SpringCloud学习笔记1——入门篇
@入门篇
入门篇为过渡，还不涉及SpringCloud相关内容。
一、准备工作
1.使用IDEA创建Maven父工程
2.设置
ctrl+alt+s打开设置
①配置字符集编码
②配置注解生效激活
③配置Java编译版本
④文件类型过滤（可选）
3.修改项目
①删除src目录，使项目只保留pom.xml
删除前
删除后
②修改pom文件
先添加如下内容
<packaging>pompackaging>
如图
然后将之后的内容使用如下内容替换
<properties>
<project.build.sourceEncoding>UTF-8project.build.sourceEncoding>
<maven.compiler.source>12maven.compiler.source>
<maven.compiler.target>12maven.compiler.target>
<junit.version>4.12junit.version>
<lombok.version>1.18.10lombok.version>
<log4j.version>1.2.17log4j.version>
<mysql.version>8.0.18mysql.version>
<druid.version>1.1.16druid.version>
<mybatis.spring.boot.version>2.1.1mybatis.spring.boot.version>
properties>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.apache.maven.pluginsgroupId>
<artifactId>maven-project-info-reports-pluginartifactId>
<version>3.0.0version>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-dependenciesartifactId>
<version>2.2.2.RELEASEversion>
<type>pomtype>
<scope>importscope>
dependency>
<dependency>
<groupId>org.springframework.cloudgroupId>
<artifactId>spring-cloud-dependenciesartifactId>
<version>Hoxton.SR1version>
<type>pomtype>
<scope>importscope>
dependency>
<dependency>
<groupId>com.alibaba.cloudgroupId>
<artifactId>spring-cloud-alibaba-dependenciesartifactId>
<version>2.1.0.RELEASEversion>
<type>pomtype>
<scope>importscope>
dependency>
<dependency>
<groupId>mysqlgroupId>
<artifactId>mysql-connector-javaartifactId>
<version>${mysql.version}version>
<scope>runtimescope>
dependency>
<dependency>
<groupId>com.alibabagroupId>
<artifactId>druidartifactId>
<version>${druid.version}version>
dependency>
<dependency>
<groupId>org.mybatis.spring.bootgroupId>
<artifactId>mybatis-spring-boot-starterartifactId>
<version>${mybatis.spring.boot.version}version>
dependency>
<dependency>
<groupId>junitgroupId>
<artifactId>junitartifactId>
<version>${junit.version}version>
dependency>
<dependency>
<groupId>log4jgroupId>
<artifactId>log4jartifactId>
<version>${log4j.version}version>
dependency>
dependencies>
dependencyManagement>
最终pom文件的内容
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0modelVersion>
<groupId>com.hry.springcloudgroupId>
<artifactId>springcloud01artifactId>
<version>1.0-SNAPSHOTversion>
<packaging>pompackaging>
<properties>
<project.build.sourceEncoding>UTF-8project.build.sourceEncoding>
<maven.compiler.source>12maven.compiler.source>
<maven.compiler.target>12maven.compiler.target>
<junit.version>4.12junit.version>
<lombok.version>1.18.10lombok.version>
<log4j.version>1.2.17log4j.version>
<mysql.version>8.0.18mysql.version>
<druid.version>1.1.16druid.version>
<mybatis.spring.boot.version>2.1.1mybatis.spring.boot.version>
properties>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.apache.maven.pluginsgroupId>
<artifactId>maven-project-info-reports-pluginartifactId>
<version>3.0.0version>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-dependenciesartifactId>
<version>2.2.2.RELEASEversion>
<type>pomtype>
<scope>importscope>
dependency>
<dependency>
<groupId>org.springframework.cloudgroupId>
<artifactId>spring-cloud-dependenciesartifactId>
<version>Hoxton.SR1version>
<type>pomtype>
<scope>importscope>
dependency>
<dependency>
<groupId>com.alibaba.cloudgroupId>
<artifactId>spring-cloud-alibaba-dependenciesartifactId>
<version>2.1.0.RELEASEversion>
<type>pomtype>
<scope>importscope>
dependency>
<dependency>
<groupId>mysqlgroupId>
<artifactId>mysql-connector-javaartifactId>
<version>${mysql.version}version>
<scope>runtimescope>
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>junitgroupId>
<artifactId>junitartifactId>
<version>${junit.version}version>
dependency>
<dependency>
<groupId>log4jgroupId>
<artifactId>log4jartifactId>
<version>${log4j.version}version>
dependency>
dependencies>
dependencyManagement>
project>
二、构建项目（支付模块）
1.创建module
表示支付模块，使用端口号为8001
创建完之后查看父工程的pom文件多了module
2.修改pom文件
打开module payment8001的pom文件，原始如上图所示，添加如下依赖：
<dependencies>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-webartifactId>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-actuatorartifactId>
dependency>
<dependency>
<groupId>org.mybatis.spring.bootgroupId>
<artifactId>mybatis-spring-boot-starterartifactId>
dependency>
<dependency>
<groupId>org.springframework.cloudgroupId>
<artifactId>spring-cloud-starter-netflix-eureka-clientartifactId>
dependency>
<dependency>
<groupId>com.alibabagroupId>
<artifactId>druidartifactId>
dependency>
<dependency>
<groupId>mysqlgroupId>
<artifactId>mysql-connector-javaartifactId>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-jdbcartifactId>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-devtoolsartifactId>
<scope>runtimescope>
<optional>trueoptional>
dependency>
<dependency>
<groupId>org.projectlombokgroupId>
<artifactId>lombokartifactId>
