SpringCloud 详解(二)

发布于 2022-04-12  130 次阅读


支付模块(服务生产者)

准备工作

创建一个 Module,一个空的 Maven 项目。并导入下面的依赖。

<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>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
    </dependency>
    <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>

在 resources 文件夹下创建 application.yaml 配置文件,并加入下面的配置。

server:
  port: 8001

spring:
  application:
    name: payment
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/springcloud?useUnicode=true&characterEncoding=utf-8&useSSL=false
    username: root
    password: root

mybatis:
  mapperLocations: classpath:mapper/*.xml
  type-aliases-package: ml.guest997.pojo

创建主启动类。

package ml.guest997;

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

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

运行下面的 sql 语句创建数据库和表。

CREATE DATABASE `springcloud`;
USE `springcloud`;
CREATE TABLE `payment`(
    `id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT 'ID',
    `serial` varchar(200) DEFAULT '',
    PRIMARY KEY (id)
)ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8mb4

POJO 层

package ml.guest997.pojo;

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

import java.io.Serializable;

@Data
@AllArgsConstructor
@NoArgsConstructor
public class Payment implements Serializable {
    private static final long serialVersionUID = -3231455795280061701L;
    private Long id;
    private String serial;
}
package ml.guest997.pojo;

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 = code;
        this.message = message;
        this.data = null;
    }
}

Dao 层

package ml.guest997.dao;

import ml.guest997.pojo.Payment;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;

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

    Payment getPaymentById(@Param("id") Long id);
}
<?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="ml.guest997.dao.PaymentDao">

    <insert id="add" parameterType="Payment" useGeneratedKeys="true" keyProperty="id">
        insert into payment(serial)
        values (#{serial});
    </insert>

    <resultMap id="BaseResultMap" type="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>

Service 层

package ml.guest997.service;

import ml.guest997.pojo.Payment;
import org.apache.ibatis.annotations.Param;

public interface PaymentService {
    int add(Payment payment);

    Payment getPaymentById(@Param("id") Long id);
}
package ml.guest997.service.impl;

import ml.guest997.dao.PaymentDao;
import ml.guest997.pojo.Payment;
import ml.guest997.service.PaymentService;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;

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

    @Override
    public int add(Payment payment) {
        return paymentDao.add(payment);
    }

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

Controller 层

package ml.guest997.controller;

import lombok.extern.slf4j.Slf4j;
import ml.guest997.pojo.CommonResult;
import ml.guest997.pojo.Payment;
import ml.guest997.service.PaymentService;
import org.springframework.web.bind.annotation.*;

import javax.annotation.Resource;

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

    @PostMapping("/payment/add")
    public CommonResult add(@RequestBody Payment payment) {
        int res = paymentService.add(payment);
        log.info("插入结果:" + res);
        if (res > 0) {
            return new CommonResult(200, "插入数据库成功", res);
        } else {
            return new CommonResult(400, "插入数据库失败");
        }
    }

    @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", payment);
        } else {
            return new CommonResult(404, "没有对应记录,查询 id 为:" + id);
        }
    }
}

测试

启动模块后,使用 Postman 发送请求,(因为浏览器不能够通过 url 直接发送 Post 请求)分别是 Post 请求:127.0.0.1:8001/payment/add?serial=Guest001 和 Get 请求: 127.0.0.1:8001/payment/get/1,能够正常返回数据即可。

热部署(开发时使用,生产环境必须关闭)

导入下面的依赖。

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-devtools</artifactId>
    <scope>runtime</scope>
    <optional>true</optional>
</dependency>

开启自动构建。

SpringCloud 详解(二)插图
SpringCloud 详解(二)插图1

然后修改一下代码,看下控制台是否能自动构建即可。

订单模块(服务消费者)

准备工作

创建一个 Module,一个空的 Maven 项目。并导入下面的依赖。

<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.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <scope>runtime</scope>
        <optional>true</optional>
    </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>

在 resources 文件夹下创建 application.yaml 配置文件,并加入下面的配置。

server:
  port: 80

spring:
  application:
    name: order

创建主启动类。

package ml.guest997;

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

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

POJO 层

就是上面的支付模块的代码,就不再赘述了。

Config 层

package ml.guest997.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();
    }
}

Controller 层

package ml.guest997.controller;

import ml.guest997.pojo.CommonResult;
import ml.guest997.pojo.Payment;
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
public class OrderController {
    public static final String PAYMENT_URL = "http://localhost:8001";

    @Resource
    private RestTemplate restTemplate;

    @GetMapping("/consumer/payment/add")
    public CommonResult add(Payment payment) {
        //三个参数分别表示请求地址、请求参数和响应被转换成的对象类型。
        return restTemplate.postForObject(PAYMENT_URL + "/payment/add", 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);
    }
}

RestTemplate 提供了多种便捷访问远程 http 服务的方法,是一种简单便捷的访问 restful 服务模板类,是 Spring 提供的用于访问 Rest 服务的客户端模板工具集。

测试

将两个模块都启动后,浏览器访问地址:127.0.0.1//consumer/payment/add?serial=Guest002 和 127.0.0.1//consumer/payment/get/2,能够正常返回数据即可。

IDEA 开启 Services

为了方便管理多个微服务,可以通过 IDEA 开启 Services 进行统一管理。

SpringCloud 详解(二)插图2
SpringCloud 详解(二)插图3

工程重构

从上面的两个模块就能看出来,POJO 层的代码是冗余的,可能以后每写一个模块,就需要把这些代码都复制一份,十分的麻烦。我们可以通过新建个 Commons 模块,将这些冗余的代码放进去,在需要的模块下引入这个模块就能实现简单的复用了。

准备工作

创建一个 Module,一个空的 Maven 项目。并导入下面的依赖。

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <scope>runtime</scope>
        <optional>true</optional>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <optional>true</optional>
    </dependency>
    <dependency>
        <groupId>cn.hutool</groupId>
        <artifactId>hutool-all</artifactId>
        <version>5.7.22</version>
    </dependency>
</dependencies>

POJO 层

就是上面两个模块中冗余的 POJO 层代码。然后将另两个模块的 POJO 层删除。

编译打包

通过 IDEA 右侧栏中的 Maven 工具栏,将 Commons 模块编译打包以供其它模块使用。(先 clean 后 install)

SpringCloud 详解(二)插图4

引入依赖

在其它模块的 pom 配置文件中引入下面的依赖。

<dependency>
    <groupId>ml.guest997</groupId>
    <artifactId>Commons</artifactId>
    <version>${project.version}</version>
</dependency>

测试

将两个模块都启动后,通过浏览器访问地址:127.0.0.1//consumer/payment/add?serial=Guest003 和 127.0.0.1//consumer/payment/get/3,能够正常返回数据即可。