一个毕业后差一点进大厂的程序员的进阶之路——既为巩固知识，也为增长粉丝。

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上一节父工程已经建完，本文开始新建第一个Moule——支付模块。 意在模拟用户下单跳转到支付模块（如支付宝）这样一个过程。

新建Moudle（五大步）

1.建moudle

注意：命名要规范，后面moudle变多，随意命名会分不清。我用的名字是：cloud-provider-payment8001

 

新建完成之后观察父工程pom文件的变化。

2.改pom

修改Moudle的pom文件，不是父工程的，注意。

<?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>cloud2020</artifactId>
        <groupId>com.li.springcloud</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

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

    <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.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>

</project>

补充知识：spring-boot-starter-actuator——监控系统健康情况的工具

在生产环境中，需要实时或定期监控服务的可用性。Spring Boot的actuator（健康监控）功能提供了很多监控所需的接口，可以对应用系统进行配置查看、相关功能统计等。在启动时会有显示。

3.写yml

在子Moudle的resources目录下新建application.yml

server:
  port: 8001


spring:
  application:
    name: cloud-payment-service
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: org.gjt.mm.mysql.Driver
    url: jdbc:mysql://localhost:3306/db2019?useUnicode=true&characterEncoding=utf-8&useSSL=false
    username: root
    password: root

mybatis:
  mapperLocations: classpath:mapper/*.xml
  type-aliases-package: com.li.springcloud.entities

 修改成自己数据库配置。

新建数据库db2019，建表payment。

CREATE TABLE payment (
 id BIGINT(20) NOT NULL AUTO_INCREMENT COMMENT 'ID',
 SERIAL VARCHAR(200) DEFAULT '00000',
 PRIMARY KEY(id)
) ENGINE=INNODB AUTO_INCREMENT=1 DEFAULT CHARSET='utf8'
INSERT INTO payment VALUES(01,'202011061045');
INSERT INTO payment(SERIAL) VALUES('202011061046');

4.主启动

新建主启动类，和springboot一样。注意目录关系，主启动类要建在最外面，不然访问时报：Required request body is missing

package com.li.springcloud;

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);
    }
}

5.业务类

mysql->dao->service->controller->VUE

5.1实体类entities

package com.li.springcloud.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;
}

package com.li.springcloud.entities;

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

/**
 *@Author: 一条IT
 *@Date: 2020/11/5 11:17
 **/

@Data
@AllArgsConstructor
@NoArgsConstructor
public class CommonResult<T> {
//    404 not found
    private Integer code;
    private String message;
    private T data;

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

}

补充知识1：CommenResult

作为返回结果集，无论什么业务，传给前端一个结果，类似“404 not found”。

补充知识2：Lombok：可用来帮助开发人员消除 Java 的冗长代码，尤其是对于简单的 Java 对象（POJO）。它通过注解实现这一目的。

@NoArgsConstructor：生成无参构造器；

@AllArgsConstructor：生成全参构造器

@Data：作用于类上，是以下注解的集合：@ToString @EqualsAndHashCode @Getter @Setter @RequiredArgsConstructor

lombok的使用除了要引入依赖，还要安装插件，依赖已经在pom文件写好。

idea安装

eclipse安装：https://blog.csdn.net/qq_35868412/article/details/93137304

了解更多Lombok：https://www.jianshu.com/p/2543c71a8e45

5.2dao

package com.li.springcloud.dao;

import org.apache.ibatis.annotations.Mapper;
import com.li.springcloud.entities.Payment;
import org.apache.ibatis.annotations.Param;

/**
 * @Author: 一条IT
 * @Date: 2020/11/5 14:00
 */

@Mapper
public interface PaymentDao {
//    新增订单
    public int create(Payment Payment);
//按照id查找订单
    public Payment getPaymentById(@Param("id") Long id);

}

写Mapper，mabits操作

<?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.li.springcloud.dao.PaymentDao">
   <insert id="create" parameterType="Payment" useGeneratedKeys="true" keyProperty="id">
       insert into payment(serial) values(#{serial});
   </insert>
    
    <resultMap id="BaseResultMap" type="com.li.springcloud.entities.Payment">
        <id column="id" property="id" jdbcType="BIGINT"></id>
        <id column="serial" property="serial" jdbcType="VARCHAR"></id>
    </resultMap>
    <select id="getPaymentById" parameterType="Long" resultMap="BaseResultMap">
        select * from payment where id=#{id};
    </select>

</mapper>

 注意：parameterType不要写成parameterMap；id对应方法名，不要手敲，容易错，统统复制粘贴。

5.3service

先写接口，再写实现类。方法同样复制dao的，不要手敲。

package com.li.springcloud.service;

import com.li.springcloud.entities.Payment;
import org.apache.ibatis.annotations.Param;

/**
 * @Author: 一条IT
 * @Date: 2020/11/5 14:20
 */
public interface PaymentService {
    public int create(Payment Payment);

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


}

实现类

package com.li.springcloud.service;

import com.li.springcloud.dao.PaymentDao;
import com.li.springcloud.entities.Payment;
import org.apache.ibatis.annotations.Param;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;

/**
 * @Author: 一条IT
 * @Date: 2020/11/5 14:21
 */

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

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

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


}

 

5.4controller

package com.li.springcloud.controller;

import com.li.springcloud.entities.CommonResult;
import com.li.springcloud.entities.Payment;
import com.li.springcloud.service.PaymentService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.*;

import javax.annotation.Resource;

/**
 * @Author: 一条IT
 * @Date: 2020/11/5 14:33
 */

@RestController
//日志
@Slf4j
public class PaymentController {
//    Java自带的依赖注入：import javax.annotation.Resource;
    @Resource
    private PaymentService paymentService;

    //尽量用新的注解
    @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: ",result);
        }else{
            return new CommonResult(444,"插入数据库失败",null);
        }
    }

    @GetMapping(value = "/payment/get/{id}")
    public CommonResult getPaymentById(@PathVariable("id") Long id){
        Payment payment=paymentService.getPaymentById(id);
        log.info("********查询结果："+payment);

        if (payment!=null){
            return new CommonResult(200,"查询成功",payment);

        }else {
            return new CommonResult(444,"查询失败，id="+id,null);
        }

    }

}

测试模块功能

启动模块

查询订单方法，因为是get请求，浏览器可测。地址栏输入：http://localhost:8001/payment/get/1

新增订单方法，因为是post请求，大部分浏览器不支持，使用postman测试。

postman需要准备的：

1. 选post请求

2. Headers中添加 key: Content-Type value:application/json

3. Body中选raw, JSON

4. 文本框中写入json参数

总结

构建微服务模块五大步

1.建moudle

2.改pom

3.写yml

4.主启动

5.业务类

下一节将会新建另一个模块Order模块，模拟用户下单。