
public class ApplicationContextConfig {
     

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

@Configuration : 该注解类似于beans

@Bean：当然就类似于bean了

Ⅲ、ConsumerController

@RestController
@Api(value = "消费模块")
public class ConsumerController {
     

    private static final String CONSUMER_URL = "http://localhost:8081";
    @Resource
    private RestTemplate restTemplate;

    @GetMapping("/consumer/payment/create")
    @ApiOperation(value = "模拟添加")
    public Result<Payment> create(Payment payment) {
     
        return restTemplate.postForObject(CONSUMER_URL + "/payment/create", payment, Result.class);
    }

    @ApiOperation(value = "模拟获取")
    @GetMapping("/consumer/payment/get/{id}")
    public Result<Payment> getPayment(@PathVariable(value = "id") Integer id) {
     
        return restTemplate.getForObject(CONSUMER_URL + "/payment/get/" + id, Result.class);
    }
}

3.3、全局测试

到此结束！