<optional>trueoptional>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-testartifactId>
<scope>testscope>
dependency>
dependencies>
8001pom文件完整的内容如下
<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>springcloud01artifactId>
<groupId>com.hry.springcloudgroupId>
<version>1.0-SNAPSHOTversion>
parent>
<modelVersion>4.0.0modelVersion>
<artifactId>cloud-provider-payment8001artifactId>
<dependencies>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-webartifactId>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-actuatorartifactId>
dependency>
<dependency>
<groupId>org.mybatis.spring.bootgroupId>
<artifactId>mybatis-spring-boot-starterartifactId>
dependency>
<dependency>
<groupId>org.springframework.cloudgroupId>
<artifactId>spring-cloud-starter-netflix-eureka-clientartifactId>
dependency>
<dependency>
<groupId>com.alibabagroupId>
<artifactId>druidartifactId>
dependency>
<dependency>
<groupId>mysqlgroupId>
<artifactId>mysql-connector-javaartifactId>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-jdbcartifactId>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-devtoolsartifactId>
<scope>runtimescope>
<optional>trueoptional>
dependency>
<dependency>
<groupId>org.projectlombokgroupId>
<artifactId>lombokartifactId>
<optional>trueoptional>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-testartifactId>
<scope>testscope>
dependency>
dependencies>
project>
3.编写yml文件
①新建application.yml文件
②编写yml
server:
port: 8001 #将端口号设为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: com.mysql.cj.jdbc.Driver #mysql驱动包
url: jdbc:mysql://localhost:3306/dbname?useUnicode=true&characterEncoding=utf-8&useSSL=false
username: root
password: root
mybatis:
mapper-locations: classpath:mapper/*.xml
type-aliases-package: com.hry.springcloud.entities #所有entity别名所在包
如果 driver-class-name报错，可以注释掉父工程中Mysql坐标中的scope
4.创建主启动类
①新建启动类
②编码
使用自定义代码补全live template配置请移步至这篇文章
package com.hry.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.业务代码
①数据库创建语句
CREATE TABLE `payment` (
`id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT 'ID',
`serial` varchar(200) DEFAULT '',
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
②创建实体entities类
在entities包下创建Payment实体类
@Data
@AllArgsConstructor
@NoArgsConstructor
public class Payment implements Serializable {
private Long id;
private String serial;
}
如果id和serial提示 never used 需要在IDEA中安装Lombok插件
创建一个CommonResult实体类
@Data
@AllArgsConstructor
@NoArgsConstructor
public class CommonResult<T> {
/**
* 返回结果 例如404,200
*/
private Integer code;
/**
* 信息 例如success
*/
private String message;
/**
* 结果集 信息体对象
*/
private T data;
public CommonResult(Integer code,String message){
this(code,message,null);
}
}
结构如下
③创建dao层
(1)创建PaymentDao接口
/**
* 这里的注解不是@Repository 是因为Repository在某些时候插入会出现问题
*/
@Mapper
public interface PaymentDao {
public int create(Payment payment);
public Payment getPaymentById(@Param("id") Long id);
}
结构如下
(2)创建Mapper.xml文件
<mapper namespace="com.hry.springcloud.dao.PaymentDao">
<insert id="create" parameterType="Payment" useGeneratedKeys="true" keyProperty="id">
INSERT INTO payment(serial) VALUES(#{serial});
insert>
<resultMap id="BaseResultMap" type="com.hry.springcloud.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>
结构
④创建service层
PaymentService 接口
package com.hry.springcloud.service;
import com.hry.springcloud.entities.Payment;
import org.apache.ibatis.annotations.Param;
public interface PaymentService {
public int create(Payment payment);
public Payment getPaymentById(@Param("id") Long id);
}
PaymentService实现类
@Service
public class PaymentServiceImpl implements PaymentService {
/**
* @Autowired 也可以
*/
@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创建controller层
@RestController
@Slf4j
public class PaymentController {
@Resource
private PaymentService paymentService;
@PostMapping(value = "/payment/create")
public CommonResult create(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,"没有对应记录，查询ID"+id,null);
}
}
}
6.测试
在数据库表中手动插入一条数据：
运行SpringBoot启动类，出现错误
com.sun.jersey.api.client.ClientHandlerException: java.net.ConnectException: Connection refused:
注释子module的pom文件中eureka 的坐标
运行启动类后打开浏览器在地址栏输入
http://localhost:8001/payment/get/1
报错
java.sql.SQLException: The server time zone value '�й���ʱ��' is unrecognized or represents more than one time zone. You must configure either the server or JDBC driver (via the serverTimezone configuration property) to use a more specifc time zone value if you want to utilize time zone support.
问题出现原因：MySQL8.0以上版本没有给定服务器时区
解决办法：①父工程pom中换成MySQL版本换成5.7 ②修改yml文件（推荐）
在spring.datasource.url最后加入&serverTimezone=Asia/Shanghai或者&serverTimezone=UTC
配置文件修正后代码如下
spring:
datasource:
url: jdbc:mysql://localhost:3306/db2020?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone=UTC
测试一下查询，成功了
测试添加，又报错了，报错原因是浏览器使用get请求
解决办法：使用postman模拟请求
打开postman，复制浏览器地址，请求改为POST，成功
查看数据库表，成功了
至此，第一节课完成！